Keuffel & Esser N4053-5 Polyphase Mannheim Simplex Slide Rule

This 20-inch mahogany one-sided slide rule is coated with white celluloid. The top edge is beveled and has a simply divided scale 20 inches long that is divided to sixteenths of an inch. The base has A, D, and K scales. One side of the slide has B, CI, and C scales; S, L, and T scales are on the other side. The A and B scales are divided logarithmically from 1 to 10 twice in the usual manner. The C and D scales are divided logarithmically once from 1 to 10 in the length of the scales in the usual manner. The CI scale is divided logarithmically from 1 to 10 the length of the scale, going in the opposite direction from the other scales. The K scale is divided logarithmically three times in the length of the scale, for use in finding cubes and cube roots. The S scale gives the sines of angles from less than 40 minutes to 90 degrees. The L scale is a scale of equal parts running from 0 to 10. The T scale gives tangents of angles from somewhat less than 6 degrees to 45 degrees.

The front edge has a simply divided scale 50 centimeters long that is divided to millimeters. The indicator is of the "frameless" glass style with plastic edge pieces and metal screws. 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. See also 1981.0933.05 and 1999.0254.01. The instrument fits in a cardboard case covered with black leather that fastens with a snap.

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 has the model number in red: < N4053-5 >. The left end of the other side of the slide and the scale in centimeters are marked with a serial number: 295836. The bottom edge of the indicator is marked: K&E.CO.N.Y. (/) PAT.8.17.15. The flap of the case is marked: K & E (/) POLYPHASE (/) SLIDE RULE (/) 4053–5. The snap on the case is marked: KEUFFEL & ESSER CO. (/) NEW YORK.

Keuffel & Esser sold an earlier form of this slide rule, with no beveled edge at the top, from 1913 through 1922. The new form of the instrument—with the beveled edge, the K scale on the base instead of on the bottom edge, and the centimeter scale on the bottom edge—sold from 1923 to 1953. The style of the indicator on this slide rule was in use from 1915 through 1934. Illustrations of the 4053 line of slide rules in K&E catalogs depict the patent date of June 5, 1900, from 1925 through 1934. Thus, this example likely dates to 1925–1934; the serial number suggests a date around 1930. Compare also to 1981.0922.05. For documentation, see MA.304213.05. The Interstate Commerce Commission discarded this rule as surplus material in 1963.

References: Willie L. E. Keuffel, "Slide-Rule" (U.S. Patent 651,142 issued June 5, 1900); Willie L. E. Keuffel, "Slide-Rule Runner" (U.S. Patent 1,150,771 issued August 17, 1915); Catalogue of Keuffel & Esser Co., 34th ed. (New York, 1913), 300; Catalogue of Keuffel & Esser Co., 35th ed. (New York, 1915), 300; Keuffel & Esser Co., Slide Rules & Calculating Instruments (New York, 1925), 6; Keuffel & Esser Co., Slide Rules & Calculating Instruments (New York, 1934), 6; Catalogue of Keuffel & Esser Co., 38th ed. (New York, 1936), 312; Ed Chamberlain, "Estimating K&E Slide Rule Dates," 27 December 2000, http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg.

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