INDEX.

Preece, Sir William, 145. Primary winding of induction coil, 122. Pump, air, 340; bucket, 352, 353 ; force, 354; most marvellous, 355; Westinghouse air, 199. Railway brakes, 187; signalling, 200. Rays, converging and diverging, 256 ; heat, concentrated by lens, 232 ; light, 232, 235, 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, 425. Rods of Corti, 274.