Range Finder, 80cm

During the First World War, the 80cm Range Finder was an essential tool for field artillery units. Before America’s involvement in the war, most optics originated from European countries, with Germany being the primary producer of optic glass. Artillery technology had significantly advanced since the Napoleonic era when cannons were aimed mainly by eyesight. The development of improved projectiles in the early 20th century extended the range of artillery beyond the horizon, necessitating precise aiming instruments capable of accurate measurements and durable enough to withstand the recoil from firing artillery.

By the time the United States entered the war, only three domestic companies could produce glass and optics. Among these, Bausch & Lomb Optical Co., based in Rochester, NY, manufactured most of the glass used in optics during the war and all Range Finders. Anticipating an increased demand for optics, Keuffel & Esser Co. in Hoboken, NJ, secured contracts to produce Range Finders, though the Army canceled these contracts before any were delivered.[1] By the end of hostilities on November 11, 1918, Bausch & Lomb had supplied 2,167 Range Finders to the frontlines, with an additional 2,600 delivered by February 20, 1919.[2]

The range finder was mounted atop a fire-control tripod made by the National Cash Register Co. in Dayton, Ohio.[3] Each metal component of the tripod featured a part number, and the top adapter bore a US Ordnance acceptance stamp. The tripod’s design included three spiked metal poles housed within wooden legs, adjustable up to 60 inches in length.