DescriptionI-scale [rule], plotting, flat, metric, 30 centimeters long, made for U.S. Government (Navy?) by Keuffel & Esser Co., New York, no date, circa 1930s-1940s. Degame (stated on envelope) wood with black printed graduations, both edges beveled, overall 12-1/2" (31.5 cm) long x 1-5/16" wide x 3/16" thick; bottom is blank. With: original paper sleeve (treated, apparently water-resistant or water proof) imprinted with description and product information plus an inner plain paper sleeve. Imprinted in the center is: U.S. | Keuffel & Esser Co. N.Y. Top scale identified at left: 1:10,000 Meters Rule is inverted for using scale on other edge - 1:50,000 Meters Text printed on paper sleeve: P.O. #4903726-27; REQ. N-EP-6704 I-SCALE, PLOTTING, FLAT, METRIC LENGTH 30 CM, SCALE 1/10,000 - 1/50,000; MADE OF DEGAME WOOD WITH PLAIN EDGE AND PRINTED GRADUATIONS SNL #18-6900.300-110; ITEM #3. It has not been established for what agency this scale was made or its actual use. It has been reputed, but not verified, that this type of scale was used in the European Theatre of operations during World War II by the U.S. Army (Marines, Navy?) for reading charts (maps); additional comments have been seen that it was for intelligence operations. K&E had their main office and factories in Hoboken when it was made.