Chemical Slide Rule

Chemical Slide Rule

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Usage conditions apply
This chemical slide rule was designed by Raymond Harmon Ashley (ca. 1895-), a chemist teaching at the University of Maine. It was available by 1914, and said to be suitable for all the computations that would be carried out by a chemist or a chemical engineer.
Inscriptions on this example read "KEUFFEL & ESSER CO. N.Y." AND "PAT. 1,930,852" AND "MADE IN U.S.A."
Ref: R. Harmon Ashley, The Chemist’s Duplex Slide Rule (New York, 1923).
Adolf W. Keuffel, "Slide Rule," U.S. Patent 1,930,852 (Oct. 17, 1933).
Currently not on view
Object Name
Slide Rule, Chemical
date made
after 1933
Keuffel & Esser Co.
place made
United States
Associated Place
United States: New Jersey
overall: 320 mm x 51 mm x 12 mm; 12 5/8 in x 2 in x 1/2 in
overall: 12 1/2 in x 2 in x 7/16 in; 31.75 cm x 5.08 cm x 1.11125 cm
ID Number
catalog number
accession number
patent number
See more items in
Medicine and Science: Chemistry
Data Source
National Museum of American History
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