Scope and ContentManual: How to Take Care of Your K&E Slide Rule; Duplex. Published by Keuffel & Esser Co., New York & Hoboken. Copyright 1944,1949. Issued in box with K&E slide rule model N4080, objects 2009.006.0137, made circa 1955-1957. Pamphlet, 2" x 4" wide, [12] pages. Stock code on page [12]: 67188. Back cover has Keuffel & Esser Co. imprint with product lines and branch offices. Note that it mentions "optical tooling," but it is not yet renamed "Optics and Metrology." Main office and factories were in Hoboken in this period.