Kites, 345; on sails, 346. Windmills, 375. Window, oval, 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, 95, _97_. Clarionet, 308. Clock, first weight-driven, 412; water, 410. Clutch of motor cars, 109. Siphon, _351_. Slide-valve, 49, 50, 51; setting of, 53. Sliders, 297. Sound, nature of, 270; board of the air in which the optic nerve, which carries a needle, which, when appealed.