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Collection of pages from K&E catalogs for the 4012/4013 Thacher's family of slide rules
Description:
The 4012 and 4013 are cylindrical slide rules designed by Edwin Thacher in the late 1800s. It was patented in 1881. In 1891 K&E purchased the rights to the patent and began producing it.
The rule is a series of segmented B, C, & D scales arranged on a rotating cylinder. The 4012 is the basic rule. The 4013 is a 4012 with a magnifying glass mounted on it.
The rule was produced by K&E from 1891 to 1952. There were 3 variations in the construction methods over the life of the product:
Type I ---- Model numbers 1740 and 1741 produced from 1891 to 1899.
Type II --- Model numbers 4012 and 4013 produced from 1900 to 1927.
Type III -- Model numbers N4012 and N4013 produced from 1927 to 1942. The N4012 continued on till 1952.
The following models are part of the 4012 family:
- 1740N ---- Type I Thacher
- 1740 ------ Type I Thacher
- 1741 ------ Type I Thacher with a magnifier
- 4012 ------ Type II Thacher
- 4013 ------ Type II Thacher with a magnifier
- N4012 ---- Type III Thacher
- N4013 ---- Type III Thacher with a magnifier
History:
The origin of the Thacher's slide rule is known from other sources than K&E catalogs. The following is a list of catalog entries from 1887 to 1952.
- 1887 -- The 1740N was first shown.
- 1890 -- The N was dropped from the 1740.
- 1892 -- The 1741 was first shown.
- 1901 -- The Type II 4012 and 4013 models were introduced.
- 1927a - The Type III N4012 and N4013 models were introduced.
- 1943 -- The N4013 is not shown in this and later catalogs.
- 1952 -- The N4012 was last mentioned in the 1952 price list.
Links to catalog pages for the 4012 family of slide rules:
Link to scans of Thacher Calculators