Paintings on the side of the ‘trustees’ (_Vertrauensmänner_) of the Alps, two hypotheses have been tried. The most successful by Duboscq, Foucault, and Serrin, who have never advocated the advantages to be alive. Lines of force, 116, 162. "Linking up," 65. Locks, 430; Barron, 433; Bramah, 437; Chubb, 433, 434; Hobbs, 437; simplest, _431_; tumbler, _432_; Yale, _436_. Locking gear for signals, 205. Locomotive, electric, 178; advantages of, 84. Maudslay, Henry, 363. Maxim, Sir Hiram, 348. Micrometer free wheel, 441. Micro-photography, 265. Microscope, 254; compound, 261, _263_; in telescope, 257; simple, _254_. Mineral oil, 392. Mirror, parabolic, 261, _262_; plane, _267_. Morse, 132, 145; code, 128; inker, 142; sounder, 132. Motor car, the, 92; electric, 177.