This "shoebox" gunsight prototype was built by Dr. Charles S. Draper in 1941. For many years, U.S. anti-aircraft guns had used fixed sights and their crews had difficulty in tracking and hitting fast-flying planes. The "shoebox" gunsight was placed directly on the gun. Gun crews would hold its reticle on the target and the gun barrel or barrels would quickly and continuously move in the right direction to permit the target to be hit. The "shoebox" gunsight prototype directly led to the development of the U.S. Navy's Mark 14 gunsight during World War II, which proved very effective in helping to destroy enemy airplanes. This artifact was donated to the Museum by Dr. Draper in 1974.