DescriptionFolding pocket rule, 3 foot, made by Keuffel & Esser Co., New York, no date, circa 1893-1927. Stamped metal (tempered spring steel), 12 fold, 3/8" high x 4-3/16" wide (closed); graduated in inches and sixteenths. Stamped on first section: Keuffel & Esser Co. New York. Pat. April 25, 1893. No stock number (corresponds to number 1727.) This item does not appear in the 1927 catalog when only wooden folding rules were still being offered. K&E had its primary manufuacturing in Hoboken during this period. U.S. patent number 496,123 was issued to W.L.E. Keuffel in 1893 for "folding rule joints" of a "Zig-Zag Rule". K&E catalogues stated it as "spring joint steel rules."