High, 453; neap and spring, 455. Timbre, 285. Tompion, Thomas, 412. Torricelli, 325. Trachea, 306. Train staff signalling, 216; single, 216; and ticket, 217; electric, 218. Transformation of current, 124, 176. Transmission of power, 174, _175_. Transmitter, Edison telephone, 150; granular carbon, 150, _151_. Triple-valve.