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