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. Divided by W. F. Stanley, London, 1882. 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. A magnifying glass found within the case may be positioned on the mount. The mount may be adjusted by height, and it slides along the bar.
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 (/) 2151; TRADE MARK (below the K&E lion logo). A paper K&E label loose inside the case is also stamped: No. 4013 (/) Serial 2151. A plastic label inside the case lid is imprinted: KEUFFEL & ESSER CO. (/) NEW YORK (/) ST. LOUIS CHICAGO (/) SAN FRANCISCO. An index card with the letter V and a rectangle drawn in red pencil is also loose inside the case.
The model number and shape of the frame indicate this instrument was manufactured after 1900. The serial number and evidence that Stanley was still dividing the scales for K&E suggest a manufacturing date before 1910–1915. (K&E began to divide and print its own scales in the 1910s and subsequently dropped the reference to Stanley from the drum.) In 1906, the model 4013 Thacher cylindrical slide rule sold for $45.00.
The object was received with MA*271855.01.03, Directions for Using Thacher's Calculating Instrument (1907), which is a reprint of a booklet Edwin Thacher first published in 1884. The object was also received with a cardboard exhibit label, MA*271855.01.02, indicating that the Armour Institute of Technology donated the object to the Chicago Museum of Science and Industry, which in turn donated it to the Smithsonian in 1966 with a large supply of electrical apparatus. In Chicago, according to pencil markings on the case, label, and booklet, the object's museum catalogue number was 39.168.
See also MA*315663.
References: Edwin Thacher, Thacher's Calculating Instrument or Cylindrical Slide-Rule (New York: Van Nostrand, 1884); Wayne E. Feely, "Thacher Cylindrical Slide Rules," The Chronicle of the Early American Industries Association 50 (1997): 125–127; Catalogue of Keuffel & Esser (New York, 1906), 314.
Currently not on view
Object Name
calculating rule
slide rule
date made
Keuffel & Esser Co.
Physical Description
paper (scales material)
wood (base material)
brass (core, frame material)
glass (lens material)
overall: 18.5 cm x 68 cm x 20.8 cm; 7 9/32 in x 26 25/32 in x 8 3/16 in
place made
United States: New York, New York
ID Number
accession number
catalog number
Rule, Calculating
Science & Mathematics
Slide Rules
See more items in
Medicine and Science: Mathematics
Slide Rules
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of the Museum of Science and Industry, Chicago

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