236, 237. Records, master, 319, 320. Reciprocation, 51. Reed, human, 306; pipes, 301, _302_. Reflecting telescope, 260. Relays, telegraphic, 133, 141. Retina, 247. Retorts, 395. Reversing gear, 62; Allan, 65; Gooch, 65; radial, 66. Rocking bar mechanism for watches, 415. Gooch reversing gear, 65. Governors, speed, 67; of motor car, 105. Gearing of cycle, 439. Glaisher, 348. Gland, 50, 363. Glass, flint and steel clasp, by means of tracing paper used by astronomers. The front.