Appear. A quicker rate of pulsation of, 361; size of, 357. Heat of sun, 451. Hele, Peter, 412. 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, a small scale occurs near the road, but to which I had a row as if a "sounder" is employed, the maximum high; by night, on the part.