In 1880, Lewis Latimer, a draftsman and an expert witness in patent litigation, began working for the United States Electric Lighting Company run by Edison's rival Hiram S. Maxim. While working for Maxim, Latimer invented a process for making carbon filaments for light bulbs and helped install broad-scale lighting systems for New York City, Philadelphia, Montreal, and London. Latimer holds the patent for the electric lamp issued in 1881, and a second patent for the “process of manufacturing carbons” (the filament used in incandescent light bulbs), issued in 1882.