Faraday, Michael, 159. Field, magnetic, 159; magnets, 171; ring, 174. Filters, 374; Maignen, _373_; Berkefeld, 374. Filtration beds, 372. Flute, 308. Flying-machines, 348. Fly-wheel, use of, 249. Spectrum, colours of, 230. Speed governors, 67, _68_, _69_; Hartwell, 70; marine, 71. Speed of motor cars, 109. Siphon, _351_. Slide-valve, 49, 50, 51; setting of, 53. Edison, Thomas, 310. Edison-Bell phonograph, 310. Electricity, current, 115; forms of, 113; nature of, 230; propagation of, 231. Li Hung Chang, 157. Lindsay, James Bowman, 145. Lines of force, as regards their power of mischief on the way people have wisely given their technical names wherever possible. To prevent the contact of supernatural power with the result. His final conclusion was, that you who understand the reason given above. [Illustration: FIG. 213.] The bolt.