On kites, 345; on sails, 346. Windmills, 375. Window, oval, in ear, 272; round, in ear, 272; round, in ear, 272. Wireless telegraphy, 137; advance of, 145; receiver, 140, 141; syntonic, 143; transmitter, 138, _139_. Yale lock, 436. Combustion, 26, 393; perfect, 28. Compensating gear, 107, _108_. Gear-box of motor car, 105. Gearing of cycle, 439. Glaisher, 348. Gland, 50, 363. Glass, flint and steel.