INDEX.

self-starting, 42. Interlocking of signals, 204, 222. Internal-combustion engine, 87. Iris of eye, 249; stop, 249. Kelvin, Lord, 158. Keyless winding mechanism, 425, 426 , 428. Kite, 345. Lamp, arc, 182; how it works, 392; incandescent, 179; manufacture of incandescent lamps, 180. Lap of slide-valve, 57 , 59. Larynx, 306. Laxey wheel, 380 , 381. Leads, 208. Lenses, 231; correction of for colour, 240, 241 ; focus of, 236; rectilinear, 245 ; spherical aberration in, 243. Levers, signal, colours of, 208. Limit of error in cylinder, 52. Light, electric, 179; nature of, 230; propagation of, 231.