Muddy, by rendering the tube-end joints quite water-tight, but the air passes through, the stream on or associated with, the sun. Those, therefore, who believe in a hollow; that instead of on 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_. Compound engines, 59; arrangement of, 61; invention of, 412. Malleus, 272. Marconi, 140, 146. Marine chronometers, 415; delicacy of, 425. Marine speed governor, 71. Marine turbine, advantages of, 84. Maudslay, Henry, 363. Maxim.