Keuffel and Esser (K&E) slide rules, including one (1) Nordell Sewer Slide Rule; one (1) 4160 Chemist's 10" Mahogany Duplex slide rule; and one (1) 4088-3 Polyphase Duplex Slide Rule. All comprised of mahogany, with plastic or glass cursors with plastic or metal edges held together with metal screws. Duplex slide rules with two-sided coated celluloid 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 K& E cases. Slide rules ranging in size from 11 3/8" to 12 1/4" L. Cases ranging in size from 11 5/8" to 13" L. All items 1st-3rd quarter 20th century.

CONDITION: All items in overall very good condition with light wear, toning to celluloid, to be expected from age and manner of use. Cases with expected wear, surface grime. Orange case with stamp from previous owner to interior of flap.