DescriptionK&E Mechanical Lateral Adjuster, model 5171, made by Keuffel & Esser Company, (NY & Hoboken), no date, circa 1955-1965. Machined metal (steel & bronze?) and brass; 13" long x 4-3/4" wide x 3" high. Top has 3-1/2" x 8 male thread to mount a transit, jig transit or level; bottom has the same female thread for mounting on tripod or instrument stand. Marked "K&E, Keuffel & Esser Co." on top of slide at end with adjusting screw knob. Model number has not been found on item. This item is part of the Optical Tooling Equipment category as found on page 386 of the 42nd edition catalog, 1954. The appearance of the object here varies from the depiction in the catalog, but that is not uncommon. The mounting plate can be manually adjusted for a travel of 5-1/2" side to side and locked with a knob. A micrometer screw (knob at end) allows for fine adjustments. The device is part of line of tools for work in several industries, including manufacturing where lining up jigs, such as for aircraft fuselage or wing assembly, requires precision. Keuffel & Esser Co. main office and factories were in Hoboken in the period when this item was made.