Model or Part Number Catalog & Pricelist Years Brief Description Slide Rule Family Index Indicator Description Slide Rule Material, or for accessories, what models they fit Scales on Front Side Scales on Back Side, or Back of Slide Back of Mannheim Style Rules, or Special Notes Case Details Physical Form Physical Dimensions Scale Size Replacement Indicator Number Replacement Indicator Glass Number Magnifier Number Double Magnifier Number - to be deleted Replacement Case Number Sewed Leather Case Number Magnifier Case Number Match Numbers - last 4724
1861   Xylonite Logarithmic Spiral Curve 1861 None Xylonite . . Spiral drafting curve which can be used to perform logarithmic spiral calculations   Cut clear plastic curve                   4643
10000 1947 Doric Plastic slide rule with trigonometrical scales divided to represent degrees and minutes 10000 (1947) Improved Glass Indicator Plastic DF = CF CI C = D L K A = B ST S = D T .   Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346 4001
10002 1947 Doric Plastic slide rule with trigonometrical scales divided to represent degrees and minutes 10000 (1947) Improved Glass Indicator Plastic DF = CF CI C = D L K A = B ST S = D T .   Duplex   25cm (10 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346 4002
1740N 1887 Thacher's Calculating Instrument 1740 (1887) None . . . . Polished Mahogany Box Cylinder inside revolving cage, mounted on stand   18 inch               4003
1740 1890, 1893, 1895, 1897, 1899 Thacher's Calculating Instrument 1740 (1890) None . . . . Polished Mahogany Box Cylinder inside revolving cage, mounted on stand   18 inch               4004
4012 1900, 1901, 1903, 1906, 1909, 1913, 1915, 1921, 1922, 1925 Thacher's Calculating Instrument (O'Leary Collection) 1740 (1900) None . . . . Polished Mahogany Box Cylinder inside revolving cage, mounted on stand   18 inch               4005
N4012 1927, 1930, 1934, 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Thacher's Calculating Instrument 1740 (1927) None . . . . Polished Mahogany Box Cylinder inside revolving cage, mounted on stand   18 inch               4006
1741 1893, 1895, 1897, 1899 Thacher's Calculating Instrument, with 3 inch reading glass 1741 (1893) None . . . . Polished Mahogany Box Cylinder inside revolving cage, mounted on stand   18 inch               4007
4013 1900, 1901, 1903, 1906, 1909, 1913, 1915, 1921, 1922, 1925 Thacher's Calculating Instrument, with 3 inch reading glass 1741 (1906) None . . . . Polished Mahogany Box Cylinder inside revolving cage, mounted on stand   18 inch               4008
N4013 1927, 1930, 1934, 1936, 1937, 1939, 1942 Thacher's Calculating Instrument, with 3 inch reading glass 1741 (1927) None . . . . Polished Mahogany Box Cylinder inside revolving cage, mounted on stand   18 inch               4009
1742 1895, 1897, 1899 Fuller's Spiral Slide Rule 1742 (1895) Indicator bars, possibly of brass . . . . Mahogany Box Cylinder, with movable outer sleeve   .               4010
4015 1900, 1901, 1903, 1906, 1909, 1913, 1915 Fuller's Spiral Slide Rule 1742 (1909) Indicator bars, possibly of brass . . . . Mahogany Box Cylinder, with movable outer sleeve   .               4011
4015 1921, 1925, 1927 Fuller's Spiral Slide Rule, with table-mountable holder 1742 (1921) Indicator bars, possibly of brass . . . . Mahogany Box Cylinder, with movable outer sleeve   .               4012
1743 1895, 1897, 1899 Charpentier Calculator 1743 (1895) Metal Indicator Metal . . . None listed Circular pocket watch   2.375 Inch               4013
4020 1900, 1901, 1903, 1906, 1909, 1913, 1915, 1921, 1925, 1927, 1930, 1931 Charpentier Calculator, listed as discontinued in the 1934 pricelist 1743 (1906) Metal indicator shaped like an oversized watch hand . . . . None listed Circular pocket watch   2.375 Inch               4014
1743 1/2 1895, 1897, 1899 Boucher Calculator, resembles an ordinary stem-winding watch, with an open face (glazed) back and front. 1743.5 (1895) Metal watch-style hand Metal, with glass crystals covering back and front. . . .   Circular pocket watch   .               4015
4022 1900, 1901, 1903, 1906 Boucher, silvered metal dials 1743.5 (1900) Metal watch-style hand . . . . None listed Circular pocket watch   .               4016
4024 1900, 1901, 1903, 1906 Boucher, enamel, cardboard dials 1743.5 (1900) Metal watch-style hand . . . .   Circular pocket watch   .               4018
4023 1903, 1906 Boucher, with extra hand 1743.5 (1903) Metal watch-style hand . . . . None listed Circular pocket watch   .               4017
4022-A 1903, 1906 Boucher, paper dials 1743.5 (1903) Metal watch-style hand . . . . None listed Circular pocket watch   .               4019
1744 1895 Duplex Slide Rule with arithmetical slide 1744 (1895) Brass Runner engine divided celluloid laminated wood A = B C = D A = BI CI = D "Keuffel & Esser Co. N.Y." is marked just above the second decade of the "A" scale on the back side   Duplex   25cm (10 inch)               4020
1744 1897 Duplex Slide Rule with arithmetical slide (Otnes Collection) 1744 (1897) Brass Runner engine divided celluloid laminated wood A = B C = D A = BI CI = D "Keuffel & Esser Co. N.Y." is marked just below the "D" scale, between the 2 and 3 on the front side   Duplex   25cm (10 inch) . . . . . . . 4586
1744 1899 Duplex Slide Rule with arithmetical slide (Rueb Collection) 1744 (1899) Brass Runner engine divided celluloid laminated wood A = B C = D A = BI CI = D "Keuffel & Esser Co. New-York & Chicago." is marked just below the "D" scale, between the 2 and 3 on the front side   Duplex   25cm (10 inch) . . . . . . . 4640
1744 1/2 1899 Duplex (Hanssen Collection) 1744.5 (1899) Metal Indicator chisel-type indicator engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . . Duplex   12.5cm (5 inch) . . . . . . . 4022
1744A 1895 Duplex Slide Rule, with trigonometrical slide 1744A (1895) Brass Runner chisel-type indicator engine divided celluloid laminated mahogany A = B C = D (Second slide = B C =) A = BI CI = D (Second slide = S L T =) "Keuffel & Esser Co. N.Y." is marked just above the second decade of the "A" scale on the back side   Duplex   25cm (10 inch)               4682
1744B 1895 Duplex Slide Rule, with interchangeable slides both arithmetical and trigonometrical 1744B (1895) Brass Runner chisel-type indicator engine divided celluloid laminated mahogany A = B C = D (Second slide = B C =) A = BI CI = D (Second slide = S L T =) "Keuffel & Esser Co. N.Y." is marked just above the second decade of the "A" scale on the back side   Duplex   25cm (10 inch)               4021
1744B 1897, 1899 Duplex Slide Rule, with interchangeable slides both arithmetical and trigonometrical (Hanssen Collection) 1744B (1897) Brass Runner chisel-type indicator engine divided celluloid laminated mahogany A = B C = D (Second slide = B C =) A = BI CI = D (Second slide = S L T =) "Keuffel & Esser Co. N.Y." is marked just below the "D" scale, between the 2 and 3 on the front side . Duplex   25cm (10 inch) . . . . . . . 4587
479 1881 Engineers Slide Rule, no indicator 1745 (1881) None Boxwood, with ivory slide 10 inch [ A = B B = D ] 25cm . Table of guage points for square, cylinder, and globe. Also a table of guage points for pumping engines, and another table for regular polygons.   Closed Frame   25cm (10 inch)               4484
479-1 1883 Engineers Slide Rule, no indicator 1745 (1883) None possibly boxwood . . .   Closed Frame   25cm (10 inch) . . . . . . . 4023
1745N 1887 Engineers Slide Rule, old number 479-1 1745 (1887) None possibly boxwood . . . None listed Closed Frame   25cm (10 inch) . . . . . . . 4024
1745 1890 Engineers Slide Rule 1745 (1890) None Boxwood 25cm / A = B B = D . # 25cm --> 50cm # None listed Closed Frame   25cm (10 inch) . . . . . . . 4487
1745 1893, 1895 Slide Rule 1745 (1893) None Boxwood 25cm / A = B B = D . # 25cm --> 50cm # None listed Closed Frame   25cm (10 inch) . . . . . . . 4491
1745 1897, 1899 Gunter Slide Rule 1745 (1897) None Polished Boxwood 25cm / A = B B = D . # 25cm --> 50cm # None listed Closed Frame   25cm (10 inch) . . . . . . . 4492
479-2 1883 Engineers Slide Rule 1746 (1883) Brass Indicator possibly boxwood . . .   Closed Frame   25cm (10 inch) . . . . . . . 4025
Unknown Model 1883 Engineers Slide Rule (Otnes Collection) 1746 (1883) Brass Indicator Polished Boxwood 20cm / A = B C = D ] 21cm = S L T (inverted) = Made for K&E by Tavernier-Gravet - conversion table on back # 21cm --> 42cm # . Closed Frame   20cm (8 inch) . . . . . . . 4623
1746N 1887 Engineers Slide Rule, old number 479-2 1746 (1887) Brass Indicator possibly boxwood . .   None listed Closed Frame   25cm (10 inch) . . . . . . . 4026
1746 1890 Engineers Slide Rule 1746 (1890) Brass Indicator engine divided celluloid laminated wood . . # 25cm --> 50cm # None listed Closed Frame   25cm (10 inch) . . . . . . . 4488
1746 1893, 1895 Mannheim Slide Rule 1746 (1893) Brass Indicator engine divided celluloid laminated wood 10 inch / A = B C = D ] 25cm = S L T = # 25cm --> 50cm # "Keuffel & Esser Co. N.Y." is marked just above the 10 inch scale on the wood margin, and not on the celluloid. None listed Closed Frame   25cm (10 inch) . . . . . . . 4489
1746 1897 Mannheim Slide Rule (Rueb Collection) 1746 (1897) Brass Indicator engine divided celluloid laminated wood 10 inch / A = B C = D ] 25cm = S L T = # 25cm --> 50cm # "Keuffel & Esser Co. New-York" is marked just below the "D" scale, between the 2 and 3 on the front side None listed Closed Frame   25cm (10 inch) . . . . . . . 4585
1746 1899 Mannheim Slide Rule (Rueb Collection) 1746 (1899) Brass Indicator engine divided celluloid laminated wood. 10 inch / A = B C = D ] 25cm = S L T = # 25cm --> 50cm # "Keuffel & Esser Co. New-York & Chicago." is marked just below the "D" scale, between the 2 and 3 on the front side None listed Closed Frame   25cm (10 inch) . . . . . . . 4641
1746 1/2 1897 Mannheim Slide Rule (Otnes Collection, without indicator) 1746.5 (1897) Glass Indicator with Metal Frame, two hairlines toward edges of glass engine divided celluloid laminated wood. Stators have beveled ends. 10 inch / A = B C = D ] 25cm = S L T = # 25cm --> 50cm # "Keuffel & Esser Co. New-York" is marked just below the "D" scale, between the 2 and 3 on the front side   Closed Frame   . . . . . . . . 4027
1746 1/2 1899 Mannheim Slide Rule (Suspected to exist) 1746.5 (1899) Glass Indicator with Metal Frame, two hairlines toward edges of glass engine divided celluloid laminated wood. Stators have beveled ends. 10 inch [ A = B B = D ] 25cm = S L T = # 25cm --> 50cm # "Keuffel & Esser Co. New-York & Chicago" is marked just below the "D" scale, between the 2 and 3 on the front side   Closed Frame   . . . . . . . . 4027
479-5 1883 Common Slide Rule, with brass slide 1746a (1883) None Wood, with brass slide A = B B = D . .   Closed Frame   unknown . . . . . . . 4028
1747 1899 Mannheim Slide Rule 1747 (1899) Metal Indicator engine divided celluloid laminated mahogany . . .   Closed Frame   12.5cm (5 inch) . . . . . . . 4029
1748 1890 Engineer's Slide Rule 1748 (1890) Brass Indicator Engine divided celluloid laminated wood . . .   Closed Frame   50cm (20 inch) . . . . . . . 4030
1748 1893, 1895, 1897, 1899 Mannheim Slide Rule 1748 (1893) Brass Indicator Engine divided celluloid laminated wood 50cm / A = B C = D ] 20 inch . # 50cm --> 100cm #   Closed Frame   50cm (20 inch) . . . . . . . 4490
1748 1/2 1897, 1899 Mannheim Slide Rule 1748.5 (1897) Glass Indicator with Metal Frame engine divided celluloid laminated wood 50cm / A = B C = D ] 20 inch . # 50cm --> 100cm #   Closed Frame   50cm (20 inch) . . . . . . . 4032
1749-1 1897 Student's Slide Rule, with paper facing 1749 (1897) Brass Indicator, with thin transparent celluloid marked with a with hairline Thoroughly seasoned hardwood, backed by stout binder's board, with a special strong and tough white paper facing A = B C = D = S L T = Table of the most frequently occurring proportions and formulas [image in catalog is inverted]   Closed Frame   25cm (10 inch) . . . . . . . 4033
1749-1 1899 Student's Slide Rule, with paper facing 1749 (1899) Brass Indicator, with thin transparent celluloid marked with a with hairline wood A = B C = D Unknown unkown   Closed Frame   25cm (10 inch) . . . . . . . 4572
4005N 1909 Improved Reckoning Machine 4005 (1909) None . . . .   Mechanical machine   . . . . . . . . 4034
4006N 1909 Improved Reckoning Machine 4005 (1909) None . . . .   Mechanical machine   . . . . . . . . 4035
4007N 1909 Improved Reckoning Machine 4005 (1909) None . . . .   Mechanical machine   . . . . . . . . 4036
4005 1913, 1915, 1921, 1925 Improved Reckoning Machine, listed as discontinued in the 1925 pricelist 4005 (1913) None . . . .   Mechanical machine   . . . . . . . . 4037
4006 1913, 1915, 1921, 1922, 1925 Improved Reckoning Machine, listed as discontinued in the 1925 pricelist 4005 (1913) None . . . .   Mechanical machine   . . . . . . . . 4038
4007 1913, 1915, 1921, 1925 Improved Reckoning Machine, listed as discontinued in the 1925 pricelist 4005 (1913) None . . . .   Mechanical machine   . . . . . . . . 4039
4008 1952 Elemoto Dimension Adder & Subtractor 4005 (1952) None           Mechanical machine     . . . . . . . 4504
4010 1952 Stima Calculator 4005 (1952) None           Mechanical machine     . . . . . . . 4505
4016 1906 Sperry, watch style, geared differently 4016 (1906) Metal watch-style hand . . . Patent Date October 25, 1904, with round stem and bail, two push buttons at 11 and 1 None listed Circular pocket watch   2.125 inch . . . . . . . 4040
4017 1906 Sperry, watch style, geared the same 4017 (1906) Metal watch-style hand . . . Patent Date October 25, 1904, with round stem and bail, two push buttons at 11 and 1 None listed Circular pocket watch   2.125 inch . . . . . . . 4041
4017 1909 Sperry, watch style, geared the same (Rueb Collection) 4017 (1909) Metal watch-style hand . . . Patent Date October 25, 1904, with two wheels on stem, and fob loop at 8 o'clock None listed Circular pocket watch   2.125 inch . . . . . . . 4651
4017 1913, 1915, 1921, 1922, 1925, 1927, 1930, 1934, 1936, 1937, 1939 Sperry, watch style, geared the same (Rueb Collection) 4017 (1913) Metal watch-style hand . . . Patent Date December 26, 1911, with two wheels on stem, and fob loop at 8 o'clock None listed Circular pocket watch   2.125 inch . . . . . . . 4653
4018 1909 K&E Circular Calculator 4018 (1909) Metal watch-style hand . . . Patent Appl. For, fob loop at 9 o'clock None listed Circular pocket watch   2.125 inch . . . . . . . 4042
4018 1913, 1915, 1921, 1925, 1927 K&E Circular Calculator 4018 (1913) Metal watch-style hand . . . Patented, fob loop at 9 o'clock None listed Circular pocket watch   2.125 inch . . . . . . . 4652
4019 1903, 1906 Goodchild Mathematical Chart (Reproduction in Chamberlain Collection) 4019 (1903) None Stout Paper . . . None listed Paper chart   . . . . . . . . 4043
4019A 1903, 1906 Goodchild Mathematical Chart 4019 (1903) None Neatly mounted on fine quality drawing board, (showing both sides of chart) with protective coating . . . None listed Paper chart   . . . . . . . . 4044
4019B 1903, 1906 Triangular Rule for Goodchild (Chamberlain Collection) 4019 (1903) Boxwood Boxwood . . . None listed Triangular rule   . . . . . . . . 4045
4028 1900, 1901, 1903, 1906 Gunter 4028 (1906) None boxwood 25cm / A = B B = D = S T L = # 25cm --> 50cm # None listed Closed Frame   25cm (10 inch) . . . . . . . 4046
4030 1900, 1901 K&E Patent Adjustable (Mannheim) Slide Rule 4030 (1900) Brass Indicator engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm = S T L = Subdivided as close as a 10 inch rule Sewed Leather Sheath Closed Frame   12.5cm (5 inch) . . . . . . . 4047
4031 1900, 1901 Mannheim Adjustable 4031 (1901) Two Line Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm = S T L = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Sheath Closed Frame   12.5cm (5 inch) A, 99-6801 1, 1W, 99-6813     O OM 4048
4031 1903, 1906, 1909, 1913 Mannheim Adjustable (Castleberry Collection) 4031 (1903) Glass Indicator with Metal Frame, Two Line indicator was optional engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm =S L T = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Case Closed Frame   12.5cm (5 inch) A, 99-6801 1, 1W, 99-6813     O OM 4049
4031 1914 Mannheim Adjustable (Rueb Collection) (McCoy Collection) 4031 (1914) Frameless Glass Indicator with metal indicator bars engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm =S L T = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Case Closed Frame   12.5cm (5 inch) A, 99-6801 1, 1W, 99-6813     O OM 4519
4031 1915, 1921 Mannheim Adjustable (Rueb Collection) (O'Leary Collection) 4031 (1915) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm =S L T = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Case Closed Frame   12.5cm (5 inch) A, 99-6801 1, 1W, 99-6813     O OM 4050
4031S 1922 Mannheim Adjustable (O'Leary Collection) 4031 (1922) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm =S L T = K&E conversion table Sewed Leather Sheath Closed Frame   12.5cm (5 inch) A, 99-6801 1, 1W, 99-6813     O OM 4051
4031S 1925, 1927, 1928, 1930, 1934, 1936, 1937, 1939 Mannheim Adjustable (Rueb Collection) (McCoy Collection) 4031 (1925) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm =S L T = NBS Circular 47 conversion table Sewed Leather Sheath Closed Frame   12.5cm (5 inch) A, 99-6801 1, 1W, 99-6813     O OM 4052
4032 1900, 1901 Mannheim 4032 (1901) Indicator with reading lens engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm =S T L = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Sheath Closed Frame   12.5cm (5 inch)               4688
4032 1903, 1906 Mannheim 4032 (1901) Indicator with reading lens engine divided celluloid laminated mahogany 5inch / A =B C = D ] 13cm =S L T = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Sheath Closed Frame   12.5cm (5 inch)               4053
4035 1906, 1909, 1913 Patent Adjustable (Mannheim) (O'Leary Collection) 4035 (1906) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 8inch / A =B C = D ] 21cm # Pat. June 5, 1900 # =S L T = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Sheath Closed Frame   20cm (8 inch) B, 99-6802 2, 2W, 99-6814       P PM 4054
4035 1914 Patent Adjustable (Mannheim) 4035 (1914) Frameless Glass Indicator with metal indicator bars engine divided celluloid laminated mahogany 8inch / A =B C = D ] 21cm =S L T = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Case Closed Frame   20cm (8 inch) B, 99-6802 2, 2W, 99-6814       P PM 4520
4035 1915, 1921 Patent Adjustable (Mannheim) (Rueb Collection) 4035 (1915) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 8inch / A =B C = D ] 21cm =S L T = K&E conversion table (subdivided as closely as the 10 inch 4041) Sewed Leather Case Closed Frame   20cm (8 inch) B, 99-6802 2, 2W, 99-6814       P PM 4056
4035S 1922, 1925 Mannheim Adjustable 4035 (1922) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 8inch / A =B C = D ] 21cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   20cm (8 inch) B, 99-6802 2, 2W, 99-6814       P PM 4057
N4035S 1927, 1928, 1930, 1936 Mannheim Adjustable 4035 (1927) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 8inch / A =B C = D ] 21cm =S L T = . Sewed Leather Case Closed Frame   20cm (8 inch) B, 99-6802 2, 2W, 99-6814 4085-B, 4185-B, 4185-1, 68-2230     P PM 4058
N4035S 1937, 1939 Mannheim Adjustable 4035 (1937) Improved Glass Indicator engine divided celluloid laminated mahogany 8inch / A =B C = D ] 21cm =S L T = . Sewed Leather Case Closed Frame   20cm (8 inch) E, 68-2139 4, 4W, 68-2191 4085-B, 4185-B, 4185-1, 68-2230     P PM 4059
4040 1901 Mannheim (Rueb Collection) 4040 (1901) Metal Indicator engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table #27cm - 52cm# Marked "PAT. June 5, 1900" in well. Has the three screw adjustable feature Two part hard case Closed Frame   25cm (10 inch)               4060
No Number on rule 1900? Mannheim "American", (O'Leary Collection) 4041 (1900) Glass Indicator with Metal Frame engine divided celluloid laminated blond hardwood, with printed inch and cm rules. 10inch / A =B C = D ] 26cm =S L T = K&E conversion table #26cm - 51cm# Marked "PAT APPLD FOR" in well. Has the three screw adjustable feature Two part hard case Closed Frame   25cm (10 inch)               4584
Unknown 1900? Mannheim "American", (John Prince Collection) 4041 (1900) Glass Indicator with Metal Frame engine divided celluloid laminated blond hardwood, with printed inch and cm rules. 10inch / A =B C = D ] 26cm =S L T = K&E conversion table #26cm - 51cm# Non-adjustable Two part hard case Closed Frame   25cm (10 inch)               4630
4041 1901 Mannheim Adjustable (O'Leary Collection) 4041 (1901) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 26cm =S L T = K&E conversion table #26cm - 51cm# No model number shown Morocco Case Closed Frame   25cm (10 inch)               4658
Unknown 1902 (?) Mannheim Adjustable (Rueb Collection) 4041 (1902) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 26cm =S L T = K&E conversion table #26cm - 51cm# No model number shown Keuffel & Esser Co. NY on left end of slide Two part hard case Closed Frame   25cm (10 inch)               4660
Unknown 1902 (?) Mannheim Adjustable (Rueb Collection) 4041 (1902) Optional Two Line Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 26cm =S L T = K&E conversion table No model number shown Keuffel & Esser Co. NY on left end of slide Two part hard case Closed Frame   25cm (10 inch)               4659
4041 1903 Mannheim Adjustable (Rueb Collection) 4041 (1903) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table #27cm - 52cm# No model number shown Two part hard case Closed Frame   25cm (10 inch)               4655
4041 1906 Mannheim Adjustable (O'Leary Collection) 4041 (1906) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table #27cm - 52cm# No model number shown Two part hard case Closed Frame   25cm (10 inch)               4061
4041 1908 (?) Mannheim Adjustable (Guare Collection) 4041 (1908) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table #27cm - 52cm# <4041> on left end of slide Two part hard case Closed Frame   25cm (10 inch)               4678
4041 1909 Mannheim Adjustable (O'Leary Collection) 4041 (1909) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table Two part hard case Closed Frame   25cm (10 inch)               4656
4041 1909 Mannheim Adjustable (Castleberry Collection) Special Order 4041 (1909) Glass Indicator with Decimal Pointer (model # 4086) (Special Order Option) engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table Two part hard case Closed Frame   25cm (10 inch)               4680
4041S 1909 Mannheim Adjustable 4041 (1909) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table Sewed Leather Sheath Closed Frame   25cm (10 inch)               4063
4041 1913 Mannheim Adjustable 4041 (1913) Glass Indicator with Metal Frame engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Morocco Case Closed Frame   25cm (10 inch)               4064
4041 1914 Mannheim Adjustable (O'Leary Collection) 4041 (1914) Frameless Glass Indicator with metal indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Morocco Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4483
4041 1915 Mannheim Adjustable 4041 (1915) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Morocco Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4066
4041 1921 Mannheim Adjustable (Guare Collection) 4041 (1921) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table, white face in well with Pat June 5, 1900 Two part hard case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4518
4041 1921, 1922 Mannheim Adjustable (Rueb Collection) Special Order 4041 (1921) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table, special order with Quotient +1 and Product -1 on right of slide Two part hard case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4654
4041 1921, 1922 Mannheim Adjustable (O'Leary Collection) Special Order 4041 (1921) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table, special order with Quotient +1 and Product -1 on right of slide Sewed Leather Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4676
4041 1922 Mannheim Adjustable (Guare Collection) (Castleberry Collection) 4041 (1922) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 27cm =S L T = K&E conversion table, Exposed wood in well.Pat June 5, 1900 below D scale after 3 Two part hard case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4677
4041S 1922 Mannheim Adjustable 4041 (1922) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4069
N 4041 1924 (?) Mannheim Adjustable (Marked N<4041>) (Castleberry Collection) 4041 (1924) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Two part hard case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4679
N 4041S 1924 (?) Mannheim Adjustable (Marked N<4041>) (Rueb Collection) 4041 (1924) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4055
4041 1925 Mannheim Adjustable (O'Leary Collection) 4041 (1925) Frameless Glass Indicator with plastic indicator bars engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table, special order with Quotient +1 and Product -1 on right of slide Flap Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4675
N4041 1925, 1927, 1928, 1930, 1934 Mannheim Adjustable (Rueb Collection) 4041 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4070
N4041S 1925, 1927, 1928, 1930, 1934 Mannheim Adjustable 4041 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4073
N4041 1935 Mannheim Adjustable (O'Leary Collection) 4041 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4074
N4041S 1935 Mannheim Adjustable 4041 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4077
N4041 1936, 1937, 1939, 1942, 1943 Mannheim Adjustable 4041 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4078
N4041S 1936, 1937, 1939, 1942, 1943 Mannheim Adjustable 4041 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4079
4041F 1906 Mannheim Adjustable, graduated as closely as a 50cm rule (Rueb Collection) 4041F (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table. Number shown on rule as 4041F Two part hard case Closed Frame   25cm (10 inch)               4062
4041F 1909 Mannheim Adjustable, graduated as closely as a 50cm rule (Rueb Collection) 4041F (1909) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table. Number shown on rule as <4041F> Two part hard case Closed Frame   25cm (10 inch)               4657
4041F 1913 Mannheim Adjustable, graduated as closely as the 50cm rule 4041F (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Morocco Case Closed Frame   25cm (10 inch)               4065
4041F 1914 Mannheim Adjustable, graduated as closely as the 50cm rule 4041F (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Morocco Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4522
4041F 1915, 1921, 1922 Mannheim Adjustable, graduated as closely as the 50cm rule (O'Leary Collection) 4041F (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S T L = K&E conversion table Note that scales on back of slide are switched to STL Morocco Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4067
4041FS 1922 Mannheim Adjustable, graduated as closely as the 50cm rule 4041F (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) D, 99-6804 3, 99-6815           4068
N4041F 1924 (?) Mannheim Adjustable, graduated as closely as the 50cm rule (Rueb Collection) 4041F (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = K&E conversion table Number shown on rule as N <4041F>   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4661
N4041F 1925, 1927, 1928, 1930 Mannheim Adjustable, graduated as closely as the 50cm rule 4041F (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4071
N4041FS 1925, 1927, 1928, 1930 Mannheim Adjustable, graduated as closely as the 50cm rule 4041F (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4072
N4041F 1933, 1934 Mannheim Adjustable, not divided throughout as closely as the 50cm rule. 4041F (1933) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4506
N4041FS 1933, 1934 Mannheim Adjustable, not divided throughout as closely as the 50cm rule 4041F (1933) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4510
N4041F 1935 Mannheim Adjustable, graduated as closely as the 50cm rule 4041F (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4075
N4041FS 1935 Mannheim Adjustable, graduated as closely as the 50cm rule 4041F (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4076
4045 1906, 1909 Mannheim Adjustable 4045 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 10inch / A =B C = D ] 42cm =S L T = K&E conversion table   Closed Frame   42cm (16 inch)     4085-B, 4185-B, 4185-1, 68-2230     S SM 4080
4045 1913 Mannheim Adjustable 4045 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 16inch / A =B C = D ] 42cm =S L T = K&E conversion table Morocco Case Closed Frame   42cm (16 inch)     4085-B, 4185-B, 4185-1, 68-2230     S SM 4081
4045 1914 Mannheim Adjustable 4045 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 42cm =S L T = K&E conversion table   Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4523
4045 1915, 1921 Mannheim Adjustable (O'Leary Collection) 4045 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 42cm =S L T = K&E conversion table Two part hard case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4082
4045 1922 Mannheim Adjustable (Rueb Collection) 4045 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = K&E conversion table Two part hard case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4664
4045S 1922 Mannheim Adjustable 4045 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4083
4045 1925, 1927, 1928, 1930 Mannheim Adjustable (Castleberry Collection) 4045 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = NBS Circular 47 conversion table Flap Case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4662
4045S 1925, 1927, 1928, 1930 Mannheim Adjustable 4045 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4663
4045 1934 Mannheim Adjustable 4045 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = NBS Circular 47 conversion table Two part hard case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4666
4045S 1934 Mannheim Adjustable 4045 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4667
4045 1935 Mannheim Adjustable (Rueb Collection) 4045 (1935) Improved Glass Indicator, marked Patent Pending Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = NBS Circular 47 conversion table Hard case Closed Frame   42cm (16 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230     S SM 4665
4045S 1935 Mannheim Adjustable 4045 (1935) Improved Glass Indicator, marked Patent Pending Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   42cm (16 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     S SM 4673
4045 1936, 1937 Mannheim Adjustable, listed as discontinued in 1939 pricelist 4045 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 40cm =S L T = NBS Circular 47 conversion table Hard case Closed Frame   42cm (16 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230     S SM 4084
4045S 1936, 1937 Mannheim Adjustable, listed as discontinued in 1939 pricelist 4045 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 16inch / A = B C = D ] 42cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   42cm (16 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230     S SM 4085
4050 1900, 1901 Mannheim Adjustable 4050 (1900) Metal Indicator Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S T L = K&E conversion table No model number shown Two part hard case Closed Frame   50cm (20 inch)               4086
4051 1901 Mannheim Adjustable (Rueb Collection) 4051 (1901) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S T L = K&E conversion table Kueffel & Esser Co. marked at 2.3 below D scale Two part hard case Closed Frame   50cm (20 inch)     4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4670
4051 1902 (?) Mannheim Adjustable (Rueb Collection) 4051 (1902) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S T L = K&E conversion table Kueffel & Esser Co. marked at left end of slide Two part hard case Closed Frame   50cm (20 inch)     4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4690
4051 1903 Mannheim Adjustable 4051 (1903) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S L T = K&E conversion table No model number shown Two part hard case Closed Frame   50cm (20 inch)     4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4689
4051 1906, 1909 Mannheim Adjustable 4051 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S L T = K&E conversion table Two part hard case Closed Frame   50cm (20 inch)     4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4087
4051 1913 Mannheim Adjustable 4051 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S L T = K&E conversion table Morocco Case Closed Frame   50cm (20 inch)     4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4088
4051 1914 Mannheim Adjustable 4051 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S L T = K&E conversion table Two part hard case Closed Frame   50cm (20 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4524
4051 1915, 1921 Mannheim Adjustable 4051 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 52cm =S L T = K&E conversion table Two part hard case Closed Frame   50cm (20 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4089
4051 1922 Mannheim Adjustable 4051 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = K&E conversion table Two part hard case Closed Frame   50cm (20 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4671
4051S 1922, 1925, 1927, 1928, 1930 Mannheim Adjustable 4051 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4090
4051 1925, 1927, 1928, 1930 Mannheim Adjustable 4051 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = NBS Circular 47 conversion table Two part hard case Closed Frame   50cm (20 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4669
4051 1934 Mannheim Adjustable 4051 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = NBS Circular 47 conversion table Two part hard case Closed Frame   50cm (20 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4624
4051S 1934 Mannheim Adjustable (Rueb Collection) 4051 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4668
4051 1935 Mannheim Adjustable 4051 (1935) Improved Glass Indicator, marked Patent Pending Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = NBS Circular 47 conversion table Hard case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4672
4051 1936, 1937 Mannheim Adjustable, listed as discontinued in 1939 pricelist (Rueb Collection) 4051 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = NBS Circular 47 conversion table Hard case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4091
4051S 1936, 1937 Mannheim Adjustable, listed as discontinued in 1939 pricelist (O'Leary Collection) 4051 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 20inch / A = B C = D ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4092
4001 seen on eBAY ?? #445653030 Mannheim Adjustable 4053 (1900) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany . . .   Closed Frame   25cm (10 inch) E 4, 4W     O OM 4093
4153-1 1960 Polyphase Pocket 4053-1 (1960) Improved Glass Indicator Ivorite Precision Molded ABS A =B CI C = D K =S L T = . Leather Sheath Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230   AA, AF, 68-2349, 68-2352   4097
4153-1C 1960 Polyphase Pocket 4053-1 (1960) Improved Glass Indicator Ivorite Precision Molded ABS A =B CI C = D K =S L T = . leather sheath, with leather covered pocket clip Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230   AA, AF, 68-2349, 68-2352   4098
68-1643 1962, 1964, 1966, 1967, 1972 Polyphase Pocket 4053-1 (1962) Improved Glass Indicator Ivorite Precision Molded ABS A =B CI C = D K =S L T = . leather sheath, with leather covered pocket clip Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230   AA, AF, 68-2349, 68-2352   4099
68-1648 1962, 1964, 1966, 1967 Polyphase Pocket 4053-1 (1962) Improved Glass Indicator Ivorite Precision Molded ABS A =B CI C = D K =S L T = . leather sheath Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230   AA, AF, 68-2349, 68-2352   4100
4053-2 1913 Polyphase (Mannheim) Slide Rule, K&E Patent Adjustable 4053-2 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 8inch / A = B CI C = D ] K =S L T = K&E conversion table Sewed Leather Case Closed Frame   20cm (8 inch)     4085-B, 4185-B, 4185-1, 68-2230     P PM 4101
4053-2 1914 Polyphase Mannheim Adjustable (O'Leary Collection) 4053-2 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany 8inch / A = B CI C = D ] K =S L T = K&E conversion table Sewed Leather Case Closed Frame   20cm (8 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     P PM 4525
4053-2 1915, 1921 Polyphase Mannheim Adjustable (O'Leary Collection) 4053-2 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B CI C = D ] K =S L T = K&E conversion table L scale is not labeled Sewed Leather Case Closed Frame   20cm (8 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     P PM 4102
N4053-2S 1922 Mannheim Adjustable 4053-2 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B CI C = D K ] (20cm ?) =S L T = K&E conversion table Sewed Leather Case Closed Frame   20cm (8 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     P PM 4103
N4053-2S 1923 Mannheim Adjustable (Guare Collection) 4053-2 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B CI C = D K ] 20cm =S L T = K&E conversion table model number on rule is N <4053-2> Sewed Leather Case Closed Frame   20cm (8 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     P PM 4687
N4053-2S 1924? Mannheim Adjustable (Rueb Collection) 4053-2 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B CI C = D K ] 20cm =S L T = NBS Circular 47 conversion table model number on rule is N <4053-2> Sewed Leather Case Closed Frame   20cm (8 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     P PM 4694
N4053-2S 1925, 1927, 1928, 1930, 1934 Polyphase Mannheim Adjustable (Rueb Collection) 4053-2 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B CI C = D K ] 20cm =S L T = NBS Circular 47 conversion table number on rule is <N4053-2> Sewed Leather Case Closed Frame   20cm (8 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     P PM 4104
N4053-2S 1935 Polyphase Mannheim Adjustable (O'Leary Collection) 4053-2 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 8inch / A = B CI C = D K ] 20cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   20cm (8 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230     P PM 4691
N4053-2S 1936, 1937, 1939 Polyphase Mannheim Adjustable, listed as discontinued in 1939 pricelist (O'Leary Collection) 4053-2 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 8inch / A = B CI C = D K ] 20cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   20cm (8 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230     P PM 4105
4053 1909 Polyphase Slide Rule, K&E Patent Adjustable, (O'Leary Collection) 4053-3 (1909) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 10inch / A = B CI C = D ] K = S L T = K&E conversion table L scale is not labeled Morocco Case Closed Frame   25cm (10 inch)               4094
4053-3 1913 Polyphase (Mannheim) Slide Rule, K&E Patent Adjustable, (O'Leary Collection) 4053-3 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 10inch / A = B CI C = D ] K =S L T = K&E conversion table L scale is not labeled Sewed Leather Case Closed Frame   25cm (10 inch)     4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4106
4053-3 1914 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D ] K =S L T = K&E conversion table L scale is not labeled   Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4498
4053-3 1915, 1921 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D ] K =S L T = K&E conversion table L scale is not labeled   Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4107
4053-3 1922 Polyphase Mannheim Adjustable 4053-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table (addition of the 25cm scale, with K moved to top face) L scale is not labeled   Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4108
4053-3S 1922 Polyphase Mannheim Adjustable 4053-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table (addition of the 25cm scale, with K moved to top face) L scale is not labeled Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4109
N4053-3 1923 Polyphase Mannheim Adjustable 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as N <4053-3> 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table L scale is not labeled Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE SLIDE RULE" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4695
N4053-3 1923 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "N <4053-3>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table L scale is not labeled Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE SLIDE RULE" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4560
N4053-3S 1923 Polyphase Mannheim Adjustable 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as N <4053-3> 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table L scale is not labeled Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4699
N4053-3S 1923 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "N <4053-3>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table L scale is not labeled Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4700
N4053-3 1924 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "<N4053-3>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE SLIDE RULE 4053-3" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4581
N4053-3S 1924 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "<N4053-3>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4701
N4053-3 1925, 1927, 1928, 1930, 1934 Polyphase Mannheim Adjustable 4053-3 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE Reg. U.S. Pat. Off.SLIDE RULE 4053-3" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4110
N4053-3S 1925, 1927, 1928, 1930, 1934 Polyphase Mannheim Adjustable 4053-3 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4111
N4053-3 1935 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Indicator marked Pat 8-17-15 Pat. Pend. Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE Reg. U.S. Pat. Off.SLIDE RULE 4053-3" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4112
N4053-3S 1935 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4580
N4053-3 1936, 1937, 1939, 1942, 1943 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on RIGHT END of slide. 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table hardcase with snap flap. Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4113
N4053-3S 1936, 1937, 1939, 1942, 1943 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on RIGHT END of slide. 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4114
N4053-3 1944, 1947, 1949 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on LEFT END of slide, with stylized K+E on right end. 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table hardcase with leather flap Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4716
N4053-3S 1944, 1947, 1949 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on LEFT END of slide, with stylized K+E on right end. 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4717
N4053-3 1952 Polyphase Mannheim Adjustable (Rueb Collection) 4053-3 (1952) Improved Glass Indicator Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Hardcase with leather flap Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4615
N4053-3S 1952 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1952) Improved Glass Indicator Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Synthetic Leather Case Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4579
N4053-3S 1953? Polyphase Mannheim Adjustable 4053-3 (1953?) Improved Glass Indicator Engine divided celluloid laminated mahogany, with pinned bottom rail 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4561
100 1952, 1954, 1955 Demonstration Slide Rule, Mannheim type, two screw eyes for suspending 4053-3 (1954) Frameless plastic indicator with wooden indicator bars Wood, composition unspecified in catalogs A = B CI C = D K =S L T = .   Closed Frame   7 feet               4116
4053-3 1954, 1955 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1954) Wide Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = New K&E conversion table Synthetic Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4117
4053-3S 1954, 1955 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1954) Wide Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = New K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4118
D4053-3 1954, 1955 Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1954) Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = S&T scales graduated in degrees and decimal parts of a degree New K&E conversion table Synthetic Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4698
D4053-3S 1954, 1955 Polyphase Mannheim Adjustable (Rueb Collection) 4053-3 (1954) Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = S&T scales graduated in degrees and decimal parts of a degree New K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4549
D4053-3SM 1959 Polyphase Mannheim Adjustable (Rueb Collection) 4053-3 (1959) Unbreakable Indicator with magnifier Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = S&T scales graduated in degrees and decimal parts of a degree New K&E conversion table Special issue to US Military. Magnifier Type Sewed Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4710
4053-3 1956? Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1956) Narrow Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = New K&E conversion table Synthetic Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4582
4053-3S 1956? Polyphase Mannheim Adjustable, (O'Leary Collection) 4053-3 (1956) Narrow Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = New K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4583
68-1617 1962, 1967 Polyphase, (O'Leary Collection) 4053-3 (1962) Narrow Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = New K&E conversion table Sewed Leather Case, chamois lined Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4119
68-1622 1962, 1967 Polyphase, (O'Leary Collection) 4053-3 (1962) Narrow Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = New K&E conversion table Synthetic Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4120
68-1944 1962, 1967 Demonstration rule, for use with 4053, 4158, 68-1892 4053-3 (1962) Frameless plastic indicator with wooden indicator bars redwood A =B CI C = D K =S L T = .   Closed Frame   7 Feet               4121
D68-1617 1962, 1967 Polyphase, marked with model number on left end of slide, from collection of Dave Rueb 4053-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back (Rueb Collection) 10inch / A = B CI C = D K \ 25cm =S L T = S&T scales graduated in degrees and decimal parts of a degree New K&E conversion table Sewed Leather Case, chamois lined Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4550
D68-1617 1962, 1967 Polyphase, marked with model number on right end of slide 4053-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with molded plastic back 10inch / A = B CI C = D K \ 25cm =S L T = S&T scales graduated in degrees and decimal parts of a degree K&E conversion table, seen on eBay Sewed Leather Case, chamois lined Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4551
4053-3F 1913 Polyphase (Mannheim) Slide Rule, K&E Patent Adjustable, graduated as closely as the 50cm rule (Otnes Collection) (Magnifier version - Chamberlain Collection) 4053-3F (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 10inch / A = B CI C = D ] K = S T L = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4122
4053-3F 1914 Polyphase Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1914) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D ] K =S L T = K&E conversion table   Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4526
4053-3F 1915, 1921 Polyphase Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D ] K =S L T = K&E conversion table   Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4123
4053-3F 1922 Polyphase Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table   Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4124
4053-3FS 1922 Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4125
N4053-3F 1923 Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as N <4053-3F> 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE SLIDE RULE" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4707
N4053-3F 1923 Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "N <4053-3F>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE SLIDE RULE" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4706
N4053-3FS 1923 Mannheim Adjustable, graduated as closely as the 50cm rule (Rueb Collection) 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as N <4053-3F> 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4705
N4053-3FS 1923 Mannheim Adjustable, graduated as closely as the 50cm rule (Rueb Collection) 4053-3 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "N <4053-3F>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4704
N4053-3F 1924 Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "<N4053-3F>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE SLIDE RULE 4053-3" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4703
N4053-3F 1924 Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "<N4053-3F>" 10inch / A = B CI C = D K ] 25cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4702
N4053-3F 1925, 1927, 1928, 1930 Polyphase Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as "N <4053-3F>" 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Hardcase with card flap Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4126
N4053-3FS 1925 Mannheim Adjustable, graduated as closely as the 50cm rule (O'Leary Collection) 4053-3F (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, Model number shown as N <4053-3F> 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table This is a very rare variant, as "N" should be inside <> marks with NBS table on back. Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4708
N4053-3FS 1925, 1927, 1928, 1930 Polyphase Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4127
N4053-3F 1934 Polyphase Mannheim Adjustable, not divided throughout as closely as the 50cm rule. 4053-3F (1934) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4507
N4053-3FS 1934 Polyphase Mannheim Adjustable, not divided throughout as closely as the 50cm rule 4053-3F (1934) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4511
N4053-3F 1936, 1937, 1939, 1942 Polyphase Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4128
N4053-3FS 1936, 1937, 1939, 1942 Polyphase Mannheim Adjustable, graduated as closely as the 50cm rule 4053-3F (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 10inch / A = B CI C = D K ] 25cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4129
4053-5 1913 Polyphase (Mannheim) Slide Rule, K&E Patent Adjustable 4053-5 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   50cm (20 inch)     4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4130
4053-5 1914 Polyphase Mannheim Adjustable (Rueb Collection) 4053-5 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany 20inch / A = B CI C = D ] K =S T L = K&E conversion table   Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4527
4053-5 1915, 1921 Polyphase Mannheim Adjustable (Rueb Collection) 4053-5 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 20inch / A = B CI C = D ] K =S L T = K&E conversion table   Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4131
4053-5 1922 Polyphase Mannheim Adjustable 4053-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table   Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4132
4053-5S 1922 Polyphase Mannheim Adjustable 4053-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4133
N4053-5 1923 Polyphase Mannheim Adjustable (Rueb Collection) 4053-5 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked N <4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table   Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4721
N4053-5S 1923 Polyphase Mannheim Adjustable 4053-5 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked N <4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4722
N4053-5 1923 Polyphase Mannheim Adjustable (O'Leary Collection) 4053-5 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked N <4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table   Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4686
N4053-5S 1923 Polyphase Mannheim Adjustable (Rueb Collection) 4053-5 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked N <4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4720
N4053-5 1924 Polyphase Mannheim Adjustable 4053-5 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked N <4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table   Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4696
N4053-5S 1924 Polyphase Mannheim Adjustable 4053-5 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked N <4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4723
N4053-5 1925, 1927, 1928, 1930, 1934 Polyphase Mannheim Adjustable 4053-5 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked <N4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table   Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4134
N4053-5S 1925, 1927, 1928, 1930, 1934 Polyphase Mannheim Adjustable 4053-5 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, marked <N4053-5> 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4135
N4053-5 1935 Polyphase Mannheim Adjustable (Rueb Collection) 4053-3 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table Indicator marked Pat 8-17-15 Pat. Pend. Hardcase with card flap, gold embossed lettering, "K&E POLYPHASE SLIDE RULE 4053-5" Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4718
N4053-5S 1935 Polyphase Mannheim Adjustable 4053-3 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table Indicator marked Pat 8-17-15 Pat. Pend. Sewed Leather Case Closed Frame   25cm (10 inch) FL, 99-6806 4, 4W 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4719
N4053-5 1936, 1937, 1939, 1942, 1943 Polyphase Mannheim Adjustable (Rueb Collection) 4053-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on RIGHT END of slide. 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table   Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4136
N4053-5S 1936, 1937, 1939, 1942, 1943 Polyphase Mannheim Adjustable 4053-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on RIGHT END of slide. 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4137
Mystery 1939 Mystery Rule (Rueb Collection) Mystery (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany, no model number 50cm / A = B CI C = D L ] K =S A T = NBS Circular 47 conversion table, Serial Number 836349   Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4724
N4053-5 1944, 1947, 1949, 1952 Polyphase Mannheim Adjustable 4053-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on LEFT END of slide, with stylized K+E on right end. 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table   Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4714
N4053-5S 1944, 1937, 1949, 1952 Polyphase Mannheim Adjustable 4053-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany, model number on LEFT END of slide, with stylized K+E on right end. 20inch / A = B CI C = D K ] 50cm =S L T = NBS Circular 47 conversion table Sewed Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4715
N4053-5 1954 Polyphase Mannheim Adjustable (Rueb Collection) 4053-5 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Synthetic Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4138
N4053-5S 1954 Polyphase Mannheim Adjustable (Manuel Pacheco Fernandez Collection) 4053-5 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4139
4053-5 1960 Polyphase Mannheim Adjustable (Rueb Collection) 4053-5 (1960?) Improved Glass Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Synthetic Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4711
4053-5S 1960 Polyphase Mannheim Adjustable 4053-5 (1960?) Improved Glass Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Sewed Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4712
68-1607 1962 Polyphase Mannheim Adjustable 4053-5 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Sewed Leather Case, chamois lined Closed Frame   50cm (20 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4140
68-1612 1962 Polyphase Mannheim Adjustable 4053-5 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Synthetic Leather Case Closed Frame   50cm (20 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4141
68-1608 1967 Polyphase 4053-5 (1967) Unbreakable Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Sewed Leather Case, chamois lined Closed Frame   50cm (20 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4142
68-1613 1967 Polyphase 4053-5 (1967) Unbreakable Indicator Engine divided celluloid laminated mahogany 20inch / A = B CI C = D K ] 50cm =S L T = K&E conversion table Synthetic Leather Case Closed Frame   50cm (20 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4143
1748-3 1899 Favorite 4054 (1899) Glass Indicator, with single hairline, with Metal Frame possibly boxwood, with lithographic scales A = B C = D =S L T = 10 inch 25cm   Closed Frame   25cm (10 inch) . . . . . . . 4031
4054 1901, 1903, 1906, 1909, 1913, 1915, 1921, 1922, 1925 Favorite (Mannheim) (O'Leary Collection) Dropped from catalog in 1927 4054 (1901) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D =S L T = K&E conversion table   Closed Frame   25cm (10 inch)     4085-B, 4185-B, 4185-1, 68-2230       4634
4054 1944, 1947, 1949, 1952 Polyphase (Mannheim) Adjustable, (Listed as temporarily discontinued in 1952 Pricelist) 4054 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany A = B CI C = D K =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191           4145
4055 1927, 1928, 1930, 1934 Favorite Adjustable (Mannheim) 4055 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230       4146
4055 1935 Favorite Adjustable (Mannheim) 4055 (1927) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) E 4, 4W 4085-B, 4185-B, 4185-1, 68-2230       4620
4055 1936, 1937, 1939, 1942, 1943 Favorite Adjustable (Mannheim) (O'Leary collection) 4055 (1936) Improved Glass Indicator engine divided celluloid laminated mahogany A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230       4147
4056 1900, 1901, 1903, 1906 Favorite (Mannheim), polished Boxwood 4056 (1900) Brass Indicator Engine divided celluloid laminated mahogany A = B C = D =S L T = K&E conversion table   Closed Frame   25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341 4148
4056 1909, 1913 Favorite (Mannheim), polished Boxwood 4056 (1909) Metal Indicator Engine divided celluloid laminated mahogany A = B C = D =S L T = K&E conversion table   Closed Frame   25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341 4149
4056 1915, 1921, 1922, 1925 Favorite (Mannheim), polished Boxwood, listed as discontinued in the 1925 pricelist 4056 (1915) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D =S L T = K&E conversion table   Closed Frame   25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341 4150
4056 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Favorite (Mannheim), Listed as Temporarily Discontinued in 1952 Pricelist 4056 (1936) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D =S L T = NBS Circular 47 conversion table plain case Closed Frame   25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341 4151
National Union Radio Unknown National Union Radio, specialty scales for radio engineering (O'Leary Collection) 4058 (1950?) Glass Indicator with Metal Frame Light colored wood 4 - Impedence in Ohms = 3 - Frequency in cycles per second 2 - Inductance in Henrys = 1 - Capacitance in Farads Frequency scale (1c-20kc) Frequency scale (20kc-20mc) Directions to find capacitive reactance, inductive reactance, resonant frequency, and universal resonance curve   Closed Frame                   4628
4058 1900, 1901, 1903 Student's Slide Rule, (Mannheim), with white paper facing 4058 (1906) Unknown type Light colored wood A = B C = D =S L T = K&E conversion table   Closed Frame   25cm (10 inch)               4685
4058 1906, 1909, 1913 Student's Slide Rule, (Mannheim), with white paper facing 4058 (1906) Transparent Xylonite Indicator with metal frame Light colored wood A = B C = D =S L T = K&E conversion table   Closed Frame   25cm (10 inch)               4152
4058 1915, 1921, 1922 Student's Slide Rule, printed on light-colored wood 4058 (1915) Transparent Xylonite Indicator, with steel spring Light colored wood A = B C = D =S L T = K&E conversion table   Closed Frame   25cm (10 inch) M3             4153
4058 1925 Beginner's Slide Rule, printed on light-colored wood 4058 (1925) Transparent Xylonite Indicator, with steel spring Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) M3             4154
4058 1927, 1928, 1930, 1934, 1936, 1937, 1939 Beginner's Slide Rule, printed on light-colored wood 4058 (1927) Transparent Xylonite Indicator Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) M3             4156
4058W 1929, 1930 Beginners' Slide Rule, graduations on heavy white finish 4058 (1929) Frameless glass indicator with wooden indicator bars Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) M2             4158
4058W 1934 Beginners' Slide Rule, similar to N4058C, but with heavy white finish 4058 (1934) Frameless glass indicator with wooden indicator bars Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) M2             4508
4058W 1936, 1937, 1939 Beginners' Slide Rule 4058 (1936) Plain frame glass indicator Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table plain case Closed Frame   25cm (10 inch) M2       HH, 68-2279     4159
8858 1942 Special wartime issue, meant to be traded in for better slide rule 4058 (1942) Plain frame glass indicator Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table   Closed Frame   25cm (10 inch) M2       HH, 68-2279     4160
4058W 1942, 1943 Beginners' Slide Rule 4058 (1942) Glass Indicator with Metal Frame Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table leatheret sheath Closed Frame   25cm (10 inch) M2       HH, 68-2279     4161
N4058W 1944, 1947, 1949 Beginners' Slide Rule 4058 (1944) Glass Indicator with Metal Frame Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table sheath Closed Frame   25cm (10 inch) M2, M5, 99-6810       HH, 68-2279     4162
N4058W 1952, 1954, 1955 Beginners' Slide Rule 4058 (1952) Unbreakable Indicator Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table sheath Closed Frame   25cm (10 inch) M5, 99-6810       HH, 68-2279     4163
N4058C 1925, 1927, 1928, 1934 Beginners' Slide Rule, printed on light-colored wood 4058C (1925) Frameless glass indicator with wooden indicator bars Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table black covered box with gilt imprint Closed Frame   25cm (10 inch) M       HH, 68-2279     4155
4058C 1930, 1936, 1937, 1939 Beginners' Slide Rule, printed on light-colored wood 4058C (1930) Frameless glass indicator with wooden indicator bars Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table Two part hardcase with gold lettering Closed Frame   25cm (10 inch) M1, M4             4157
4058D 1942 Beginners' Slide Rule, printed on white finish 4058D (1942) Transparent Xylonite Indicator Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table Two part hardcase with gold lettering Closed Frame   25cm (10 inch) M1, M4             4536
4059 1939 Beginner's Slide Rule 4059 (1939) Transparent Xylonite Indicator Light colored wood A = B C = D =S L T = NBS Circular 47 conversion table in folding carton Closed Frame   20cm (8 inch) M3             4164
4060 1900, 1901, 1903 Duplex, with arithmetical slide (Rueb Collection) 4060 (1903) Brass Indicator Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D "Keuffel & Esser Co. N.Y." between 1 and 2 under the D scale Sewed Leather Case Duplex   12.5cm (5 inch)               4642
4060 1906 Duplex, with arithmetical slide (Rueb Collection) 4060 (1906) Metal Indicator Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D "Keuffel & Esser Co. N.Y." between 2 and 3 under the D scale Sewed Leather Case Duplex   12.5cm (5 inch)               4165
4061 1906, 1909, 1913 Duplex 4061 (1906) Glass Indicator with Metal Frame "Clamshell Indicator" Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Sewed Leather Case Duplex   12.5cm (5 inch)               4166
4061 1915 Duplex 4061 (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Sewed Leather Case Duplex   12.5cm (5 inch)               4645
4061 1916 Duplex 4061 (1916) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Sewed Leather Case Duplex   12.5cm (5 inch)               4167
4061T 1909, 1913 Duplex, with Trig Scales 4061T (1909) Glass Indicator with Metal Frame "Clamshell Indicator" Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L . Sewed Leather Case Duplex   12.5cm (5 inch)               4168
4061T 1915 Duplex, with Trig Scales 4061T (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L . Sewed Leather Case Duplex   12.5cm (5 inch)               4644
4061T 1916 Duplex, with Trig Scales 4061T (1916) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L . Sewed Leather Case Duplex   12.5cm (5 inch)               4169
4065 1900? Interchangeable Slides 4065 (1900) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   12.5cm (5 inch)               4170
4065N 1906 Duplex with trig scales 4065 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . . Sewed Leather Case Duplex   12.5cm (5 inch)               4171
4065 1909, 1913 Duplex 4065 (1909) Glass Indicator with Metal Frame "Clamshell Indicator" Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D .   Duplex   20cm (8 inch)               4172
4065 1914 Duplex 4065 (1914) Frameless Glass Indicator with columnar indicator Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Sewed Leather Case Duplex   20cm (8 inch)               4692
4065 1915 Duplex 4065 (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Sewed Leather Case Duplex   20cm (8 inch)               4173
4065T 1909, 1913 Duplex Trig 4065T (1909) Glass Indicator with Metal Frame "Clamshell Indicator" Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L . Sewed Leather Case Duplex   20cm (8 inch)               4174
4065T 1914 Duplex Trig 4065T (1914) Frameless Glass Indicator with columnar indicator Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L . Sewed Leather Case Duplex   20cm (8 inch)               4693
4065T 1915 Duplex Trig 4065T (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L . Sewed Leather Case Duplex   20cm (8 inch)               4175
4065T 1916? Duplex Trig 4065T (1916?) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D L . Sewed Leather Case Duplex   20cm (8 inch)               4501
4066 1900? Interchangeable Slides 4066 (1900) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . .   Duplex   12.5cm (5 inch)               4176
4066N 1906 Duplex with trig scales 4066 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . . Sewed Leather Case Duplex   12.5cm (5 inch)               4177
4067 1906 Duplex 4067 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . . Sewed Leather Case Duplex   20cm (8 inch)               4178
4068 1906 Duplex 4068 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . . Sewed Leather Case Duplex   20cm (8 inch)               4179
4069 1906 Duplex with trig scales 4069 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . . Sewed Leather Case Duplex   20cm (8 inch)               4180
4069 1/2 1906 Duplex with trig scales 4069.5 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . . Sewed Leather Case Duplex   20cm (8 inch)               4181
4070 1906 Duplex 4070 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   25cm (10 inch)               4182
4070 1915 Duplex 4070 (1915) Frameless glass indicator, with metal indicator bars Engine divided celluloid laminated mahogany . . .   Duplex   25cm (10 inch)               4183
4070T 1915 Duplex with trig scales 4070 (1915) Frameless glass indicator, with metal indicator bars Engine divided celluloid laminated mahogany . . .   Duplex   25cm (10 inch)               4648
4070-3 1939 Polyphase Duplex Trig (Pat. 1,930,852 Pat. Pend.) 4070 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4184
4070-3S 1939 Polyphase Duplex Trig (Pat. 1,930,852 Pat. Pend.) 4070 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI . Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4185
4070-3 1942, 1943, 1944, 1947, 1949, 1952, 1954 Polyphase Duplex Trig (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.) 4070 (1942) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4562
4070-3S 1942, 1943, 1944, 1947, 1949, 1952, 1954 Polyphase Duplex Trig (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.) 4070 (1942) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI . Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4563
4070-3 1955 Polyphase Duplex Trig (O'Leary Collection) 4070 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T ST S = D DI (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.)   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4566
4070-3S 1955 Polyphase Duplex Trig 4070 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T ST S = D DI (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.) Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4567
68-1524 1962 Polyphase Duplex Trig 4070 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4186
68-1529 1962 Polyphase Duplex Trig 4070 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4187
4071 1906 Duplex 4071 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D .   Duplex   25cm (10 inch)               4639
4071 1909, 1913 Duplex 4071 (1909) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D .   Duplex   25cm (10 inch)               4188
4071 1915 Duplex 4071 (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Morocco Case Duplex   25cm (10 inch)               4189
4071-3 1939 Polyphase Duplex Decitrig (Pat. 1,930,852 Pat. Pend.) 4071 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 113
4071-3S 1939 Polyphase Duplex Decitrig (Pat. 1,930,852 Pat. Pend.) 4071 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI . Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4191
4071-3 1942, 1943, 1944, 1947, 1949, 1952, 1954 Polyphase Duplex Decitrig (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.) 4071 (1942) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4564
4071-3S 1942, 1943, 1944, 1947, 1949, 1952, 1954 Polyphase Duplex Decitrig (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.) 4071 (1942) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L K A = B T ST S = D DI . Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4565
9071-3 1949 DORIC 4071 (1949) Improved Glass Indicator Engine Divided White Xylonite DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) SL 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4192
9071-3S 1949 DORIC 4071 (1949) Improved Glass Indicator Engine Divided White Xylonite DF = CF CIF CI C = D L K A = B T ST S = D DI . Sewed Leather Case Duplex   25cm (10 inch) SL 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4193
4071-3 1955 Polyphase Duplex Decitrig (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.) 4071 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4568
4071-3S 1955 Polyphase Duplex Decitrig (Pats. 1,930,852 2,168,056 2,170,144 Pat. Pend.) 4071 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T ST S = D DI . Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4569
4071-3 1955 (Sept.) Polyphase Duplex Decitrig 4071 (1955, Sept.) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T SRT S = D DI Inlaid celluloid with mahogany on edges   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4558
4071-3S 1955 (Sept.) Polyphase Duplex Decitrig (O'Leary Collection) 4071 (1955, Sept.) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T SRT S = D DI Inlaid celluloid with mahogany on edges Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4559
68-1497 1962, 1967 Polyphase Duplex Decitrig 4071 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T SRT S = D DI . Sewed Leather Case, chamois lined Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4194
68-1502 1962, 1967 Polyphase Duplex Decitrig 4071 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany strips on edge DF = CF CIF CI C = D L K A = B T SRT S = D DI . Synthetic Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4195
4071T 1909 Duplex, with Trig Scales (Otnes Collection) 4071T (1909) Glass Indicator with clamshell style frame Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L Indicator has an indicator mark on split top for L scale readings on top edge   Duplex   25cm (10 inch)               4196
4071T 1913 Duplex, with Trig Scales (Otnes Collection) {L scale on back, not edge} 4071T (1913) Glass Indicator with column style indicator frame Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L .   Duplex   25cm (10 inch)               4499
4071T 1914 Duplex, with Trig Scales (Otnes Collection) {L scale on back, not edge} 4071T (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D L .   Duplex   25cm (10 inch)               4546
4071T 1915 Duplex, with Trig Scales 4071T (1915) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L . Sewed Leather Case Duplex   25cm (10 inch)               4197
4071T 1915 Duplex, with Trig Scales (from Clark McCoy's collection) {L scale on back, not edge} 4071T (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D L .   Duplex   25cm (10 inch)               4547
4075 1900? Duplex, Interchangeable Slides 4075 (1900) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   25cm (10 inch)               4198
4075N 1906 Duplex with trig scales 4075 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   25cm (10 inch)               4199
4076 1900 Duplex, Interchangeable Slides 4076 (1900) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . .   Duplex   25cm (10 inch)               4200
4076N 1906 Duplex with trig scales 4076 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . .   Duplex   25cm (10 inch)               4201
4078 1900? Duplex 4078 (1900) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   50cm (20 inch)               4202
4079 1900? Duplex 4079 (1900) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . .   Duplex   50cm (20 inch)               4203
4080 1903? Interchangeable Slides 4080 (1900) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   50cm (20 inch)               4204
N105 1952, 1954, 1955 Demonstration Slide Rule, with device for suspending and turning over. For use with 4080, 4081, 4181 4080 (1954) Frameless plastic indicator with wooden indicator bars Wood, Composition unspecified LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 .   Duplex   8 Feet               4205
4080-3 1937 Log Log Duplex Trig 4080-3 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL00 LL0 A = B T ST S = D DI K Replaced 4090-3   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4206
4080-3 1937 Log Log Duplex Trig (McCoy Collection) 4080-3 (1937) Improved Glass Indicator, marked "patent pending" Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL00 LL0 A = B T ST S = D DI K Replaced 4090-3. Has Keuffel & Esser Co. in a circle on upper right stator.   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4629
4080-3S 1937 Log Log Duplex Trig 4080-3 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL00 LL0 A = B T ST S = D DI K Replaced 4090-3S Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4207
4080-3 1939, 1942, 1943 Log Log Duplex Trig 4080-3 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Major scale change. Beware of KERCS   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4208
4080-3S 1939, 1942, 1943 Log Log Duplex Trig 4080-3 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Major scale change. Beware of KERCS Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4209
4080-3 1944, 1947 Log Log Duplex Trig 4080-3 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Introduction of "K+E" stylized logo on right front of slide   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4618
4080-3S 1944, 1947 Log Log Duplex Trig 4080-3 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Introduction of "K+E" stylized logo on right front of slide Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4619
N4080-3 1949, 1952 Log Log Duplex Trig 4080-3 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 New scale set, and the addition of the "N" to the model number.   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4210
N4080-3S 1949, 1952 Log Log Duplex Trig 4080-3 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 New scale set, and the addition of the "N" to the model number. Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4211
N4080-3 1952 Log Log Duplex Trig 4080-3 (1952) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 Exposed mahogany edges added, model number on the top edge   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4632
N4080-3S 1952 Log Log Duplex Trig 4080-3 (1952) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 Exposed mahogany edges added, model number on the top edge Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4633
4080-3 1953, 1954, 1955 Log Log Duplex Trig 4080-3 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 DI scale added   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4212
4080-3S 1953, 1954, 1955 Log Log Duplex Trig 4080-3 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 DI scale added Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4213
4080-3 1958 (?) Log Log Duplex Trig (suspected to exist) 4080-3 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 Rivets on lower stator replaced with hex screws   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4607
4080-3S 1958 (?) Log Log Duplex Trig (suspected to exist) 4080-3 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 Rivets on lower stator replaced with hex screws Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4608
68-1318 1962, 1967 Log Log Duplex Trig 4080-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 . Sewed Leather Case, chamois lined Duplex   25cm (10 inch) IW, 68-2118 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4214
68-1323 1962, 1967 Log Log Duplex Trig 4080-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 . Synthetic Leather Case Duplex   25cm (10 inch) IW, 68-2118 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4215
4080-5 1939, 1942, 1943, 1944, 1947 Log Log Duplex Trig 4080-5 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4367
4080-5S 1939, 1942, 1943, 1944, 1947 Log Log Duplex Trig 4080-5 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4217
N4080-5 1949, 1952 Log Log Duplex Trig 4080-5 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4218
N4080-5S 1949, 1952 Log Log Duplex Trig 4080-5 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4219
4080-5 1953, 1954, 1955 Log Log Duplex Trig 4080-5 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4220
4080-5S 1953, 1954, 1955 Log Log Duplex Trig 4080-5 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4221
4080-5 1958 (?) Log Log Duplex Trig (suspected to exist) 4080-5 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 Rivets on lower stator replaced with hex screws   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4611
4080-5S 1958 (?) Log Log Duplex Trig (suspected to exist) 4080-5 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 Rivets on lower stator replaced with hex screws Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4612
68-1308 1962 Log Log Duplex Trig 4080-5 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 . Sewed Leather Case, chamois lined Duplex   50cm (20 inch) IaW, 68-2115 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4222
68-1313 1962 Log Log Duplex Trig 4080-5 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 . Synthetic Leather Case Duplex   50cm (20 inch) IaW, 68-2115 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4223
4081-3 1937 Log Log Decitrig Duplex (O'Leary Collection) 4081-3 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL00 LL0 A = B T ST S = D DI K Replaced 4091-3   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4235
4081-3S 1937 Log Log Decitrig Duplex (O'Leary Collection) 4081-3 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL00 LL0 A = B T ST S = D DI K Replaced 4091-3S Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4236
4081-3 1939 Log Log Duplex Decitrig (McCoy Collection) 4081-3 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Major scale change. Beware of KERCS. The printing of "KEUFFEL&ESSER CO NY" is above the .1 on the L scale   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4616
4081-3S 1939 Log Log Duplex Decitrig (McCoy Collection) (O'Leary Collection) 4081-3 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Major scale change. Beware of KERCS. The printing of "KEUFFEL&ESSER CO NY" is above the .1 on the L scale Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4617
4081-3 1940, 1942, 1943, 1944 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1940) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K The printing of "KEUFFEL&ESSER CO NY" was moved from the .2 on the L scale to .1 on the L scale Hardcase with card flap and snap Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4237
4081-3S 1940, 1942, 1943, 1944 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1940) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K The printing of "KEUFFEL&ESSER CO NY" was moved from the .2 on the L scale to .1 on the L scale Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4238
4081-3 1944 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Introduction of "K+E" stylized logo on right front of slide   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4597
4081-3S 1944 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K Introduction of "K+E" stylized logo on right front of slide Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4598
4081-3 1947 Log Log Duplex Decitrig 4081-3 (1947) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 Major scale change   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4599
4081-3S 1947 Log Log Duplex Decitrig 4081-3 (1947) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 Major scale change Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4600
N4081-3 1948 ? Log Log Duplex Decitrig 4081-3 (1948) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 "N" added to model number, model number and 4 patents and Patent Pending on the top edge   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4646
N4081-3S 1948 ? Log Log Duplex Decitrig 4081-3 (1948) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 "N" added to model number, model number and 4 patents and Patent Pending on the top edge Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4647
4081-3 Braille Unknown Log Log Duplex Decitrig, Braille on both sides, from the collection of Jack Burton, VP Mktg, K&E 4081-3 (1949) Unknown . . . .   Unknown   .               4224
N4081-3 1949 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 "N" added to model number, model number and 5 patents on the top edge   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4239
N4081-3S 1949 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 "N" added to model number, model number and 5 patents on the top edge Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4240
N4081-3 1952 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1952) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 Exposed mahogany edges added, model number and 5 patents on the top edge   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4601
N4081-3S 1952 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1952) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 Exposed mahogany edges added, model number and 5 patents on the top edge Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4602
4081-3 1953, 1954, 1955 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 DI scale added   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4243
4081-3S 1953, 1954, 1955 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 DI scale added Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4244
4081-3 1955 (Sept.) Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 "SRT" scale added   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4552
4081-3S 1955 (Sept.) Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 "SRT" scale added Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4553
4081-3 1959 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1959) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Rivets on lower stator replaced with hex screws   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4605
4081-3S 1959 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1959) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Rivets on lower stator replaced with hex screws Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4606
E4081 1960 Log Log Duplex Decitrig 4081-3 (1960) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . Sewed Leather Case, chamois lined, with belt carrier Duplex   25cm (10 inch) RW, 68-2121 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4246
68-1210 1962, 1967, 1972 Log Log Duplex Decitrig 4081-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Renumbered to 68-xxxx series, rivets on lower stator replaced with hex screws Sewed Leather Case, chamois lined, with belt carrier Duplex   25cm (10 inch) IW, 68-2118 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4248
68-1215 1962, 1967, 1972 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Renumbered to 68-xxxx series, rivets on lower stator replaced with hex screws Sewed Leather Case, chamois lined Duplex   25cm (10 inch) IW, 68-2118 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4249
68-1220 1962, 1967 Log Log Duplex Decitrig (O'Leary Collection) 4081-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Renumbered to 68-xxxx series, rivets on lower stator replaced with hex screws Synthetic Leather Case Duplex   25cm (10 inch) IW, 68-2118 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4250
68-1923 1962, 1967 Demonstration rule, for use with 4081, 4181 family of rules 4081-3 (1962) Frameless plastic indicator with wooden indicator bars redwood LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 .   Duplex   8 Feet               4225
68-1950 1962, 1967 Trunnions (2) for mounting of Deci-Lon and Decitrig Demonstration Rules 4081-3 (1962) . steel . . .   Duplex   .               4226
68-1960 1967 Jet-Log Projection Slide Rule 4081-3 (1967) Clear plastic mounted on oversize frameless indicator bars clear "eye-ease" green unbreakable plastic, with red and black numbers Upper (frontview) LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Lower (Backview) LL01 L K A = B T SRT S = D DI LL1 . . plush-lined leatherette covered case Duplex   .               4227
4081-5 1939, 1942, 1943, 1944, 1947 Log Log Duplex Decitrig 4081-5 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4253
4081-5S 1939, 1942, 1943, 1944, 1947 Log Log Duplex Decitrig 4081-5 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D DI K . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4254
N4081-5 1949, 1952 Log Log Decitrig Duplex 4081-5 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4255
N4081-5S 1949, 1952 Log Log Decitrig Duplex 4081-5 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4256
4081-5 1953, 1954, 1955 Log Log Duplex Decitrig 4081-5 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4257
4081-5S 1953, 1954, 1955 Log Log Duplex Decitrig 4081-5 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4258
4081-5 1955 (Sept.) Log Log Duplex Decitrig 4081-5 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4190
4081-5S 1955 (Sept.) Log Log Duplex Decitrig 4081-5 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4216
4081-5 1958 (?) Log Log Duplex Decitrig (suspected to exist) 4081-5 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Rivets on lower stator replaced with hex screws   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4609
4081-5S 1958 (?) Log Log Duplex Decitrig (suspected to exist) 4081-5 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Rivets on lower stator replaced with hex screws Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4610
68-1200 1962, 1967 Decitrig 4081-5 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . Sewed Leather Case, chamois lined Duplex   50cm (20 inch) IaW, 68-2115 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4259
68-1205 1962, 1967 Decitrig 4081-5 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . Synthetic Leather Case Duplex   50cm (20 inch) IaW, 68-2115 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4260
4082 1906 Duplex 4082 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   42cm (16 inch)               4261
4082-3 1937 "Special Radio", a precursor to 4139 Cooke Radio Rule. It has the 4081 scaleset with an inverted 1/2pi(x) scale (F) in place of K scale. Collection of Bob De Cesaris. 4082-3 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL00 LL0 A = B T ST S = D DI F This slide rule has Log Log scales, where the 4139 does not. These greatly assist in the tracking of the decimal point in LC calculations. Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4555
4082-3 1939 Log Log Duplex Decitrig Slide Rule With F Scale, sold simultaneously with the 4139 Cooke Radio Rule. It has the 4081 scaleset with 1/2pi(x) scale (F) in place of K scale 4082-3 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LLO LLOO A = B T ST S = D DI F This slide rule has Log Log scales, where the 4139 does not. These greatly assist in the tracking of the decimal point in LC calculations. Rules in the collections of Clark McCoy and Michael O'Leary Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4262
4083 1906, 1909 Duplex 4083 (1909) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D .   Duplex   42cm (16 inch)               4263
4083 1913 Duplex 4083 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Morocco Case Duplex   42cm (16 inch)               4264
4083 1915 Duplex 4083 (1915) Frameless glass indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Morocco Case Duplex   42cm (16 inch)               4265
4083T 1915 Duplex, with Trig Scales 4083 (1915) Frameless glass indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Morocco Case Duplex   42cm (16 inch)               4649
4083-3 1939, 1942, 1943, 1944 Log Log Duplex Vector (O'Leary Collection) 4083-3 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D Th Sh2 Sh1 Replaced 4093-3, Beware of KERCS   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4266
4083-3S 1939, 1942, 1943, 1944 Log Log Duplex Vector (O'Leary Collection) 4083-3 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D Th Sh2 Sh1 Replaced 4093-3S, Beware of KERCS Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4267
4083-3 1947 Log Log Duplex Vector 4083-3 (1947) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 Major scale change Hardcase with card flap and snap Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4268
4083-3S 1947 Log Log Duplex Vector 4083-3 (1947) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 Major scale change Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4590
N4083-3 1949, 1952 Log Log Duplex Vector (O'Leary Collection) 4083-3 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 "N" added to model number   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4269
N4083-3S 1949, 1952 Log Log Duplex Vector (O'Leary Collection) 4083-3 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 "N" added to model number Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4270
N4083-3 1953 Log Log Duplex Vector (O'Leary Collection) 4083-3 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 DI scale added, exposed mahogany edges added   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4588
N4083-3S 1953 Log Log Duplex Vector (O'Leary Collection) 4083-3 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 DI scale added, exposed mahogany edges added Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4589
4083-3 1954, 1955 Log Log Duplex Vector 4083-3 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 "N" removed from model number   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4271
4083-3S 1954, 1955 Log Log Duplex Vector 4083-3 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 "N" removed from model number Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4272
4083-3 1955 (Sept.) Log Log Duplex Vector (O'Leary & McCoy Collections) 4083-3 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 "SRT" scale added   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4502
4083-3S 1955 (Sept.) Log Log Duplex Vector (O'Leary & McCoy Collections) 4083-3 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 "SRT" scale added Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4503
4083-3 1958 (?) Log Log Duplex Vector (O'Leary Collection) 4083-3 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Rivets on lower stator replaced with hex screws   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4570
4083-3S 1958 (?) Log Log Duplex Vector (O'Leary Collection) 4083-3 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Rivets on lower stator replaced with hex screws Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4571
68-1434 1962, 1967 Log Log Duplex Vector 4083-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Renumbered to 68-xxxx series Sewed Leather Case, chamois lined Duplex   25cm (10 inch) IW, 68-2118 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4273
68-1439 1962, 1967 Log Log Duplex Vector (O'Leary Collection) 4083-3 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Renumbered to 68-xxxx series Synthetic Leather Case Duplex   25cm (10 inch) IW, 68-2118 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4274
4083-5 1939, 1942, 1943, 1944, 1947 Log Log Duplex Vector 4083-5 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D Th Sh2 Sh1 Replaced 4093-5, Beware of KERCS   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4275
4083-5S 1939, 1942, 1943, 1944, 1947 Log Log Duplex Vector 4083-5 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 LL00 A = B T ST S = D Th Sh2 Sh1 Replaced 4093-5S, Beware of KERCS Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4276
4083-5 1947 Log Log Duplex Vector 4083-5 (1947) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 Major scale change   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4591
4083-5S 1947 Log Log Duplex Vector 4083-5 (1947) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 Major scale change Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4592
N4083-5 1949, 1952 Log Log Vector 4083-5 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 "N" added to model number   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4277
N4083-5S 1949, 1952 Log Log Vector 4083-5 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany LL02 LL03 DF = CF CIF CI C = D LL3 LL2 L LL01 LL1 A = B T ST S = D Th Sh2 Sh1 "N" added to model number Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4278
N4083-5 1953 Log Log Vector 4083-5 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 DI scale added, exposed mahogany edges added   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4593
N4083-5S 1953 Log Log Vector 4083-5 (1953) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 DI scale added, exposed mahogany edges added Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4594
4083-5 1954, 1955 Log Log Duplex Vector 4083-5 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 "N" removed from model number   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4279
4083-5S 1954, 1955 Log Log Duplex Vector 4083-5 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T ST S = D DI LL01 LL1 "N" removed from model number Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4280
4083-5 1955 (Sept.) Log Log Duplex Vector 4083-5 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 "SRT" scale added   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4595
4083-5S 1955 (Sept.) Log Log Duplex Vector 4083-5 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 "SRT" scale added Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4596
4083-5 1958 (?) Log Log Duplex Vector (suspected to exist) 4083-5 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Rivets on lower stator replaced with hex screws   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4613
4083-5S 1958 (?) Log Log Duplex Vector (suspected to exist) 4083-5 (1958) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Rivets on lower stator replaced with hex screws Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4614
68-1424 1962 Log Log Duplex Vector 4083-5 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Renumbered to 68-xxxx series   Duplex   50cm (20 inch) IaW, 68-2115 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4281
68-1429 1962 Log Log Duplex Vector 4083-5 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany, with exposed mahogany edges LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Sh1 Sh2 Th A = B T SRT S = D DI LL01 LL1 Renumbered to 68-xxxx series   Duplex   50cm (20 inch) IaW, 68-2115 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4282
4083T 1909, 1913 Duplex, with Trig Scales 4083T (1909) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L .   Duplex   42cm (16 inch)               4283
4083T 1914 Duplex, with Trig Scales 4083T (1914) Glass Indicator with column style indicator frame Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L .   Duplex   42cm (16 inch)               4631
4083T 1915 Duplex, with Trig Scales 4083T (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L .   Duplex   42cm (16 inch)               4284
4084 1906 Duplex with trig scales 4084 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   42cm (16 inch)               4285
4085 1906 Duplex with trig scales 4085 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . .   Duplex   42cm (16 inch)               4286
4086 1906 Duplex 4086 (1906) Metal Indicator Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D .   Duplex   50cm (20 inch)               4287
4087 1906, 1909 Duplex 4087 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D .   Duplex   50cm (20 inch)               4288
4087 1913 Duplex 4087 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Morocco Case Duplex   50cm (20 inch)               4289
4087 1914 Duplex (Schure Collection) 4087 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . . Duplex   50cm (20 inch)               4636
4087 1915 Duplex 4087 (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Morocco Case Duplex   50cm (20 inch)               4290
4087 1916 Duplex (suspected to exist) 4087 (1916) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B C = D A = BI CI = D . Morocco Case Duplex   50cm (20 inch)               4557
4087T 1909, 1913 Duplex, with Trig Scales 4087T (1909) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L .   Duplex   50cm (20 inch)               4291
4087T 1915 Duplex, with Trig Scales 4087T (1915) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D ] L .   Duplex   50cm (20 inch)               4292
4087T 1916 Duplex, with Trig Scales. Collection of Dave Rueb 4087T (1916) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B S C = D A = BI T CI = D L L scale moved from bottom edge to back of rule   Duplex   50cm (20 inch)               4556
4088 1906 Duplex with trig scales 4088 (1906) Metal Indicator Engine divided celluloid laminated mahogany . . .   Duplex   50cm (20 inch)               4293
4088-1S 1922, 1925 Polyphase Duplex 4088-1 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Sheath Duplex   12.5cm (5 inch) K, 99-6807 8W, 99-6820       U   4296
4088-1S 1927, 1928, 1930, 1934, 1936, 1937, 1939 Polyphase Duplex 4088-1 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case without flap Duplex   12.5cm (5 inch) K, 99-6807 8W, 99-6820       U   4298
4088-2 1913 Polyphase Duplex 4088-2 (1913) Glass Indicator with column style indicator frame Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   20cm (8 inch)     4085-B, 4185-B, 4185-1, 68-2230     V VM 4294
4088-2 1914 Polyphase Duplex (suspected to exist) 4088-2 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = S T CI = D L . Sewed Leather Case Duplex   20cm (8 inch) GL, 99-6809 6L, 99-6819 4085-B, 4185-B, 4185-1, 68-2230     V VM 4528
4088-2 1915, 1921 Polyphase Duplex 4088-2 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = S T CI = D L . Sewed Leather Case Duplex   20cm (8 inch) G   4085-B, 4185-B, 4185-1, 68-2230     V VM 4295
4088-2S 1922, 1925, 1927, 1928, 1930, 1934 Polyphase Duplex 4088-2 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   20cm (8 inch) G   4085-B, 4185-B, 4185-1, 68-2230     V VM 4297
4088-2S 1936, 1937, 1939 Polyphase Duplex 4088-2 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   20cm (8 inch) GL, 99-6809 6L, 99-6819 4085-B, 4185-B, 4185-1, 68-2230     V VM 4299
4088-3 1913 Polyphase Duplex (Otnes Collection) 4088-3 (1913) Glass Indicator with column style indicator frame Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = S T CI = D L . Sewed Leather Case Duplex   25cm (10 inch)     4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4300
4088-3S 1914 Polyphase Duplex (O'Leary Collection) 4088-3 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = S T CI = D L .   Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4529
4088-3 1915, 1921 Polyphase Duplex 4088-3 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = S T CI = D L .   Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4301
4088-3 1922, 1925, 1927, 1928, 1930, 1934 Polyphase Duplex 4088-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L .   Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4302
4088-3S 1922, 1925, 1927, 1928, 1930, 1934 Polyphase Duplex 4088-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4303
4088-3 1935 Polyphase Duplex 4088-3 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L .   Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4626
4088-3S 1935 Polyphase Duplex (O'Leary Collection) 4088-3 (1935) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4627
4088-3 1936, 1937, 1939 Polyphase Duplex, listed as discontinued in the 1939 pricelist, supplanted by 4070-3 4088-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L .   Duplex   25cm (10 inch) GL, 99-6809 6L, 99-6819 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4304
4088-3S 1936, 1937, 1939 Polyphase Duplex, listed as discontinued in the 1939 pricelist, supplanted by 4070-3S 4088-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   25cm (10 inch) GL, 99-6809 6L, 99-6819 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4305
4088-5 1921 Polyphase Duplex 4088-5 (1921) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = S T CI = D L .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4306
4088-5 1922, 1925, 1927, 1928, 1930, 1934 Polyphase Duplex 4088-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4307
4088-5S 1922, 1925, 1927, 1928, 1930, 1934 Polyphase Duplex 4088-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4308
N4088-5 1936, 1937, 1939 Polyphase Duplex, listed as discontinued in the 1939 pricelist (Cerny Collection) 4088-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L .   Duplex   50cm (20 inch) IL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4309
N4088-5S 1936, 1937, 1939 Polyphase Duplex, listed as discontinued in the 1939 pricelist 4088-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CIF C = D K A = B S T CI = D L . Sewed Leather Case Duplex   50cm (20 inch) IL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4310
4089 1906 Duplex with trig scales 4089 (1906) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany . . .   Duplex   50cm (20 inch)               4311
4090 1899 Universal, 2 attached slides (Prototype #1 in Otnes Collection) 4090 (1899) None Engine divided hardwood A = B C = D (DF - unmarked) = C (folded) S = A A = BI CI = D (DF - unmarked) = CI (folded) L T = D Original prototype for 4090 Universal rule   Duplex, with two slides joined   25cm (10 inch)               4621
4090 1899 Universal, 2 attached slides (Prototype #2 in Otnes Collection) 4090 (1899) None Engine divided celluloid laminated mahogany A = B C = D (DF - unmarked) = C (folded) S = A A = BI CI = D (DF - unmarked) = CI (folded) L T = D Original prototype for 4090 Universal rule   Duplex, with two slides joined   25cm (10 inch)               4622
4090 1900?? Universal, 2 attached slides 4090 (1900) Metal Indicator . . . .   Duplex, with two slides joined   25cm (10 inch)               4312
4090 1901?, 1903? Universal, 2 attached slides (Schure Collection) 4090 (1901) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany A = B C = D (DF - unmarked) = C (folded) S = A A = BI CI = D (DF - unmarked) = CI (folded but not inverted) L T = D .   Duplex, with two slides joined   25cm (10 inch)               4313
4090N 1906 Universal, 2 attached slides 4090 (1909) German Silver Indicator that embraces the entire rule. . A = B C = D DF = CIF L T = D (folded scales folded at ~3.16) BI, CI, folded D scale, folded DI scale, L, T, D (order and position uncertain) .   Duplex, with two slides joined   25cm (10 inch)               4314
4090N 1909 Universal, 2 attached slides 4090 (1909) framed(?) Glass Indicator that embraces the entire rule. . A = B C = D DF = CIF L T = D (folded scales folded at ~3.16) BI, CI, folded D scale, folded DI scale, L, T, D (order and position uncertain) .   Duplex, with two slides joined   25cm (10 inch)               4315
4090-3 1934 Log Log Trig 4090 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 .   Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4538
4090-3S 1934 Log Log Trig 4090 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 . Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4539
4090-3 1936 Log Log Trig 4090 (1936) Improved Glass Indicator, marked Patent Pending Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 .   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4316
4090-3S 1936 Log Log Trig 4090 (1936) Improved Glass Indicator, marked Patent Pending Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 . Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4317
4090-3 1937, 1939 Log Log Trig, listed as discontinued in the 1937 pricelist, supplanted by 4080-3, listed as available in 1939 pricelist 4090 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 .   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4574
4090-3S 1937, 1939 Log Log Trig, listed as discontinued in the 1937 pricelist, supplanted by 4080-3S, listed as available in 1939 pricelist 4090 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 . Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4573
4091 1906 Universal, 2 attached slides 4091 (1906) German Silver Indicator that embraces the entire rule. . A = B C = D DF = CIF L T = D (folded scales folded at ~3.16) BI, CI, folded D scale, folded DI scale, L, T, D (order and position uncertain) .   Duplex, with two slides joined   42cm (16 inch)               4318
4091 1909 Universal, 2 attached slides 4091 (1906) framed(?) Glass Indicator that embraces the entire rule. . A = B C = D DF = CIF L T = D (folded scales folded at ~3.16) BI, CI, folded D scale, folded DI scale, L, T, D (order and position uncertain) .   Duplex, with two slides joined   42cm (16 inch)               4319
4091-3 1934 Log Log Decitrig 4091 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany L LL1 DF = CF CIF C = D LL3 LL2 LL0 A = B K CI = T S2 S1 .   Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4537
4091-3S 1934 Log Log Decitrig 4091 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany L LL1 DF = CF CIF C = D LL3 LL2 LL0 A = B K CI = T S2 S1 . Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4540
4091-3 1936 Log Log Decitrig 4091 (1936) Improved Glass Indicator, marked Patent Pending Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 .   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4320
4091-3S 1936 Log Log Decitrig 4091 (1936) Improved Glass Indicator, marked Patent Pending Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 . Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4321
4091-3 1937 Log Log Decitrig, special order with LC scale 4091 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LC LL0 A = B K CI = T S2 S1 Marked SPEC. <4091-3>   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4674
4091-3 1937, 1939 Log Log Decitrig, listed as discontinued in the 1937 & 1939 pricelists, supplanted by 4081-3 4091 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 .   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4575
4091-3S 1937, 1939 Log Log Decitrig, listed as discontinued in the 1937 & 1939 pricelists, supplanted by 4081-3S 4091 (1937) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL1 DF = CF CIF CI C = D LL3 LL2 LL0 A = B K CI = T S2 S1 . Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4576
4092 1909 Log Log Duplex 4092 (1909) Glass Indicator with Metal Frame "Clamshell Indicator" Engine divided celluloid laminated mahogany, with exposed mahogany edges A = B S C = D LL1 LL2 LL3 = C T CI = D L Serifed font for lettering   Duplex   25cm (10 inch)               4323
4092 1913 Log Log Duplex 4092 (1913) Glass Indicator with Metal Frame "Clamshell Indicator" Engine divided celluloid laminated mahogany, with exposed mahogany edges A = B S C = D LL1 LL2 LL3 = C T CI = D L Serifed font for lettering Morocco Case Duplex   25cm (10 inch)               4324
4092 1913 Log Log Duplex 4092 (1913) Glass Indicator with column style indicator frame Engine divided celluloid laminated mahogany, with exposed mahogany edges A = B S C = D LL1 LL2 LL3 = C T CI = D L Serifed font for lettering Morocco Case Duplex   25cm (10 inch)               4497
4092 1914 Log Log Duplex 4092 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany, with exposed mahogany edges A = B S C = D LL1 LL2 LL3 = C T CI = D L Serifed font for lettering   Duplex   25cm (10 inch) I, or complete replacement with IL/7L set             4500
4092 1914 Log Log Duplex 4092 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany, with exposed mahogany edges A = B S C = D LL1 LL2 LL3 = C T CI = L Serifed font for lettering. Referenced in "The Mannheim (Complete Manual) and the Duplex Slide Rules" Manual "E" 1914   Duplex   12.5cm (5 inch)               4322
4092 1915, 1921 Log Log Duplex 4092 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany, with exposed mahogany edges A = B S C = D LL1 LL2 LL3 = C T CI = D L Serifed font for lettering Morocco Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set             4325
4092-3 1922 Log Log Duplex (Reub Collection) 4092-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 Serifed font for lettering.   Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4326
4092-3S 1922 Log Log Duplex 4092-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 Serifed font for lettering. Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4327
N4092-3 1925, 1927, 1928, 1930 Log Log Duplex 4092-3 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 Serifed font for lettering. "N" does not appear in model number. Added "K" scale Hard case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4328
N4092-3S 1925, 1927, 1928, 1930 Log Log Duplex 4092-3 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 Serifed font for lettering. "N" does not appear in model number. Added "K" scale Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4329
N4092-3 1934 Log Log Duplex 4092-3 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 NON-serifed font for lettering. "N" does not appear in model number. Hard case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4542
N4092-3S 1934 Log Log Duplex (O'Leary Collection) 4092-3 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 NON-serifed font for lettering. "N" does not appear in model number. Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4541
4092-3 1936, 1937, 1939 Log Log Duplex, listed as discontinued in the 1939 pricelist, supplanted by 4080-3 to 4081-5S 4092-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 NON-serifed font for lettering. "N" does not appear in model number. Hard case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4330
4092-3S 1936, 1937, 1939 Log Log Duplex, listed as discontinued in the 1939 pricelist, supplanted by 4080-3 to 4081-5S 4092-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 NON-serifed font for lettering. "N" does not appear in model number. Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4331
4092-5 1922, 1925 Log Log Duplex 4092-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4185-8, 68-2221 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4332
4092-5S 1922, 1925 Log Log Duplex 4092-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4333
N4092-5 1927, 1928, 1930 Log Log Duplex 4092-5 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4515
N4092-5S 1927, 1928, 1930 Log Log Duplex 4092-5 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4496
N4092-5 1936, 1937, 1939 Log Log Duplex, listed as discontinued in the 1939 pricelist, supplanted by 4080-3 to 4081-5S 4092-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4334
N4092-5S 1936, 1937, 1939 Log Log Duplex, listed as discontinued in the 1939 pricelist, supplanted by 4080-3 to 4081-5S 4092-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany K DF = CF CIF CI C = D L LL0 A = B S T C = LL3 LL2 LL1 . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4335
4093-3 1929, 1930 Log Log Vector (O'Leary Collection) 4093-3 (1929) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T .   Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4336
4093-3S 1929, 1930 Log Log Vector 4093-3 (1929) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T . Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4337
4093-3 1934 Log Log Vector (suspected to exist) 4093-3 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T .   Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4543
4093-3S 1934 Log Log Vector (suspected to exist) 4093-3 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T . Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4544
4093-3 1936, 1937, 1939 Log Log Vector, listed as discontinued in the 1939 pricelist, supplanted by 4083-3 4093-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T .   Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4338
4093-3S 1936, 1937, 1939 Log Log Vector, listed as discontinued in the 1939 pricelist, supplanted by 4083-3S (O'Leary Collection) 4093-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T . Sewed Leather Case Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4339
4093-5 1934 Log Log Vector 4093-5 (1934) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4512
4093-5S 1934 Log Log Vector 4093-5 (1934) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4513
4093-5 1936, 1937, 1939 Log Log Vector, listed as discontinued in the 1939 pricelist, supplanted by 4083-5 4093-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T .   Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4340
4093-5S 1936, 1937, 1939 Log Log Vector, listed as discontinued in the 1939 pricelist, supplanted by 4083-5S 4093-5 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany L LL0 DF = CF B CI C = D LL3 LL2 Sh1 Sh2 Th = SI1 SI2 TI = D S T . Sewed Leather Case Duplex   50cm (20 inch) IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4341
4094 1929, 1930 Merchants' (Mannheim) 4094 (1929) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CI C = D . .   Closed Frame   25cm (10 inch) E   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4342
4094 1934 Merchants' (Mannheim) (suspected to exist) 4094 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany DF = CF CI C = D . .   Closed Frame   25cm (10 inch) E   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4545
4094 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Merchants' (Mannheim), (Listed as temporarily discontinued in 1944 pricelist) 4094 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . .   Closed Frame   25cm (10 inch) EL 4L 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4343
N4094 1954, 1955 Merchants' Slide Rule 4094 (1954) Unbreakable Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . .   Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4344
68-1775 1962, 1967 Merchants' Slide Rule (O'Leary Collection) 4094 (1962) Unbreakable Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . New K&E conversion table Synthetic Leather Case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4345
4095 1900 Triangular Metal (Schure Collection) 4095 (1900) Three-sided metal frame with glass indicator windows Polished metal A = B C = D A = BI CI = D Third side A = S L T = D . Triangular metal   25cm (10 inch) . . . . . . . 4346
4095-1S 1922, 1925 Merchants' Adjustable Duplex 4095-1 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D . Sewed Leather Sheath Duplex   12.5cm (5 inch) K, 99-6807 8, 8W, 99-6820       U   4347
4095-1S 1927, 1928, 1930, 1934, 1936, 1937, 1939 Merchants' Adjustable Duplex 4095-1 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D . Sewed Leather Case without flap Duplex   12.5cm (5 inch) K, 99-6807 8, 8W, 99-6820       U   4348
9050-1 1950? Merchants' Pocket - "Doric" 4095-1 (1950) Unbreakable Indicator Engine Divided White Xylonite DF = CF CI C = D L . .   Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4351
4150-1 1952, 1954, 1955 Pocket Slide Rule (old 9050-1) 4095-1 (1952) Unbreakable Indicator Ivorite Precision Molded ABS DF = CF CI C = D L . . Leather Sheath Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4349
4150-1C 1960 Merchants' Pocket 4095-1 (1960) Unbreakable Indicator Ivorite Precision Molded ABS DF =CF CI C = D L . . leather sheath, with leather covered pocket clip Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230 AA, AF, 68-2349, 68-2352   4350
68-1786 1962, 1964, 1966, 1967, 1972 Merchants' Pocket 4095-1 (1962) Unbreakable Indicator Ivorite Precision Molded ABS DF = CF CI C = D L . . leather sheath, with leather covered pocket clip Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230 AA, AF, 68-2349, 68-2352   4352
68-1791 1962, 1964, 1966, 1967 Merchants' Pocket 4095-1 (1962) Unbreakable Indicator Ivorite Precision Molded ABS DF = CF CI C = D L . . Leather Sheath Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4353
4095 1914 Merchants' Adjustable Duplex 4095-3 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D .   Duplex   25cm (10 inch) H, 99-6808 5, 5W, 99-6818 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4530
4095 1915, 1921 Merchants' Adjustable Duplex 4095-3 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D .   Duplex   25cm (10 inch) H, 99-6808 5, 5W, 99-6818 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4354
4095-3 1922 Merchants' Adjustable Duplex, has indicator H and glass No. 5 (O'Leary Collection) 4095-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D . Hard case with snap flap Duplex   25cm (10 inch) H, 99-6808 5, 5W, 99-6818 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4355
4095-3S 1922 Merchants' Adjustable Duplex, has indicator H and glass No. 5 4095-3 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D .. Sewed Leather Sheath Duplex   25cm (10 inch) H, 99-6808 5, 5W, 99-6818 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4356
N4095-3 1925, 1927, 1928, 1930 Merchants' Adjustable Duplex, has indicator H and glass No. 5 (O'Leary Collection) 4095-3 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D Shown as 4095-3 in catalog, but has N4095-3 on slide rule, consistent with other models Hard case with snap flap Duplex   25cm (10 inch) H, 99-6808 5, 5W, 99-6818 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4697
N4095-3S 1925, 1927, 1928, 1930 Merchants' Adjustable Duplex, has indicator H and glass No. 5 4095-3 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D Shown as 4095-3 in catalog, but has N4095-3 on slide rule, consistent with other models Sewed Leather Case Duplex   25cm (10 inch) H, 99-6808 5, 5W, 99-6818 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4357
N4095-3 1934 Merchants' Adjustable Duplex (catalog shows 4095-3, and indicator chart shows N4095-3) 4095-3 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany DF = CF C = D =CI = D Shown as 4095-3 in catalog, but has N4095-3 on slide rule, consistent with other models   Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4509
N4095-3S 1934 Merchants' Adjustable Duplex (catalog shows 4095-3, and indicator chart shows N4095-3) 4095-3 (1934) Frameless Glass Indicator with plastic indicator bars, and protective flaps on corners Engine divided celluloid laminated mahogany DF = CF C = D =CI = D Shown as 4095-3 in catalog, but has N4095-3 on slide rule, consistent with other models Sewed Leather Case Duplex   25cm (10 inch) G   4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4514
4095-3 1936, 1937, 1939, 1942 Merchants' Adjustable Duplex 4095-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF C = D =CI = D .   Duplex   25cm (10 inch) GL, 99-6809 6L, 99-6819 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4358
4095-3S 1936, 1937, 1939, 1942 Merchants' Adjustable Duplex 4095-3 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF C = D =CI = D . Sewed Leather Case Duplex   25cm (10 inch) GL, 99-6809 6L, 99-6819 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4359
N4095-3 1944? Merchants' Adjustable Duplex, (Cerny Collection) 4095-3 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF C = D =CI = D .   Duplex   25cm (10 inch) GL, 99-6809 6L, 99-6819 4085-B, 4185-B, 4185-1, 68-2230   WP, 68-2273 W, 68-2337 WM, 68-2338 4521
4095-5 1922, 1925 Merchants' Adjustable Duplex 4095-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4360
4095-5S 1922, 1925 Merchants' Adjustable Duplex 4095-5 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D =CI = D . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4361
4096 1906, 1909, 1913, 1915 Mannheim, All Metal 4096 (1906) Glass Indicator with Metal Frame All metal DF = CF C = D . .   Closed Frame   25cm (10 inch) E             4362
4096 1927, 1928 Desk Slide Rule, on Metal Stands, Nickel Silver Knob, and Solid Rubber Buffers, no CI scale present 4096 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF C = D . K&E conversion table Leatheret Covered Case Closed Frame   50cm (20 inch) J   4085-B, 4185-B, 4185-1, 68-2230       4363
N4096 1930, 1934 Desk Slide Rule, on Metal Stands, Nickel Silver Knob, and Solid Rubber Buffers, with added CI scale 4096 (1930) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany DF = CF CI C = D . K&E conversion table Leatheret Covered Case Closed Frame   50cm (20 inch) J   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233         4364
N4096 1936, 1937, 1939, 1942 Desk Slide Rule, on Metal Stands, Nickel Silver Knob, and Solid Rubber Buffers 4096 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . K&E conversion table Leatheret Covered Case Closed Frame   50cm (20 inch) JL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233         4365
4096M 1939, 1942, 1943, 1944, 1947 Desk Slide Rule, (same as N4096, but without stand, knob, or special case) (Listed as temporarily discontinued in 1944 pricelist) 4096 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . K&E conversion table. This slide rule is marked <N4096> on the right end of slide. (From Jim Stewart's N4096) plain Morocco-covered case Closed Frame   50cm (20 inch) JL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233       4366
N4096 1949, 1952, 1954, 1955 Desk Slide Rule, on Metal Stands, Knob on slide 4096 (1949) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . K&E conversion table Special Case, no details given Closed Frame   50cm (20 inch) JL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233         4368
68-1749 1962, 1966, 1967 Desk Slide Rule, on Metal Stands, Knob on slide 4096 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . K&E conversion table leatherette-covered Wood Case Closed Frame   50cm (20 inch) JW, 68-2142 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233         4369
68-1754 1962, 1967 Desk Slide Rule, (same as 68-1749, but without stand, knob, or special case) 4096 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany DF = CF CI C = D . K&E conversion table synthetic case Closed Frame   50cm (20 inch) JW, 68-2142 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233       4370
4097 1934 Ever - There, White Xylonite, engine divided 4097 (1934) Frameless Glass Indicator with plastic indicator bars Engine Divided White Xylonite DF = CF CI C = D . 5inch 13cm high-grade Leather Sheath Closed Frame   12.5cm (5 inch) N2         AA, AF, 68-2349, 68-2352 4371
4097B 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Ever - There, White Xylonite, (Old 4097), engine divided 4097 (1936) Improved Glass Indicator Engine Divided White Xylonite DF = CF CI C = D . 5inch 13cm high-grade Leather Sheath Closed Frame   12.5cm (5 inch) N2         AA, AF, 68-2349, 68-2352 4372
4097C 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Ever - There, White Xylonite, (Old 4098), engine divided (Manuel Pacheco Collection) 4097 (1936) Improved Glass Indicator Engine Divided White Xylonite A = B CI C = D K = B S L T = 5inch 13cm high-grade Leather Sheath Closed Frame   12.5cm (5 inch) N2         AA, AF, 68-2349, 68-2352 4373
4097D 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Ever - There, White Xylonite, engine divided 4097 (1936) Improved Glass Indicator Engine Divided White Xylonite A DF = CF CI C = D K = B S L T = 5inch 13cm high-grade Leather Sheath Closed Frame   12.5cm (5 inch) N2         AA, AF, 68-2349, 68-2352 4374
4098 1906, 1909 Duplex, all metal, for Arithmetical Computations 4098 (1906) Glass Indicator with Metal Frame All metal . . .   Closed Frame   25cm (10 inch)               4375
4098 1913, 1915 Duplex, German Silver, for Arithmetical Computations 4098 (1909) Glass Indicator with Metal Frame Engine divided German silver . . .   Closed Frame   25cm (10 inch)               4376
4098 1934 Ever - There, White Xylonite, engine divided 4098 (1934) Improved Glass Indicator Engine Divided White Xylonite A = B CI C = D K = S L T = 5inch 13cm high-grade Leather Sheath Closed Frame   12.5cm (5 inch) N2         AA, AF, 68-2349, 68-2352 4377
4098A 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Pocket Slide Rule, White Xylonite 4098 (1936) Frameless transparent Xylonite Indicator Engine Divided White Xylonite A = B C = D = S L T = 5inch 13cm Leather Sheath Closed Frame   12.5cm (5 inch) N3         BB   4378
1749-3 1897, 1899 Colby's Slide Rule, for Stadia Reductions 4100 (1897) None hardwood, with a base and a slide, built in the fashion of a desktop nameplate . . . hardcase (?) Base and slide   50 inch               4380
4100 1900, 1901 Stadia 4100 (1900) None Engine divided celluloid laminated wood . . . hardcase (?) Closed Frame   25cm (10 inch)               4684
4125 1900? Colby's Stadia 4100 (1900) None Engine divided celluloid laminated mahogany . . .   Base and slide   50 inch               4381
4100 1903, 1906, 1909 Stadia, designed by Wm. Cox 4100 (1903) None Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = Has June 5,1900 patent adjustment   Closed Frame   25cm (10 inch)       RP, 68-2276 R, 68-2340 RM, 68-2341 4382
4100 1913 Stadia 4100 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = . Morocco Case Closed Frame   25cm (10 inch)     4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4383
4100 1914 Stadia (Rueb Collection) 4100 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = .   Closed Frame   25cm (10 inch) D   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4531
4100 1915, 1921, 1922 Stadia (O'Leary Collection) 4100 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = .   Closed Frame   25cm (10 inch) D   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4384
4100S 1922 Stadia 4100 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" the corrected rod reading = 100 X rod reading + (f + c), ' Sewed Leather Case Closed Frame   25cm (10 inch) D   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4385
N4100 1925, 1927, 1928, 1930, 1934 Stadia 4100 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" the corrected rod reading = 100 X rod reading + (f + c), '   Closed Frame   25cm (10 inch) D   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4386
N4100S 1925, 1927, 1928, 1930, 1934 Stadia 4100 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" the corrected rod reading = 100 X rod reading + (f + c), ' Sewed Leather Case Closed Frame   25cm (10 inch) D   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4387
N4100 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Stadia (O'Leary Collection) 4100 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" = 100 X rod reading + (f + c), on scale R. Over the vertical'   Closed Frame   25cm (10 inch) EL 4L 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4388
N4100S 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Stadia (O'Leary Collection) 4100 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" = 100 X rod reading + (f + c), on scale R. Over the vertical' Sewed Leather Case Closed Frame   25cm (10 inch) EL 4L 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4389
4100 1954, 1955 Stadia (O'Leary Collection) 4100 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany 12 inch(by 16ths) / R = H HC V = A ] 25cm = C B = In gutter, Second line, 'index, to "R," = 100 X rod reading + (f + c), on scale R.' On back, Conversion Factors   Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4390
4100S 1954, 1955 Stadia (O'Leary Collection) 4100 (1954) Improved Glass Indicator Engine divided celluloid laminated mahogany 12 inch(by 16ths) / R = H HC V = A ] 25cm = C B = In gutter, Second line, 'index, to "R," = 100 X rod reading + (f + c), on scale R.' On back, Conversion Factors Synthetic Leather Case. Catalog says sewed leather case Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4391
4143 1960 Kissam Stadia 4100 (1960) Improved Glass Indicator Ivorite Precision Molded ABS R1 = V1 HC V2 = R2 . K&E conversion table The top scale on the slide is actually three scales, marked V1 on the left, H in the middle in red, and V3 on the right.   Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4440
68-1486 1962, 1967 Kissam Stadia, (O'Leary Collection - note: 1968 version, assembled in Hoboken) 4100 (1962) Improved Glass Indicator Ivorite Precision Molded ABS R1 = V1 HC V2 = R2 . K&E conversion table The top scale on the slide is actually three scales, marked V1 on the left, H in the middle in red, and V3 on the right. Chamois lined Sewed Leather Case, with belt carrier Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4441
68-1486 1972 Kissam Stadia 4100 (1972) Improved Glass Indicator Ivorite Precision Molded ABS R1 = V1 HC V2 = R2 . K&E conversion table The top scale on the slide is actually three scales, marked V1 on the left, H in the middle in red, and V3 on the right. Sewed Leather Case, with belt carrier Closed Frame   25cm (10 inch) VW, 68-2130 10W, 68-2188 4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4442
1749 1895 Stadia 4101 (1895) None Engine divided celluloid laminated wood . . . . Closed Frame   50cm (20 inch)               4379
1749 1897, 1899 Stadia 4101 (1897) None Engine divided celluloid laminated wood . . . hardcase (?) Closed Frame   50cm (20 inch)               4493
4101 1900, 1901 Stadia 4101 (1900) None Engine divided celluloid laminated wood . . . hardcase (?) Closed Frame   50cm (20 inch)               4683
4101 1903, 1906, 1909 Stadia, designed by Wm. Cox 4101 (1903) None Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = Has June 5,1900 patent adjustment hardcase (?) Closed Frame   50cm (20 inch)       TP, 68-2282 T, 68-2355 TM, 68-2356 4392
4101 1913 Stadia 4101 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = . Morocco Case Closed Frame   50cm (20 inch)     4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4393
4101 1914 Stadia (suspected to exist) 4101 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = .   Closed Frame   50cm (20 inch) E   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4532
4101 1915, 1921, 1922 Stadia 4101 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = .   Closed Frame   50cm (20 inch) E   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4394
4101 1925 Stadia 4101 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" the corrected rod reading = 100 X rod reading + (f + c), '   Closed Frame   50cm (20 inch) E   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4395
4101S 1922, 1925 Stadia 4101 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Distance in feet = degrees: 30' to 45 degrees, to zero degrees degrees: 4' to ~5degrees 45' = B scale = A scale = On back, Second line, ' "Rc" the corrected rod reading = 100 X rod reading + (f + c), ' Sewed Leather Case Closed Frame   50cm (20 inch) E   4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4396
N4101 1927, 1928, 1930, 1934 Stadia 4101 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" the corrected rod reading = 100 X rod reading + (f + c), '   Closed Frame   50cm (20 inch) E   4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4397
N4101S 1927, 1928, 1930, 1934 Stadia 4101 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" the corrected rod reading = 100 X rod reading + (f + c), ' Sewed Leather Case Closed Frame   50cm (20 inch) E   4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4398
N4101 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Stadia 4101 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" = 100 X rod reading + (f + c), on scale R. Over the vertical' (not confirmed for all years)   Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4399
N4101S 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Stadia 4101 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany R = H HC V = A = C B = On back, Second line, ' "Rc" = 100 X rod reading + (f + c), on scale R. Over the vertical' (not confirmed for all years) Sewed Leather Case Closed Frame   50cm (20 inch) EL, 68-2139 4L, 68-2191 4085-B, 4185-B, 4185-1, 68-2230   TP, 68-2282 T, 68-2355 TM, 68-2356 4400
4102 1914 Surveyor's Duplex (suspected to exist) 4102 (1914) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany D Sin d = Cos l&h C Tan = Tan I Az Vert. 1/2 Sin 2a A = B Ci C = D Vert. 1/2 Sin 2a .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4533
4102 1915, 1921, 1922, 1925 Surveyor's Duplex 4102 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany D Sin d = Cos l&h C Tan = Tan I Az Vert. 1/2 Sin 2a A = B Ci C = D Vert. 1/2 Sin 2a .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4401
4102S 1922, 1925, 1927 Surveyor's Duplex 4102 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany D Sin d = Cos l&h C Tan = Tan I Az Vert. 1/2 Sin 2a A = B Ci C = D Vert. 1/2 Sin 2a . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4402
N4102 1927, 1928, 1930, 1934 Surveyor's Duplex 4102 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany D Sin d = Cos l&h C Tan = Tan I Az Vert. 1/2 Sin 2a A = B Ci C = D Vert. 1/2 Sin 2a .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4403
N4102S 1928, 1930, 1934 Surveyor's Duplex 4102 (1928) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany D Sin d = Cos l&h C Tan = Tan I Az Vert. 1/2 Sin 2a A = B Ci C = D Vert. 1/2 Sin 2a . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4185-8, 68-2221, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4404
N4102 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Surveyor's Duplex 4102 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany D Sin d = Cos l&h C Tan = Tan I Az Vert. 1/2 Sin 2a A = B Ci C = D Vert. 1/2 Sin 2a .   Duplex   50cm (20 inch) IL, IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233 4185-17, 68-2233 ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4405
N4102S 1936, 1937, 1939, 1942, 1943, 1944, 1947, 1949, 1952 Surveyor's Duplex 4102 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany D Sin d = Cos l&h C Tan = Tan I Az Vert. 1/2 Sin 2a A = B Ci C = D Vert. 1/2 Sin 2a . Sewed Leather Case Duplex   50cm (20 inch) IL, IaL 7L, 7W, 68-2176 4185-8, 68-2221, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4406
4105 1906, 1909, 1913, 1915, 1921, 1922, 1925 Webb's Stadia Slide Rule (Cylindrical), listed as discontinued in the 1925 pricelist 4105 (1909) None . . . .   Cylinder in sleeve   15 inch, 1.5 inch diameter               4407
4110 1942? - JOS, Mar. 1993 Special Rule made for Annapolis? Mannheim frame Log Log Rule with 33 1/3 inch scales. Info from Bob Otnes 4110 (1942) Improved Glass Indicator Engine divided celluloid laminated mahogany, [from Clark McCoy - built on the N4096 desktop rule frame, using the N4096 improved indicator] P F A = B T S CI C = D (C and D scales are double logarithmic scales, and A and B are fourfold logarithmic scales) [info from Clark McCoy's 4110 rule] . .   Closed Frame   14.5 inches with 13.25 inch scales               4408
1749-2 1897, 1899 Colby's Sewer Computer 4128 (1897) None hardwood, with a base and a slide, built in the fashion of a desktop nameplate . . . hardcase (?) Base and slide   50cm (20 inch)               4409
1749-4 1899 Crane's Sewer Slide Rule 4128 (1899) None Engine divided celluloid laminated mahogany 10-1000 logarithmic scale on left half of upper stator = Parts Full Diameter = 10-3000 logarithmic scale on left half of lower stator: Cu. Ft. per Second . .   Duplex                   4410
4130 1900, 1901, 1903, 1906 Colby's Sewer Computer 4128 (1900) None hardwood, with a base and a slide, built in the fashion of a desktop nameplate . . .   Base and slide   50cm (20 inch)               4411
4132 1900, 1901, 1903, 1906, 1909 Crane's Sewer Slide Rule, Paper Facing, no Indicator 4128 (1900) None appears to be wood, with paper facings . . .   Duplex   25cm (10 inch)               4412
4128 1913 Nordell Sewer Slide Rule, Duplex type 4128 (1913) Glass Indicator with Metal Frame . . . . Morocco Case Duplex   50cm (20 inch)     4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4413
4132 1913, 1915, 1921, 1925, 1927, 1928, 1929, 1930, 1934 Crane's Sewer Slide Rule, printed graduations, no Indicator. Listed as discontinued in 1929, 1930 & 1934 pricelists 4128 (1913) None . . . .   Duplex   25cm (10 inch)               4414
4128 1915, 1921, 1922, 1925 Nordell Sewer Slide Rule, Duplex type, listed as discontinued in the 1925 pricelist 4128 (1915) Frameless Glass Indicator with plastic indicator bars . . . .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4415
4128S 1922, 1925 Nordell Sewer Slide Rule, Duplex type, listed as discontinued in the 1925 pricelist 4128 (1922) Frameless Glass Indicator with plastic indicator bars . . . . Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4416
4133 1913 Roylance Electrical 4133 (1913) Glass Indicator with Metal Frame Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) C = D ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, K&E conversion table   Closed Frame   20cm (8 inch)         P PM 4417
4133 1914 Roylance Electrical 4133 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) C = D ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, K&E conversion table   Closed Frame   20cm (8 inch) C, 99-6803 2a, 2aW, 99-6816     P PM 4534
4133 1915, 1921 Roylance Electrical 4133 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) C = D ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, K&E conversion table   Closed Frame   20cm (8 inch) C, 99-6803 2a, 2aW, 99-6816     P PM 4418
4133S 1922 Roylance Electrical 4133 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) C = D ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, K&E conversion table Sewed Leather Case Closed Frame   20cm (8 inch) C, 99-6803 2a, 2aW, 99-6816     P PM 4419
N4133S 1923 Roylance Electrical (O'Leary Collection) 4133 (1923) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Marked N <4133> 8inch / A = B (Temp Degrees C) C = D ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, NBS Circular 47 conversion table. CI scale added Sewed Leather Case Closed Frame   20cm (8 inch) C, 99-6803 2a, 2aW, 99-6816     P PM 4713
N4133S 1924 Roylance Electrical (O'Leary Collection) 4133 (1924) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Marked N<4133> 8inch / A = B (Temp Degrees C) C = D ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, NBS Circular 47 conversion table. CI scale added Sewed Leather Case Closed Frame   20cm (8 inch) C, 99-6803 2a, 2aW, 99-6816     P PM 4650
N4133S 1925, 1927, 1928, 1930 Roylance Electrical (O'Leary Collection) 4133 (1925) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Marked <N4133> 8inch / A = B (Temp Degrees C) CI C = D ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, NBS Circular 47 conversion table. CI scale added Sewed Leather Case Closed Frame   20cm (8 inch) Ea 4a 4085-B, 4185-B, 4185-1, 68-2230     P PM 4517
N4133S 1934 Roylance Electrical 4133 (1934) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) CI C = D K ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, NBS Circular 47 conversion table. K scale added. Sewed Leather Case Closed Frame   20cm (8 inch) Ea 4a 4085-B, 4185-B, 4185-1, 68-2230     P PM 4420
N4133S 1936, 1937, 1939, 1942 Roylance Electrical 4133 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) CI C = D K ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, NBS Circular 47 conversion table Sewed Leather Case Closed Frame   20cm (8 inch) EaL, 99-6805 4aL, 99-6817 4085-B, 4185-B, 4185-1, 68-2230     P PM 4421
N4133 1944, 1947, 1949, 1952 Roylance Electrical (O'Leary Collection) 4133 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) CI C = D K ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, NBS Circular 47 conversion table   Closed Frame   20cm (8 inch) EaL, 99-6805 4aL, 99-6817 4085-B, 4185-B, 4185-1, 68-2230     P PM 4423
N4133S 1944, 1947, 1949, 1952 Roylance Electrical (Listed as temporarily discontinued in 1947 Pricelist) 4133 (1944) Improved Glass Indicator Engine divided celluloid laminated mahogany 8inch / A = B (Temp Degrees C) CI C = D K ] Brown & Sharpe Wire Gauge 0000 - 30 = S L T = # Current Capacity of Wire # On Back, NBS Circular 47 conversion table Unspecified Case Closed Frame   20cm (8 inch) EaL, 99-6805 4aL, 99-6817 4085-B, 4185-B, 4185-1, 68-2230     P PM 4422
4135 1915, 1921 Power Computing Rule 4135 (1915) None Engine divided celluloid laminated mahogany . . .   Two slide Duplex   7.25 inch               4424
N4135S 1922, 1925 Power Computing 4135 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B CI C = D P = R W = D . Sewed Leather Case Duplex   12.5cm (5 inch) K, 99-6807 8, 8W, 99-6820       U   4425
N4135S 1927, 1928, 1930, 1934, 1936, 1937, 1939 Power Computing, listed as discontinued in the 1939 pricelist 4135 (1927) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany A = B CI C = D P = R W = D . Sewed Leather Case without flap Duplex   12.5cm (5 inch) K, 99-6807 8, 8W, 99-6820       U   4426
4138 1939 Morrison Radio Engineer's Slide Rule 4138 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany (F left) L F A = B CI C = D T ST S (F Rt) db FREQ LC = = (Back left) 9 8 = 7 6 5 4 = 3 2 1 (Back right) Att. Factor II Att. Factor I = d,Miles Cd P,Watts f,Mc = (sigma),emu E,microwatt/m db .   Duplex   25cm (10 inch) IL, IaL 7L, 7W, 68-2176           4427
4138S 1939 Morrison Radio Engineer's Slide Rule 4138 (1939) Improved Glass Indicator Engine divided celluloid laminated mahogany (F left) L F A = B CI C = D T ST S (F Rt) db FREQ LC = = (Back left) 9 8 = 7 6 5 4 = 3 2 1 (Back right) Att. Factor II Att. Factor I = d,Miles Cd P,Watts f,Mc = (sigma),emu E,microwatt/m db . Sewed Leather Case Duplex   25cm (10 inch) IL, IaL 7L, 7W, 68-2176           4428
4139 1943, 1944, 1947, 1949, 1952, 1954, 1955 Cooke Radio Slide Rule 4139 (1943) Improved Glass Indicator Engine divided celluloid laminated mahogany L DF =CF CIF CI C = D 2pi LC A = B T ST S = D DI .   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4429
4139S 1943, 1944, 1947, 1949, 1952, 1954, 1955 Cooke Radio Slide Rule 4139 (1943) Improved Glass Indicator Engine divided celluloid laminated mahogany L DF =CF CIF CI C = D 2pi LC A = B T ST S = D DI . Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4430
4139 1955 (Sept.) Cooke Radio Slide Rule 4139 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany L DF =CF CIF CI C = D 2pi LC A = B T SRT S = D DI "SRT" scale added   Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4603
4139S 1955 (Sept.) Cooke Radio Slide Rule 4139 (1955) Improved Glass Indicator Engine divided celluloid laminated mahogany L DF =CF CIF CI C = D 2pi LC A = B T SRT S = D DI "SRT" scale added Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4604
68-1460 1962, 1967 Cooke Radio 4139 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany L DF =CF CIF CI C = D 2pi LC A = B T SRT S = D DI . Chamois lined Sewed Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4431
68-1465 1962, 1967 Cooke Radio 4139 (1962) Improved Glass Indicator Engine divided celluloid laminated mahogany L DF =CF CIF CI C = D 2pi LC A = B T SRT S = D DI . Synthetic Leather Case Duplex   25cm (10 inch) PL, 68-2127 9L, 68-2185 4185-9, 68-2227, 4185-19, 68-2236 4185-19, 68-2236 WP, 68-2273 W, 68-2337 WM, 68-2338 4432
4140 1900, 1901, 1903, 1906 Hudson's Horsepower Computing Scale 4140 (1900) None cardboard Indicated Horsepower = Revolutions and Piston Speed = Stroke Mean Pressure = Cylinder Diameter . . Sewed Leather Case Two slide closed frame   4.5 inch               4433
4141 1900, 1901, 1903, 1906 Hudson's Horsepower Computing Scale 4140 (1900) None boxwood Indicated Horsepower = Revolutions and Piston Speed = Stroke Mean Pressure = Cylinder Diameter . . Sewed Leather Case Two slide closed frame   4.5 inch               4434
4140 1909, 1913, 1915 Hudson's Horsepower Computing Scale 4140 (1909) None cardboard Indicated Horsepower = Revolutions and Piston Speed = Stroke Mean Pressure = Cylinder Diameter . . leather covered sheath Two slide closed frame   4.5 inch               4681
4140 1909, 1913, 1915 Hudson's Horsepower Computing Scale 4140 (1909) None cardboard Indicated Horsepower = Revolutions and Piston Speed = Stroke Mean Pressure = Cylinder Diameter . . leather covered sheath Two slide closed frame   4.5 inch               4435
4141 1909, 1913 Hudson's Horsepower Computing Scale 4140 (1909) None Celluloid laminated boxwood Indicated Horsepower = Revolutions and Piston Speed = Stroke Mean Pressure = Cylinder Diameter . . leather covered sheath Two slide closed frame   4.5 inch               4436
4141 1915 Hudson's Horsepower Computing Scale 4140 (1915) None Xylonite Indicated Horsepower = Revolutions and Piston Speed = Stroke Mean Pressure = Cylinder Diameter . . leather covered sheath Two slide closed frame   4.5 inch               4437
4142 1914 Allan Friction Head Rule (suspected to exist) 4142 (1914) Frameless Glass Indicator with metal indicator bars Engine divided celluloid laminated mahogany Steam scales Water Scales .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4535
4142 1915, 1921, 1922, 1925 Allan Friction Head Rule 4142 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Steam scales Water Scales .   Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4438
4142S 1922, 1925 Allan Friction Head Rule 4142 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Steam scales Water Scales . Sewed Leather Case Duplex   50cm (20 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4439
4158 1961 K-12 Prep, (O'Leary Collection) 4158 (1961) Molded Plastic Indicator Vinylite laminations, Heat stamped K A = B S CI T C = D L blank blank opaque green plastic sheath, with transparent front Duplex   25cm (10 inch) M6, 68-2145   KK, 68-2285   4443
68-1892 1962 K-12 Prep 4158 (1962) Molded Plastic Indicator Vinylite laminations, Heat stamped K A = B S CI T C = D L blank blank opaque BLACK plastic sheath, with transparent front Duplex   25cm (10 inch) M6, 68-2145   KK, 68-2285   4444
68-1892 1966, 1972 K-12 Prep, (O'Leary Collection) 4158 (1962) Molded Plastic Indicator Vinylite laminations, Heat stamped K A = B S CI T C = D L blank blank opaque green plastic sheath, with transparent front Duplex   25cm (10 inch) M6, 68-2145   KK, 68-2285   4445
68-1892 Desktop 1963 K-12 Prep, with molded plastic desktop mount, (O'Leary Collection) 4158 (1963) Molded Plastic Indicator Vinylite laminations, Heat stamped K A = B S CI T C = D L blank blank Comes in cardboard box with stylized waterfront view of city Duplex   25cm (10 inch) M6, 68-2145   KK, 68-2285   4577
4160 1915, 1921, 1922, 1925, 1927, 1928, 1930, 1934 Chemist's Duplex 4160 (1915) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Sought = Given C = D Sought = Given CI = D .   Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   XP, 68-2270 X, 68-2322 XM, 68-2323 4446
4160S 1922, 1925, 1927, 1928, 1930, 1934 Chemist's Duplex 4160 (1922) Frameless Glass Indicator with plastic indicator bars Engine divided celluloid laminated mahogany Sought = Given C = D Sought = Given CI = D . Sewed Leather Case Duplex   25cm (10 inch) I, or complete replacement with IL/7L set   4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   XP, 68-2270 X, 68-2322 XM, 68-2323 4447
4160 1936, 1937, 1939 Chemist's Duplex 4160 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany Sought = Given C = D Sought = Given CI = D .   Duplex   25cm (10 inch) IL, IaL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   XP, 68-2270 X, 68-2322 XM, 68-2323 4448
4160S 1936, 1937, 1939 Chemist's Duplex 4160 (1936) Improved Glass Indicator Engine divided celluloid laminated mahogany Sought = Given C = D Sought = Given CI = D . Sewed Leather Case Duplex   25cm (10 inch) IL, IaL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233   XP, 68-2270 X, 68-2322 XM, 68-2323 4449
9061-1 1951 Doric 4161-1 (1951) Unbreakable Indicator Engine Divided White Xylonite K DF = CF L CI C = D A = T ST S C = .   Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame           4450
4161-1 1952, 1954, 1955 Pocket Slide Rule, with molded plastic back 4161-1 (1952) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = . Leather Sheath Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4451
4161-1C 1960 Polyphase Pocket 4161-1 (1960) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = .   Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4453
68-1581 1962, 1964, 1966 Modern Polyphase Pocket 4161-1 (1962) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = . Leather Sheath, with leather covered pocket clip Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4455
68-1586 1962, 1964, 1966 Modern Polyphase Pocket 4161-1 (1962) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = . Leather Sheath Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4456
68-1581 1967, 1972 Jet-Math Pocket 4161-1 (1967) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = . Leather Sheath, with leather covered pocket clip Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4458
68-1586 1967 Jet-Math Pocket 4161-1 (1967) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = . Leather Sheath Closed Frame   12.5cm (5 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230     AA, AF, 68-2349, 68-2352   4459
4161-3 1954, 1955 Polyphase, with molded plastic back 4161-3 (1954) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = K&E conversion table Unspecified Sheath Closed Frame   25cm (10 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230   HH, 68-2279     4452
68-1576 1962 Modern Polyphase, square cornered base 4161-3 (1962) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = K&E conversion table Synthetic Leather Sheath Closed Frame   25cm (10 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230   HH, 68-2279     4454
68-1576 1967 Jet-Math 4161-3 (1967) Unbreakable Indicator Ivorite Precision Molded ABS K DF = CF L CI C = D A = T ST S C = K&E conversion table synthetic leather sheath Closed Frame   25cm (10 inch) N4, 68-2136 no replacement; indicator bars are riveted to frame 4085-B, 4185-B, 4185-1, 68-2230   HH, 68-2279     4457
4165 1921 Urea Index Rule 4165 (1900) Frameless Glass Indicator with plastic indicator bars . 10inch / D = Wt. C Ur. = E ] 25cm . .   Closed Frame   25cm (10 inch) E   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4460
4165S 1922, 1925 Urea Index Rule 4165 (1922) Frameless Glass Indicator with plastic indicator bars . 10inch / D = Wt. C Ur. = E ] 25cm . . Sewed Leather Case Closed Frame   25cm (10 inch) E   4085-B, 4185-B, 4185-1, 68-2230   RP, 68-2276 R, 68-2340 RM, 68-2341 4461
4166 1915? Unknown Duplex Rule, but listed in indicator tables 4166 (1915) Frameless Glass Indicator with plastic indicator bars . . . .   Duplex   50cm (20 inch) Ia   4185-8, 68-2221, 4185-17, 68-2233   ZP, 68-2267 Z, 68-2319 ZM, 68-2320 4462
480 1881, 1883 Ivory Sector, 6 inch, opens to 12 inch, Hand Divided 4175 (1881) None ivory . . .   Sector   12 inch               4485
481 1881, 1883 Boxwood Sector, 6 inch, opens to 12 inch, Hand Divided 4175 (1881) None boxwood . . .   Sector   12 inch               4486
1749-7 1897, 1899 Boxwood Sector, with brass joint, hand divided 4175 (1897) None boxwood, with brass joint . . .   Sector   12 inch               4494
1749-8 1897, 1899 Ivory Sector, German Silver Joint, Hand Divided 4175 (1897) None ivory, with German Silver joint . . .   Sector   12 inch               4464
4175 1900, 1901, 1903, 1906, 1909, 1913, 1915 Boxwood Sector, with brass joint, hand divided 4175 (1909) None boxwood, with brass joint . . .   Sector   12 inch               4463
4176 1900, 1901, 1903, 1906, 1909, 1913, 1915 Ivory Sector, German Silver Joint, Hand Divided 4175 (1909) None ivory, with German Silver joint . . .   Sector   12 inch               4495
4175 1936, 1937 Kurtz Psychrometric (Schumacher Collection) 4175 (1936) Improved Glass Indicator . Scales numbered 1 through 11 . Instructions   Closed Frame   25cm (10 inch) JL, JW, 68-2142 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233         4516
4175 1939 Kurtz Psychrometric, listed as a new item in the 1939 pricelist (Variant?) 4175 (1939) Improved Glass Indicator . . . .   Closed Frame   25cm (10 inch) JL, JW, 68-2142 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233         4465
4180 1913, 1915 Fraction Adder, Xylonite disc on white-faced polished wood base, with Stylus for operating 4180 (1913) . . . . .   Octagon wood base   4 inch               4466
N9081-1 1949, 1952 Doric Plastic Slide Rule, decitrig scales, all black markings 4181-1 (1949) Improved Glass Indicator Engine Divided White Xylonite LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 . leather sheath Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179           4228
4181-1 1953, 1954, 1955 Pocket Slide Rule, decitrig scales, all black markings 4181-1 (1953) Unbreakable Indicator Ivorite Precision Molded ABS LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T ST S = D DI LL1 All black markings, with riveted braces. Mandrel ("A1.", "A2.") leather sheath Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179       DD, DJ, 68-2328, 68-2331   4229
4181-1 1955 (Sept.) Pocket Slide Rule 4181-1 (1955) Unbreakable Indicator Ivorite Precision Molded ABS LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Black and red markings, with Black K+E logo. Mandrel "C2." leather sheath Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179       DD, DJ, 68-2328, 68-2331   4554
4181-1C 1959 Decitrig Pocket (Preceeds the 68-1282) 4181-1 (1959) Unbreakable Indicator Ivorite Precision Molded ABS LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Black and red markings, with Black K+E logo. Mandrel "C2." Leather Sheath with Pocket clip Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179       DD, DJ, 68-2328, 68-2331   4230
E4181J 1960 Jet-Log Jr. 4181-1 (1960) Unbreakable Indicator Ivorite Precision Molded ABS LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Black and red markings, with Black K+E logo. Mandrel "C2." Leather Sheath with Pocket clip Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179       DD, DJ, 68-2328, 68-2331   4231
68-1261 1962, 1964, 1967, 1972 Jet-Log Jr. 4181-1 (1962) Unbreakable Indicator Ivorite Precision Molded ABS LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Black and red markings, with Red K+E logo. Mandrel "C2:::", "C2:::." leather sheath, with leather covered pocket clip Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179       DD, DJ, 68-2328, 68-2331   4232
68-1282 1962, 1967 Decitrig Pocket (Old 4181-1C) 4181-1 (1962) Unbreakable Indicator Ivorite Precision Molded ABS LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Black and red markings, with Red K+E logo. Mandrel "C2:::", "C2:::." leather sheath, with leather covered pocket clip Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179       DD, DJ, 68-2328, 68-2331   4233
68-1287 1962, 1964, 1966, 1967 Decitrig Pocket 4181-1 (1962) Unbreakable Indicator Ivorite Precision Molded ABS LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 Black and red markings, with Red K+E logo. Mandrel "C2:::", "C2:::." leather sheath Duplex   12.5cm (5 inch) XW, 68-2124 12W, 68-2179       DD, DJ, 68-2328, 68-2331   4234
4181-3 1954, 1955 Log Log Duplex Decitrig, (O'Leary Collection) 4181-3 (1954) Improved Glass Indicator Ivorite Precision Molded ABS, with riveted braces LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . sewed leather case, with belt carrier Duplex   25cm (10 inch) IL 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 XJ, 68-2325 XM, 68-2323 4245
E4181 1960 Jet-Log (O'Leary Collection) 4181-3 (1960) Improved Glass Indicator Ivorite Precision Molded ABS, with hex screwed braces LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . sewed leather case, with belt carrier Duplex   25cm (10 inch) RW, 68-2121 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 XJ, 68-2325 XM, 68-2323 4247
68-1251 1962, 1967, 1972 Jet-Log, (O'Leary Collection) 4181-3 (1962) Improved Glass Indicator Ivorite Precision Molded ABS, with hex screwed braces LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . sewed leather case, with belt carrier Duplex   25cm (10 inch) RW, 68-2121 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 XJ, 68-2325 XM, 68-2323 4251
68-1256 1962, 1967 Jet-Log, (O'Leary Collection) 4181-3 (1962) Improved Glass Indicator Ivorite Precision Molded ABS, with hex screwed braces LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 L K A = B T SRT S = D DI LL1 . Synthetic Leather Case Duplex   25cm (10 inch) RW, 68-2121 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 XJ, 68-2325 XM, 68-2323 4252
4185 1915, 1927, 1934 Brunton Slope Chart, heavy cardboard 4185 (1915) heavy cardboard heavy cardboard . . .   Card   11 .675x11 inches               4467
68-1100 1962, 1967 Deci-Lon 10 68-1100 (1962) Deci-Lon 10 Indicator Ivorite Precision Molded ABS Sq1 Sq2 DF = CF CIF L CI C = D Ln0 Ln1 Ln2 Ln3 Ln-3 Ln-2 Ln-1 Ln-0 A = B T SRT S C = D DI K . Chamois lined Sewed Leather Case, with belt carrier Duplex   25cm (10 inch) 68-2105 68-2171       68-2283   4468
68-1929 1962, 1967 Demonstration rule, for use with 68-1100, 68-1130 68-1100 (1962) . redwood Sq1 Sq2 DF = CF CIF L CI C = D Ln0 Ln1 Ln2 Ln3 Ln-3 Ln-2 Ln-1 Ln-0 A = B T SRT S C = D DI K .   Duplex   6 Feet               4470
68-1950 1962, 1967 Trunnions (2) for mounting of Deci-Lon and Decitrig Demonstration Rules 68-1100 (1962) N/A steel V^2 V^1/2 A = B U^1/2 U^-1 U C = D V V^-1 . .       .               4471
68-1955 1967 Deci-Lon Projection Slide Rule 68-1100 (1967) Frameless Glass Indicator with plastic indicator bars clear "eye-ease" green unbreakable plastic, with red and black numbers Upper (frontview) Sq1 Sq2 DF = CF CIF L CI C = D Ln0 Ln1 Ln2 Ln3 Lower (Backview) Ln-3 Ln-2 Ln-1 Ln-0 A = B T SRT S C = D DI K . . plush-lined leatherette covered case clear plastic for overhead projector   25cm (10 inch)               4472
68-1100 1972 Deci-Lon 10 68-1100 (1972) Deci-Lon 10 Indicator Ivorite Precision Molded ABS Sq1 Sq2 DF = CF CIF L CI C = D Ln0 Ln1 Ln2 Ln3 Ln-3 Ln-2 Ln-1 Ln-0 A = B T SRT S C = D DI K Missing finger grooves due to mold modification Sewed Leather Case with belt carrier Duplex   25cm (10 inch) 68-2105 68-2171       68-2283   4473
68-1130 1962, 1964, 1967, 1972 Deci-Lon 5 68-1130 (1962) Deci-Lon 5 Indicator Ivorite Precision Molded ABS Sq1 Sq2 DF = CF CIF L CI C = D Ln0 Ln1 Ln2 Ln3 Ln-3 Ln-2 Ln-1 Ln-0 A = B T SRT S C = D DI K . Sewed Leather Case with leather covered pocket clip Duplex   12.5cm (5 inch) 68-2104 68-2170       68-2333   4469
68-1400 1967 Analon 68-1400 (1967) Glued up indicator Ivorite Precision Molded ABS V^2 V^1/2 A = B U^1/2 U^-1 U C = D V V^-1 . Dimensional Analysis Chart Sewed Leather Case Duplex   25cm (10 inch) 68-2106             4474
68-1565 (patent 1964), 1966, 1967, 1972 GP-12 68-1565 (1964) Glued up indicator Ivorite Precision Molded ABS Sq1 Sq2 DF = CF T SRT S CI C = D A K Conversion Scales And Factors . Synthetic Leather Sheath Duplex   25cm (10 inch) 68-2111             4475
9068 1949, 1952 Doric Plastic Slide Rule, trig scales in degrees and minutes. Replaced by 4168 in 1952. 9068 (1949) Improved Glass Indicator Engine Divided White Xylonite DF = CF CI C = D L K A = B ST S = D T . Leather Sheath Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346   4477
4168 1952 Doric Plastic Slide Rule, trig scales in degrees and minutes. Replaced 9068. 9068 (1952) Improved Glass Indicator Engine Divided White Xylonite DF = CF CI C = D L K A = B ST S = D T . Leather Sheath Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346   4476
4168 1954, 1955 Pocket Slide Rule 9068 (1954) Unbreakable Indicator Ivorite Precision Molded ABS DF =CF CI C = D L K A = B ST S = D T . Leather Sheath Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346   4478
4168C 1960 Polyphase Duplex Pocket 9068 (1960) Unbreakable Indicator Ivorite Precision Molded ABS DF =CF CI C = D L K A = B ST S = D T .   Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346   4480
68-1550 1962, 1964, 1967, 1972 Polyphase Duplex Pocket 9068 (1962) Unbreakable Indicator Ivorite Precision Molded ABS DF =CF CI C = D L K A = B ST S = D T . Leather Sheath with leather covered pocket clip Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346   4481
68-1555 1962, 1964, 1967 Polyphase Duplex Pocket 9068 (1962) Unbreakable Indicator Ivorite Precision Molded ABS DF =CF CI C = D L K A = B ST S = D T . Leather Sheath Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346   4482
Celanese Celcon 1968 Pocket Slide Rule, special order, and very difficult to produce. 9068 (1968) Unbreakable Indicator Made using the Celanese light green resin DF =CF CI C = D L K A = B ST S = D T . Leather Sheath Duplex   12.5cm (5 inch) TW, 68-2133 10W, 68-2188       CC, CF, 68-2343, 68-2346   4479
N9081-3 1949, 1952 Doric Plastic Slide Rule, decitrig scales, all black markings. Replaced by N4181-3, 1952. 9081-3 (1949) Improved Glass Indicator Engine Divided White Xylonite LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 .   Duplex   25cm (10 inch) RW, 68-2121 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 X, 68-2322 XM, 68-2323 4241
N4181-3 1952, 1953 Log Log Duplex Decitrig. Replaced N9081-3 9081-3 (1950) Improved Glass Indicator Engine Divided White Xylonite LL02 LL03 DF = CF CIF CI C = D LL3 LL2 LL01 K A = B T ST S = D L LL1 .   Duplex   25cm (10 inch) RW, 68-2121 7L, 7W, 68-2176 4085-C, 4185-C, 4185-7, 68-2224, 4185-17, 68-2233 4185-17, 68-2233 XP, 68-2270 XJ, 68-2325 XM, 68-2323 4242
4183   Belt Carrier, orange Belt Carrier                        
4183B   Belt Carrier, black Belt Carrier                        
4183C   Belt Carrier, Dozen on a Card Belt Carrier                        
4183G   Belt Carrier Belt Carrier                        
68-2088   Belt Carrier Belt Carrier                        
68-2090   Belt Carrier Belt Carrier                        
68-2092   Belt Carrier Belt Carrier                        
68-2092   Belt Carrier, Dozen on a Card Belt Carrier                        
68-2267   Case, Plain Case   4080-5, 4080-5S, 4081-5, 4081-5S, 4083-5, 4083-5S, 4088-5, 4088-5S, 4092-5, 4092-5S, 4093-5, 4903-5S, 4095-5, 4095-5S, 4102, 4102S, 4128, 4128S, 4142, 4142S, 4166, 68-1200, 68-1205, 68-1308, 68-1313, 68-1424, 68-1429, N4080-5, N4081-5, N4083-5, N4088-5, N4088-5S, N4092-5, N4092-5S, N4102, N4102S             50cm (20 inch)         ZP, 68-2267 Z, 68-2319 ZM, 68-2320  
68-2270   Case, Plain Case   4080-3, 4080-3S, 4081-3, 4081-3S, 4083-3, 4083-3S, 4090-3, 4090-3S, 4091-3, 4091-3S, 4092-3, 4092-3S, 4093-3, 4093-3S, 4160, 4160S, 4181-3, 68-1210, 68-1215, 68-1220, 68-1251, 68-1256, 68-1318, 68-1323, 68-1434, 68-1439, E4081, E4181, N4080-3, N4081-3, N4083-3, N9081-3             25cm (10 inch)         XP, 68-2270 X, 68-2322 XM, 68-2323  
68-2273   Case, Plain Case   4070-3, 4070-3S, 4071-3, 4071-3S, 4088-3, 4088-3S, 4095, 4095-3, 4095-3S, 4139, 4139S, 68-1460, 68-1465, 68-1497, 68-1502, 68-1524, 68-1529             25cm (10 inch)         WP, 68-2273 W, 68-2337 WM, 68-2338  
68-2276   Case, Plain Case   4056, 4094, 4053-3, 4053-3 (old), 4053-F, 4053-3FS, 4053-3S, 4053-3S (old), 4100, 4100 (old), 4100S, 4143, 4165, 68-1486, 68-1607, 68-1612, 68-1617, 68-1622, 68-1775, N4053-3, N4053-3F, N4053-3FS, N4053-3S, N4041, N4041F, N4041FS, N4041S, N4094, N4100, N4100S             25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341  
68-2279   Case, Plain Case   4058W, 4161-3, 68-1576, N4058W             25cm (10 inch)         HH, 68-2279      
68-2282   Case, Plain Case   4051,4051S, 4053-5, 4053-5S, 4101, 4101S, 68-1607, 68-1612, N4053-5, N4053-5S, N4101, N4101S                       TP, 68-2282 T, 68-2355 TM, 68-2356  
68-2283   Case, DeciLon 10 Case                 25cm (10 inch)           68-2283    
68-2285   Case, K-12 Prep, Plastic Case   4158, 68-1892             25cm (10 inch)         KK, 68-2285      
68-2319   Case, Sewed Leather Case   4080-5, 4080-5S, 4081-5, 4081-5S, 4083-5, 4083-5S, 4088-5, 4088-5S, 4092-5, 4092-5S, 4093-5, 4903-5S, 4095-5, 4095-5S, 4102, 4102S, 4128, 4128S, 4142, 4142S, 4166, 68-1200, 68-1205, 68-1308, 68-1313, 68-1424, 68-1429, N4080-5, N4081-5, N4083-5, N4088-5, N4088-5S, N4092-5, N4092-5S, N4102, N4102S             50cm (20 inch)         ZP, 68-2267 Z, 68-2319 ZM, 68-2320  
68-2320   Case, fitted for Magnifier Case   4080-5, 4080-5S, 4081-5, 4081-5S, 4083-5, 4083-5S, 4088-5, 4088-5S, 4092-5, 4092-5S, 4093-5, 4903-5S, 4095-5, 4095-5S, 4102, 4102S, 4128, 4128S, 4142, 4142S, 4166, 68-1200, 68-1205, 68-1308, 68-1313, 68-1424, 68-1429, N4080-5, N4081-5, N4083-5, N4088-5, N4088-5S, N4092-5, N4092-5S, N4102, N4102S             50cm (20 inch)         ZP, 68-2267 Z, 68-2319 ZM, 68-2320  
68-2322   Case, Sewed Leather Case   4080-3, 4080-3S, 4081-3, 4081-3S, 4083-3, 4083-3S, 4090-3, 4090-3S, 4091-3, 4091-3S, 4092-3, 4092-3S, 4093-3, 4093-3S, 4160, 4160S, 4181-3, 68-1210, 68-1215, 68-1220, 68-1251, 68-1256, 68-1318, 68-1323, 68-1434, 68-1439, E4081, E4181, N4080-3, N4081-3, N4083-3, N9081-3             25cm (10 inch)         XP, 68-2270 X, 68-2322 XM, 68-2323  
68-2323   Case, fitted for Magnifier Case   4080-3, 4080-3S, 4081-3, 4081-3S, 4083-3, 4083-3S, 4090-3, 4090-3S, 4091-3, 4091-3S, 4092-3, 4092-3S, 4093-3, 4093-3S, 4160, 4160S, 4181-3, 68-1210, 68-1215, 68-1220, 68-1251, 68-1256, 68-1318, 68-1323, 68-1434, 68-1439, E4081, E4181, N4080-3, N4081-3, N4083-3, N9081-3             25cm (10 inch)         XP, 68-2270 X, 68-2322 XM, 68-2323  
68-2328   Case, Sewed Leather with Clip Case   4181-1, 4181-1C, 68-1261, 68-1282, 68-1287, E4181J             12.5cm (5 inch)           DD, DJ, 68-2328, 68-2331    
68-2331   Case, Sewed Leather Case   4181-1, 4181-1C, 68-1261, 68-1282, 68-1287, E4181J             12.5cm (5 inch)           DD, DJ, 68-2328, 68-2331    
68-2333   Case, Deci-Lon 5 Case                 12.5cm (5 inch) 68-2104 68-2170       68-2333    
68-2337   Case, Sewed Leather Case   4070-3, 4070-3S, 4071-3, 4071-3S, 4088-3, 4088-3S, 4095, 4095-3, 4095-3S, 4139, 4139S, 68-1460, 68-1465, 68-1497, 68-1502, 68-1524, 68-1529             25cm (10 inch)         WP, 68-2273 W, 68-2337 WM, 68-2338  
68-2338   Case, fitted for Magnifier Case   4070-3, 4070-3S, 4071-3, 4071-3S, 4088-3, 4088-3S, 4095, 4095-3, 4095-3S, 4139, 4139S, 68-1460, 68-1465, 68-1497, 68-1502, 68-1524, 68-1529             25cm (10 inch)         WP, 68-2273 W, 68-2337 WM, 68-2338  
68-2340   Case, Sewed Leather Case   4056, 4094, 4053-3, 4053-3 (old), 4053-F, 4053-3FS, 4053-3S, 4053-3S (old), 4100, 4100 (old), 4100S, 4143, 4165, 68-1486, 68-1607, 68-1612, 68-1617, 68-1622, 68-1775, N4053-3, N4053-3F, N4053-3FS, N4053-3S, N4041, N4041F, N4041FS, N4041S, N4094, N4100, N4100S             25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341  
68-2341   Case, fitted for Magnifier Case   4056, 4094, 4053-3, 4053-3 (old), 4053-F, 4053-3FS, 4053-3S, 4053-3S (old), 4100, 4100 (old), 4100S, 4143, 4165, 68-1486, 68-1607, 68-1612, 68-1617, 68-1622, 68-1775, N4053-3, N4053-3F, N4053-3FS, N4053-3S, N4041, N4041F, N4041FS, N4041S, N4094, N4100, N4100S             25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341  
68-2343   Case, Sewed Leather Case   4168, 4168C, 68-1550, 68-1555, 9068, 10000, 10002             12.5cm (5 inch) . .       CC, CF, 68-2343, 68-2346    
68-2346   Case, Sewed Leather with Clip Case   4168, 4168C, 68-1550, 68-1555, 9068, 10000, 10002             12.5cm (5 inch) . .       CC, CF, 68-2343, 68-2346    
68-2349   Case, Sewed Leather Case   4097, 4907B, 4097C, 4097D, 4098, 4150-1, 4150-1C, 4153-1C, 4161-1, 4161-1C, 68-1581, 68-1586, 68-1643, 68-1648, 68-1786, 68-1791             12.5cm (5 inch) .         AA, AF, 68-2349, 68-2352  
68-2352   Case, Sewed Leather with Clip Case   4097, 4907B, 4097C, 4097D, 4098, 4150-1, 4150-1C, 4153-1C, 4161-1, 4161-1C, 68-1581, 68-1586, 68-1643, 68-1648, 68-1786, 68-1791             12.5cm (5 inch) .         AA, AF, 68-2349, 68-2352  
68-2355   Case, Sewed Leather Case   4051,4051S, 4053-5, 4053-5S, 4101, 4101S, 68-1607, 68-1612, N4053-5, N4053-5S, N4101, N4101S             50cm (20 inch)         TP, 68-2282 T, 68-2355 TM, 68-2356  
68-2356   Case, fitted for Magnifier Case   4051,4051S, 4053-5, 4053-5S, 4101, 4101S, 68-1607, 68-1612, N4053-5, N4053-5S, N4101, N4101S                       TP, 68-2282 T, 68-2355 TM, 68-2356  
AA   Case, Sewed Leather Sheath Case   4097, 4907B, 4097C, 4097D, 4098, 4150-1, 4150-1C, 4153-1C, 4161-1, 4161-1C, 68-1581, 68-1586, 68-1643, 68-1648, 68-1786, 68-1791             12.5cm (5 inch) .         AA, AF, 68-2349, 68-2352  
AF   Case, Sewed Leather Sheath Case   4097, 4907B, 4097C, 4097D, 4098, 4150-1, 4150-1C, 4153-1C, 4161-1, 4161-1C, 68-1581, 68-1586, 68-1643, 68-1648, 68-1786, 68-1791             12.5cm (5 inch) .         AA, AF, 68-2349, 68-2352  
BB   Case, Sewed Leather Sheath Case   4098A             12.5cm (5 inch) .         BB    
CC   Case, Sewed Leather Case   4168, 4168C, 68-1550, 68-1555, 9068, 10000, 10002             12.5cm (5 inch) . .       CC, CF, 68-2343, 68-2346    
CF   Case, Sewed Leather with Clip Case   4168, 4168C, 68-1550, 68-1555, 9068, 10000, 10002             12.5cm (5 inch) . .       CC, CF, 68-2343, 68-2346    
DD   Case, Sewed Leather Case   4181-1, 4181-1C, 68-1261, 68-1282, 68-1287, E4181J             12.5cm (5 inch)           DD, DJ, 68-2328, 68-2331    
DJ   Case, Sewed Leather with Clip Case   4181-1, 4181-1C, 68-1261, 68-1282, 68-1287, E4181J             12.5cm (5 inch)           DD, DJ, 68-2328, 68-2331    
HH   Case, Plain Case   4058W, 4161-3, 68-1576, N4058W             25cm (10 inch)         HH, 68-2279      
KK   Case, K-12 Prep, Plastic Case   4158, 68-1892             25cm (10 inch)         KK, 68-2285      
O   Case, Sewed Leather Case   4031, 4031S             12.5cm (5 inch)     O    
OM   Case, fitted for Magnifier Case   4031, 4031S             12.5cm (5 inch)             OM  
P   Case, Sewed Leather Case   4035, 4035S, 4053-2, 4053-2S, 4143, N4035, N4035S, N4053-2, N4053-2S, N4133, N4133S             20cm (8 inch)       P    
PM   Case, fitted for Magnifier Case   4035, 4035S, 4053-2, 4053-2S, 4143, N4035, N4035S, N4053-2, N4053-2S, N4133, N4133S             20cm (8 inch)             PM  
R   Case, Sewed Leather Case   4056, 4094, 4053-3, 4053-3 (old), 4053-F, 4053-3FS, 4053-3S, 4053-3S (old), 4100, 4100 (old), 4100S, 4143, 4165, 68-1486, 68-1607, 68-1612, 68-1617, 68-1622, 68-1775, N4053-3, N4053-3F, N4053-3FS, N4053-3S, N4041, N4041F, N4041FS, N4041S, N4094, N4100, N4100S             25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341  
RM   Case, fitted for Magnifier Case   4056, 4094, 4053-3, 4053-3 (old), 4053-F, 4053-3FS, 4053-3S, 4053-3S (old), 4100, 4100 (old), 4100S, 4143, 4165, 68-1486, 68-1607, 68-1612, 68-1617, 68-1622, 68-1775, N4053-3, N4053-3F, N4053-3FS, N4053-3S, N4041, N4041F, N4041FS, N4041S, N4094, N4100, N4100S             25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341  
RP   Case, Plain Case   4056, 4094, 4053-3, 4053-3 (old), 4053-F, 4053-3FS, 4053-3S, 4053-3S (old), 4100, 4100 (old), 4100S, 4143, 4165, 68-1486, 68-1607, 68-1612, 68-1617, 68-1622, 68-1775, N4053-3, N4053-3F, N4053-3FS, N4053-3S, N4041, N4041F, N4041FS, N4041S, N4094, N4100, N4100S             25cm (10 inch)         RP, 68-2276 R, 68-2340 RM, 68-2341  
S   Case, Sewed Leather Case   4045, 4045S             42cm (16 inch)           S  
SM   Case, fitted for Magnifier Case   4045, 4045S             42cm (16 inch)           SM  
T   Case, Sewed Leather Case   4051,4051S, 4053-5, 4053-5S, 4101, 4101S, 68-1607, 68-1612, N4053-5, N4053-5S, N4101, N4101S             50cm (20 inch)         TP, 68-2282 T, 68-2355 TM, 68-2356  
TM   Case, fitted for Magnifier Case   4051,4051S, 4053-5, 4053-5S, 4101, 4101S, 68-1607, 68-1612, N4053-5, N4053-5S, N4101, N4101S             50cm (20 inch)         TP, 68-2282 T, 68-2355 TM, 68-2356  
TP   Case, Plain Case   4051,4051S, 4053-5, 4053-5S, 4101, 4101S, 68-1607, 68-1612, N4053-5, N4053-5S, N4101, N4101S             50cm (20 inch)         TP, 68-2282 T, 68-2355 TM, 68-2356  
U   Case, Sewed Leather Sheath Case   4088-1, 4088-1S, 4095-1, 4095-1S, N4135, N4135S             12.5cm (5 inch)           U    
V   Case, Sewed Leather Case   4088-2, 4088-2S             20cm (8 inch)           V    
VM   Case, fitted for Magnifier Case   4088-2, 4088-2S             20cm (8 inch)             VM  
W   Case, Sewed Leather Case   4070-3, 4070-3S, 4071-3, 4071-3S, 4088-3, 4088-3S, 4095, 4095-3, 4095-3S, 4139, 4139S, 68-1460, 68-1465, 68-1497, 68-1502, 68-1524, 68-1529             25cm (10 inch)         WP, 68-2273 W, 68-2337 WM, 68-2338  
WM   Case, fitted for Magnifier Case   4070-3, 4070-3S, 4071-3, 4071-3S, 4088-3, 4088-3S, 4095, 4095-3, 4095-3S, 4139, 4139S, 68-1460, 68-1465, 68-1497, 68-1502, 68-1524, 68-1529             25cm (10 inch)         WP, 68-2273 W, 68-2337 WM, 68-2338  
WP   Case, Plain Case   4070-3, 4070-3S, 4071-3, 4071-3S, 4088-3, 4088-3S, 4095, 4095-3, 4095-3S, 4139, 4139S, 68-1460, 68-1465, 68-1497, 68-1502, 68-1524, 68-1529             25cm (10 inch)         WP, 68-2273 W, 68-2337 WM, 68-2338  
X   Case, Sewed Leather Case   4080-3, 4080-3S, 4081-3, 4081-3S, 4083-3, 4083-3S, 4090-3, 4090-3S, 4091-3, 4091-3S, 4092-3, 4092-3S, 4093-3, 4093-3S, 4160, 4160S, 4181-3, 68-1210, 68-1215, 68-1220, 68-1251, 68-1256, 68-1318, 68-1323, 68-1434, 68-1439, E4081, E4181, N4080-3, N4081-3, N4083-3, N9081-3             25cm (10 inch)         XP, 68-2270 X, 68-2322 XM, 68-2323  
XM   Case, fitted for Magnifier Case   4080-3, 4080-3S, 4081-3, 4081-3S, 4083-3, 4083-3S, 4090-3, 4090-3S, 4091-3, 4091-3S, 4092-3, 4092-3S, 4093-3, 4093-3S, 4160, 4160S, 4181-3, 68-1210, 68-1215, 68-1220, 68-1251, 68-1256, 68-1318, 68-1323, 68-1434, 68-1439, E4081, E4181, N4080-3, N4081-3, N4083-3, N9081-3             25cm (10 inch)         XP, 68-2270 X, 68-2322 XM, 68-2323  
XP   Case, Plain Case   4080-3, 4080-3S, 4081-3, 4081-3S, 4083-3, 4083-3S, 4090-3, 4090-3S, 4091-3, 4091-3S, 4092-3, 4092-3S, 4093-3, 4093-3S, 4160, 4160S, 4181-3, 68-1210, 68-1215, 68-1220, 68-1251, 68-1256, 68-1318, 68-1323, 68-1434, 68-1439, E4081, E4181, N4080-3, N4081-3, N4083-3, N9081-3             25cm (10 inch)         XP, 68-2270 X, 68-2322 XM, 68-2323  
Z   Case, Sewed Leather Case   4080-5, 4080-5S, 4081-5, 4081-5S, 4083-5, 4083-5S, 4088-5, 4088-5S, 4092-5, 4092-5S, 4093-5, 4903-5S, 4095-5, 4095-5S, 4102, 4102S, 4128, 4128S, 4142, 4142S, 4166, 68-1200, 68-1205, 68-1308, 68-1313, 68-1424, 68-1429, N4080-5, N4081-5, N4083-5, N4088-5, N4088-5S, N4092-5, N4092-5S, N4102, N4102S             50cm (20 inch)         ZP, 68-2267 Z, 68-2319 ZM, 68-2320  
ZM   Case, fitted for Magnifier Case   4080-5, 4080-5S, 4081-5, 4081-5S, 4083-5, 4083-5S, 4088-5, 4088-5S, 4092-5, 4092-5S, 4093-5, 4903-5S, 4095-5, 4095-5S, 4102, 4102S, 4128, 4128S, 4142, 4142S, 4166, 68-1200, 68-1205, 68-1308, 68-1313, 68-1424, 68-1429, N4080-5, N4081-5, N4083-5, N4088-5, N4088-5S, N4092-5, N4092-5S, N4102, N4102S             50cm (20 inch)         ZP, 68-2267 Z, 68-2319 ZM, 68-2320  
ZP   Case, Plain Case   4080-5, 4080-5S, 4081-5, 4081-5S, 4083-5, 4083-5S, 4088-5, 4088-5S, 4092-5, 4092-5S, 4093-5, 4903-5S, 4095-5, 4095-5S, 4102, 4102S, 4128, 4128S, 4142, 4142S, 4166, 68-1200, 68-1205, 68-1308, 68-1313, 68-1424, 68-1429, N4080-5, N4081-5, N4083-5, N4088-5, N4088-5S, N4092-5, N4092-5S, N4102, N4102S             50cm (20 inch)         ZP, 68-2267 Z, 68-2319 ZM, 68-2320  
1   "Frameless" Glass Indicator   4031, 4031S             12.5cm (5 inch) A, 99-6801 1W, 99-6813        
2   "Frameless" Glass Indicator   4035, 4035S             20cm (8 inch) B 2W, 99-6814          
4086 1909, 1913, 1915, 1921, 1925, 1927, 1928, 1934 Glass Indicator with Decimal Pointer Indicator   4031, 4035, 4041, 4041F, 4054, 4056                              
4052DL 1906, 1909, 1913, 1915, 1921, 1922, 1925 Framed Glass Indicator with Two Hairlines, listed as discontinued in the 1925 pricelist Indicator   4031, 4035, 4041, 4041F, 4045, 4051                              
4052DL 1913, 1915, 1921, 1922, 1925 Framed Glass Indicator with Two Hairlines, to stated ratio, listed as discontinued in the 1925 pricelist Indicator   4031, 4035, 4041, 4041F, 4045, 4051                              
4052DL 1915, 1921, 1922 Frameless Glass Indicator with Two Hairlines, to stated ratio Indicator   4031, 4035, 4041, 4041F, 4045, 4051                              
4052DP 1906 Glass Indicator with Decimal Pointer Indicator   4031, 4035, 4041, 4041F, 4054, 4056                              
4081V 1906 Vernier to Index Line on Indicator, for reading the scale of equal parts (Logarithms) on the edge of rules with trig scales only, reads to four places Indicator   4069, 4069 1/2, 4075N, 4076N, 4084, 4085, 4088, 4089                              
4087V 1909 Vernier to Index Line on Indicator, for reading the scale of equal parts (Logarithms) on the edge of rules with trig scales only, reads to four places Indicator   4061T, 4065T, 4071T, 4083T, 4087T                              
68-2104   Indicator, Deci-Lon 5 Indicator   68-1130             12.5cm (5 inch) 68-2104 68-2170          
68-2105   Indicator, Deci-Lon 10 Indicator   68-1100             25cm (10 inch) 68-2105 68-2171          
68-2115   Indicator Indicator   4166, 4080-5, 4080-5S, 4081-5, 4081-5S, 4083-5, 4083-5S, 4093-5, 4093-5S, N4080-5, N4081-5, N4083-5, N4088-5, N4088-5S, N4092-5, N4092-5S, N4102, N4102S             50cm (20 inch) IaL, IaW, 68-2115 7L, 7W, 68-2176    
68-2118   Indicator Indicator   4102, 4128, 4142, 4160, 4080-3, 4080-3S, 4081-3, 4081-3S, 4083-3, 4083-3S, 4088-5, 4088-5S, 4090-3, 4090-3S, 4091-3, 4091-3S, 4092-3, 4092-3S, 4092-5, 4092-5S, 4093-3, 4093-3S, 4095-5, 4095-5S, 4102S, 4128S, 4142S, 4160S, E4081, N4080-3, N4081-3, N4083-3             50cm (20 inch) IL, IW, 68-2118 7L, 7W, 68-2176  
68-2121   Indicator Indicator   4181-3, E4181, N9081-3             25cm (10 inch) RW, 68-2121 7L, 7W, 68-2176  
68-2124   Indicator Indicator   4181-1, 4181-1C, E4181J             12.5cm (5 inch) XW, 68-2124 12W, 68-2179          
68-2127   Indicator Indicator   4139, 4070-3, 4070-3S, 4071-3, 4071-3S, 4139S             25cm (10 inch) PL 68-2127 9L, 68-2185  
68-2130   Indicator Indicator   4045, 4051, 4054, 4055, 4094, 4096(Metal), 4100, 4101, 4143, 4165, 4045S, 4051S, 4053-3, 4053-3S, N4035, N4035S, N4041, N4041F, N4041FS, N4041S, N4053-2, N4053-2S, N4053-3, N4053-3F, N4053-FS, N4053-3S, N4053-5, N4053-5S, N4094, N4100, N4100S, N4101, N4101S             EL, VW, 68-2130, 68-2139 4L, 10W, 68-2188, 68-2191