Keuffel & Esser 4013 Thacher Cylindrical Slide Rule

This desktop slide rule is in a mahogany case. It has a cylindrical brass drum covered with paper printed with forty A scales. A wooden handle is fastened to each end of the drum. The drum fits in an open rotating brass frame; twenty brass slats span the frame. The right side of the paper on the drum is printed in italics: Patented by Edwin Thatcher [sic], C.E. Nov. 1st 1881. Made by Keuffel & Esser Co. N.Y.
The slats are lined with cloth and covered with paper. Each slat is printed with two B and two C scales. The first A scale runs from 100 to 112; the fortieth runs from 946 to 100 to 105. The first B scale runs from 100 to 112; the fortieth runs from 946 to 100 to 105. The first C scale runs from 100 to 334; the fortieth runs from 308 to 305.
The front of the frame is spanned by a brass pyramidal bar. A brass and metal mount with three thumbscrews is attached to the bar. The mount may be adjusted by height, and it slides along the bar. A magnifying glass was supposed to be positioned on the mount. A brass handle is in the case, but the round glass part is missing.
The frame is screwed to a mahogany base. A paper with instructions is glued to the top front of the base. The top back of the base is engraved: KEUFFEL & ESSER Co (encircling N.Y.); 4013 (/) 3419; TRADE MARK (below the K&E lion logo). A square off-white label inside the lid is printed: KEUFFEL & ESSER CO. (/) NEW YORK HOBOKEN, N.J. (/) CHICAGO ST. LOUIS SAN FRANCISCO MONTREAL (/) DRAWING MATERIALS, SURVEYING INSTRUMENTS (/) MEASURING TAPES (/) No. 4013 (/) SERIAL 3419. Writing on masking tape attached to the top and the front of the case has been covered with black marker. This writing may read in part 6825 and represent the inventory number at the Interstate Commerce Commission, which transferred the object to the Smithsonian in 1962. The Smithsonian catalog number is written on the top of the case in black marker: 321-789.
Keuffel & Esser Company of New York sold versions of the Thacher cylindrical slide rule from about 1883 until about 1950. There were two models, one with a magnifying glass (K&E model 1741 before 1900, K&E model 4013 after) and one without (K&E model 1740 before 1900, K&E model 4012 after). This is a model 4013; the serial number suggests it was manufactured around 1915. The marking on the core also no longer references W. F. Stanley, the English firm that originally manufactured the instrument for sale by K&E. Stanley continued to provide the engine-divided scales after K&E began making the rest of the instrument in 1887. K&E took over printing the scales in the 1910s. Model 4013 sold for $45.00 in 1913.
Compare markings on the core to MA*315663. See also MA*327886 and 1996.3079.01.
References: Wayne E. Feely, "Thacher Cylindrical Slide Rules," The Chronicle of the Early American Industries Association 50 (1997): 125–127; Catalogue of Keuffel & Esser Co. (New York, 1913), 294.
Currently not on view
date made
ca 1915
Keuffel & Esser Co.
place made
United States: New York, New York
Physical Description
wood (part material)
cloth (part material)
paper (part material)
brass (overall material)
overall: 18.8 cm x 60.5 cm x 21.3 cm; 7 13/32 in x 23 13/16 in x 8 3/8 in
ID Number
accession number
catalog number
Credit Line
Transfer from Interstate Commerce Commission
Rule, Calculating
U.S. National Government, executive branch
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Slide Rules
Data Source
National Museum of American History, Kenneth E. Behring Center


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