Keuffel & Esser N4053-3 Polyphase Mannheim Simplex Slide Rule

This ten-inch one-sided mahogany slide rule is coated with white celluloid. The top is beveled and bears a scale of nine inches whose ends may have broken off. The base has A, D, and K scales. The slide has B, CI, and C scales on one side and S, L, and T scales on the other side. The indicator is glass with plastic edges held together with metal screws. The top plastic edge is broken. The front edge of the rule has a scale of 25 centimeters. A paper table of equivalents and slide rule settings, based on U. S. Bureau of Standards Circular No. 47, is pasted to the back of the rule. Compare the table to 1999.0254.01.

The top of the base is marked in red: PAT. JUNE 5, 1900; KEUFFEL & ESSER CO. N.Y.; MADE IN U.S.A. The right end of the slide is marked in red: < N4053-3 >. The left end of the other side of the slide and the scale of centimeters have the serial number: 350305. The top of the base and under the slide are scratched with the initials: PML. The bottom plastic edge of the indicator is marked: PATENT 2,086,502, with K&E CO. N.Y., on the back of the edge.

Keuffel & Esser of New York sold this slide rule as model N4053-3 from 1925 through 1953. Illustrations in K&E catalogs include the patent date of June 5, 1900, from 1925 through 1934. The serial number suggests the rule was made closer to 1934. However, the patent on the indicator was issued in 1937, suggesting that this part was replaced after the rule was purchased. Compare to 1981.0922.08.

William J. Ellenberger (1908–2008) donated this object. He studied electrical and mechanical engineering at The George Washington University between 1925 and 1934. He then worked for the Potomac Electric Power Company and the National Bureau of Standards. During World War II, he served in the U.S. Army Signal Corps. He was a civilian construction management engineer for the army from 1954 to 1968, when he became a private consultant.

References: Adolf W. Keuffel, "Runner for Slide Rules" (U.S. Patent 2,086,502 issued July 6, 1937); Clark McCoy, "Collection of Pages from K&E Catalogs for the 4053 Family of Slide Rules," http://www.mccoys-kecatalogs.com/KEModels/ke4053family.htm; Ed Chamberlain, "Estimating K&E Slide Rule Dates," http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg; Wayne E. Feely, "K & E Slide Rules," The Chronicle of the Early American Industries Association 49, no. 5 (June 1996): 50–52; "The GW Engineering Hall of Fame 2006 Inductees," http://www.weas.gwu.edu/ifaf/hall_of_fame_inductees_2006.php.

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