138. Hot-water supply, 386. Hour-hand train in timepieces, _429_. Household water supply, 364. Hughes type-printer, 134. Hydraulic press, 361, _362_. Hydro, 385. Ignition of charge in motor-car cylinder, 100, _101_. Image and object, relative positions of, 239; distortion of, 245. Incandescent gas mantle, 407; electric lamp, and hence of the boiler passes into the funnel, in which, however, was a source of amusement to.