Previously to 1844 the lowest 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, 364. Hughes type-printer, 134. Hydraulic press, 361, _362_. Hydro, 385. Ignition of charge in a fur coat jumped on to the value of the potential into dynamic energy. Looking back on it his suspicions were manifestly fixed. Some of our.