Chemical Slide Rule


Chemical slide rule designed by Raymond Harmon Ashley (ca. 1895-), a chemist teaching at the University of Maine. The form 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).

Date Made: after 1933

Maker: Keuffel & Esser Co.

Location: Currently not on view

Place Made: United States

See more items in: Medicine and Science: Chemistry


Exhibition Location:

Data Source: National Museum of American History

Id Number: CH.337236Catalog Number: 337236Accession Number: 1979.0768Patent Number: 1,930,852

Object Name: Slide Rule, Chemical

Measurements: overall: 320 mm x 51 mm x 12 mm; 12 5/8 in x 2 in x 1/2 inoverall: 12 1/2 in x 2 in x 7/16 in; 31.75 cm x 5.08 cm x 1.11125 cm


Record Id: nmah_3026

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