This file consists of Edison's reply to Maxim's answer in his appeal before the Examiners-in-Chief in the case of Maxim v. Edison, which involved conflicting claims over the incandescent lamp. Edison's first patented electric lamp (U.S. Patent 214,636) had a platinum filament with a thermostatic current regulator to prevent the metal burner from overheating. The patent was placed in interference with an application by inventor Hiram S. Maxim (1840-1916), who at the time was chief engineer of the United States Electric Lighting Co. In February 1881 the Patent Office ruled in favor of Maxim. Edison appealed twice, but the Commissioner of Patents affirmed the ruling in late July or early August. By that time, neither the Edison Electric Light Co. nor the United States Electric Lighting Co. foresaw any practical use for the invention.

Courtesy of the National Archives.