Ten (10) Keuffel & Esser (K&E) Slide Rules. 1st item: K&E 4061 Polyphase Duplex slide rule. Comprised of two-sided celluloid coated mahogany, with frameless glass cursor with plastic edges held together with metal screws, and L-shaped metal end pieces. Maker's marks and model number, front and top edge of cursor. Includes one (1) brown leather K & E case. Slide rule: 7 1/4" L. Case: 7 5/8" L. 2nd item: K&E 4061T Polyphase Duplex slide rule. Comprised of two-sided celluloid coated mahogany, with glass "clamshell" cursor in a brass frame, and L-shaped metal end pieces. Maker's marks and model number, front and top edge of cursor. Includes one (1) brown leather case. Slide rule: 7 1/4" L. Case: 7 5/8" L. 3rd item: K&E 4068 Duplex slide rule. Comprised of two-sided celluloid coated mahogany, with glass "clamshell" cursor in a brass frame, and metal end pieces. Maker's marks, front. Includes one (1) brown leather case. Slide rule: 9 7/8" L. Case: 10" L. 4th item: K&E 1747 5 Inch Mannheim slide rule. Comprised of one-sided celluloid coated mahogany, front, laminated paper label, back. Maker's marks, front. 5 1/2" L. 5th item: K&E 4087 T slide rule, duplex with Trig Scales. Comprised of two sided celluloid covered mahogany with metal framed glass cursor. Maker's marks and patent number, bottom of the base. Housed in a K & E leather case. Slide rule: 22 1/8" L. Case: 22 3/4" L. 6th item: K&E 4051 Mannheim slide rule, comprised of one sided celluloid covered mahogany with 2 metal framed glass cursors. Maker's marks and patent numbers, top. Housed in a K & E original leather case. Slide rule: 20 1/2" L. Case: 20 3/4" L. 7th item: Keuffel & Esser 4051 Mannheim slide rule, comprised of one sided celluloid covered mahogany with 1 metal framed cursor. Maker's marks, top. Housed in a black K & E early case. Slide rule: 20 1/2" L. Case: 20 3/4" L. 8th item: K&E 4051 Mannheim slide rule, comprised of one sided celluloid covered mahogany with metal framed cursor. Maker's mark to cursor. Housed in a black K & E early case. Slide rule: 20" L. Case: 20 3/4" L. 9th item: K&E 4051 Mannheim slide rule, comprised of one sided celluloid covered mahogany with brass-framed cursor. Maker's marks to cursor. Housed in a black K & E early case. Slide rule: 20" L. Case: 20 3/4" L. 10th item: Early Keuffel & Esser Mannheim slide rule, comprised of one sided celluloid covered mahogany with brass chiseled cursor. Maker's marks, top and cursor. Housed in a black K & E early case. Slide rule: 10 3/8" L. Case: 10 5/8" L. Provenance: Private West Tennessee Collection. Condition: All items in overall good condition with wear to be expected from age and manner of use. Areas of tarnish to brass cursor frames and metal end pieces. 1st item: Edge of cursor with two 1/4" areas of loss to glass. 2nd item: Cursor with 3/4" x 7/8" area of loss to glass. 3rd item: Toning to celluloid. Case with wear, stitching is not present to one side. 4th item: Cursor is not present. Ink inscription from previous owner, back.