Calcium carbide may be made by heating an intimate mixture of finely divided coke or carbon and lime in an electric furnace, using a current of from 4,000 to 5,000 amperes. The furnace used by Willson in America consists of an outer coating of firebrick lined with carbon or graphite, a tap hole being placed near the bottom; the furnace is covered with carbon plates, through which passes a thick carbon rod reaching nearly to, but not touching, the bottom of the furnace; the carbon rod and the inner carbon layer are connected to the dynamo. 1,2001b. of fine coaldust and 2,0001b. of quicklime yield 2,0001b. of carbide in twelve hours.