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_, _437_. Yellow spot, in eye, 251. Spring balance for watches, 425. Rods of Corti, 274.