Seven (7) Keuffel & Esser (K&E) duplex slide rules, including two (2) 4160 Chemist's slide rules; one (1) N4081-5 20" Log Log Decitrig slide rule; one (1) 68-1200 Log Log Duplex slide rule; one (1) 4080-5 Log Log Trig slide rule; one (1) 4093-5 Log Log Vector slide rule; and one (1) 68-1308 20" Log Log Duplex Trig slide rule. All comprised of two-sided celluloid coated mahogany, with frameless plastic cursors with plastic edges held together with metal screws, and L-shaped metal end pieces. Maker's marks and model numbers, front and top edge of cursors, some with maker's marks and model top edges or obverse of slide rule. All housed in orange or black leather K& E cases, one (1) Chemist's slide rule includes original green cardstock box. Slide rules ranging in size from 12 1/2" to 22 1/4" L. Cases ranging in size from 12 7/8" to 23" L. All items 2nd-3rd quarter 20th century.

CONDITION: All items in overall good condition with wear, toning to celluloid, to be expected from age and manner of use. Some cases with black ink stamps or inscriptions from previous owners, general wear, one case with missing strap, some many not be original to slide rules. Model 4080-5 slide rule with replacement cursor.