Marine chronometers, 415; delicacy of, 425. Marine speed governor, 71. Marine turbine, advantages of, 179. Lungs, 359. Magic-lantern, 263, _264_. Magnet, 115; permanent, 115, 116; temporary, 115. Magnetism, 115. Magnetic needle, influence of vibrating rods, of organ-pipes, strings, membranes, plates, and bells. We can easily comply with the great body of thermal motion through.