Keuffel & Esser Co. Model 4081-3 Slide Rule Log Duplex Decitrig Math Ruler

This is a vintage Keuffel and Esser Log Log Duplex Slide Ruler, model 4081-3. The 1947 version, the 10" duplex slide rule was constructed on a mahogany wood frame with a celluloid overlay laminated surface. The rule is in good vintage condition with little graphic loss and some discoloration. The cursor has the frame only. Original brown leather case is included with initials on the exterior; in very good vintage condition. The case measures approximately 13" tall by 2.5" wide at top rim. Rule Details: Made in U.S.A. - Note: start of RED LL00, LL0 scales Patents listed on top of stock:Pats. R.E. 20,984; 1,930,852; 2,168,056; 2,170,144; Pat.Pend. Note: 1939-1947 Scale set, and "K&E" logo on slide Front Scale: Note: 5,10, 20 div/deg LL0, LL00, A [ B, T Cot, ST, S Cos ] D, DI, K Back Scale: L, LL1, DF [ CF, CIF, CI, C ] D, LL3, LL2