National Carbon Company Philadelphia Arc Light Carbon, 1886-1900

Carbon plates, like these, were used in arc lamps, the first widely used form of electric light in the late 1800s. The lamp's brilliant light, created by an electric arc between precisely spaced plates, effectively illuminated city streets, factories, and other large areas--though falling sparks could prove hazardous. Eventually, improvements in other types of arc discharge lamps made carbon plates virtually obsolete.