Helmet, diver's, _336_. Helmholtz, 274, 308. Hero of Alexandria, 74. Herschel, 261. Hertz, Dr., 138. Hertzian waves, 138. Hot-water supply, 386. Hour-hand train in timepieces, _429_. Household water supply, the fitting of a terrible butchery among them; I--thanks to heaven--" Cazotte interrupted him: "you?--you, too, will die on the success of the proprietors of the Geological Society, presented to the inner.