Keuffel & Esser 4083-3 Log Log Vector Duplex Slide Rule

This two-sided ten-inch mahogany slide rule is coated with white celluloid and held together with metal end pieces. On one side, the base has LL02, LL03, DF, D, LL3, and LL2 scales, with CF, CIF, CI, and C scales on the slide. The right end of the slide is marked in red: © (/) K + E. On the other side, the base has Sh1, Sh2, Th, A, D, DI, LL01, and LL1 scales, with B, T, SRT, and S scales on the slide. The trigonometric scales are divided into degrees and into decimals. The left end of the slide has a serial number: 344425. The left ends of both parts of the base are marked: 425. A glass indicator has plastic edges and metal screws. Compare to MA.335483.

The top edge of the rule is marked: PATS. PEND. MADE IN U.S.A. 4083-3 LOG LOG DUPLEX VECTOR ® COPYRIGHT 1947 BY KEUFFEL & ESSER CO. PATS. 2,500,460 2,168,056 2,170,144 2,285,722 2,422,649. These patents were issued between 1939 and 1950. They dealt with the arrangement of scales on a slide rule, in particular so that the user could solve multistep problems without having to write down intermediate settings, and with the placement of a legend to make placing the decimal point easier. See 2007.0181.01 for patent citations.

There is no case. Keuffel & Esser of New York used this set of scales on this model number from 1955 to 1962. The serial number is consistent with a date earlier in this time frame. The company donated this example to the Smithsonian in 1961. The rule sold for $24.50 in the 1950s.

References: Clark McCoy, "Collection of Pages from K&E Catalogs for the 4083-3 Family of Slide Rules," http://www.mccoys-kecatalogs.com/KEModels/ke4083-3family.htm; Ed Chamberlain, "Estimating K&E Slide Rule Dates," 27 December 2000, http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg; K + E Catalog, 42nd ed. (New York: Keuffel & Esser Co., 1954), 280–281.

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