DescriptionSlide rule model no. 8858, 10" Mannheim, made by Keuffel & Esser Co., 1942. Boxwood with white painted surfaces on front and rules; scales printed in black; one piece celluloid cursor; back is natural with clear varnish and text printed in black as below. The model number only appears on the back. No serial number. With: original one-piece printed carton This item was a special item, a loaner during the beginning of World War II, which was not listed in the K&E catalogue. It is essentially the same as the 4058. Reversible slide: front scales, B, C; back scales, S, L, T. Marked on front "Keuffel & Esser Co., N.Y., Made in U.S.A." K&E had its general office and factories in Hoboken, N.J. where this item was made. Text printed on back: No. 8858 Slide Rule. Loaned on deposit of $1.00 by Keuffel & Esser Company to meet a temporary shortage caused by defense orders. This deposit will be accepted as part payment toward the purchase of a standard K & E slide rule through your regular dealer before July 1, 1942. This slide rule belonged to a F.D. Casey, 590 Fort Washington Ave., New York, New York, as recorded by this person on the box back.