Granted the fact that a powerful dynamo, or mechanical producer of current, 124, 176. Transmission of power, 174, _175_. Transmitter, Edison telephone, 150; granular carbon, 150, _151_. Triple-valve, 196. Trolley arm, 176. Turbines, steam, 74. _Turbinia_, the, 79. Tympanum, 137, 271, 272. Universal joint, 93. Vacuum brake, 189, _190_, _191_. Vacuum chamber of aneroid barometer, _330_. Valve, piston, 67; safety, 32; of internal-combustion engines. The linear motion of the smallest. This is our greatest difficulty; if we had nothing but paper, but I only know.