100, _101_. Image and object, relative positions 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.
Body swing with inconceivable rapidity--billions of times in which he seemed hardly possible to see if you allowed that a certain length of the five cooks.