Production of electric light--Arc lights--Mechanism to regulate
carbons--Some lamps suitable for alternating current--When
carbons are consumed, light goes out--Arc lamps very complicated--
Jablochkoff candles--Arc formed between the carbons--Candles
require alternating current--Incandescent lamps--Vacuum formed
in lamps prevents combustion--Vacuum not perfect--Advantages of
incandescent lamps for house and ship lighting--Unaffected by
wind, and suitable for either continuous or alternating currents 19