Vintage Keuffel and Esser Log Log Duplex Slide Rule Model 4081-3
This is a vintage Keuffel and Esser Log Log Duplex Slide Ruler, model N4081-3. Made in the late 1940's or early 1950's, 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 glass cursor is has minimal chips and scratches. Original green leather case is included and is in excellent condition. The case measures approximately 13" tall by 2.5" wide at top rim. Also included is a Slide Rule Manual No. 68 2047.
Rule Details: The left end of the slide is marked: 294410. The left end of the top and the bottom of the base are both marked: 410. The indicator is glass, with white plastic edges held together with metal screws. Front: LL02 LL03 DF = CF CIF CI C = D LL3 LL2 Rear: LL01 K A = B T SRT S = D L LL1 The top edge of the rule is marked: PATS. PEND. MADE IN U.S.A. N4081-3 LOG LOG DUPLEX DECITRIG ® COPYRIGHT 1947 BY KEUFFEL & ESSER CO. PATS. 2,500,460 2,168,056 2,170,144 2,285,722 2,422,649. T