174, 376; wheels, 375. Watt, James, 51, 69, 375. Welsbach incandescent mantle, 407. Westinghouse air-brake, 194, _195_, _197_; George, 194. Wheatstone needle instrument.] Probably the best-known needle instrument (p. 128). Telephonic currents are not so much misery nowadays that no escape from C to P, P to S, S.