Artifact Details Title Duplex Slide Rule Catalog Number X170.83B Type Physical object Date 1902 Manufacturer Keuffel & Esser Company Place Manufactured U.S. Identifying Numbers Other number OCT.6.1891 patent date Dimensions 3/8 x 11 x 1 1/4 in. Category Pre-computer/slide rule Subject Hand calculation; Analog; Oughtred, William Credit Gift of Tom McIntyre Lot Number X170.83A-C