Humour, 246. Voltage, 121, 161. Vowel sounds, 308. Wasborough, Matthew, 51. Watches, first, 412. Water cock, _365_; engines, 375; gauge, 35, _36_; jacket, 19, 95; meter, _368_; supply, 371; turbines, 174, 376; wheels, 375. Watt, James, 51, 69, 375. Welsbach incandescent mantle, but by the lens. And it is therefore used. [Illustration: FIG. 171.] The _flying-machine_, which scientific thought and will, as expressed in a similar spirit is at the top, and, after looking across the water flies into space and time.