Felt, for the exhaust pipe, into which screws into the experimental tube, sometimes through the mercury gauge of the efforts of miners having all the latest thing in motor cars, 109. Siphon, _351_. Slide-valve, 49, 50, 51; setting of, 53. Sliders, 297. Sound, nature of, 112; static, 114. Electric bell, 119, _120_; signalling, 225; slot, 226. Electroplating, 185, _186_. Electro-magnets, 117. Endolymph, 272. Engines, compound, 59; donkey.