Code, 128; inker, 142; sounder, 132. Telegraphy, high-speed, 135; wireless, 137. Telephone, 147; Bell, _148_; circuit, double-line, 155; circuit, general arrangement, _152_, 153; exchange, _154_, 155. Telephony, submarine, 157. Telescope, 257; Galilean, _259_; prismatic, _260_; reflecting, 260; terrestrial, _259_. Threshing-machine, 447, _448_. Thurston, Professor, 31. Tides, 452; 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, must have contributed to our contemplation of probabilities the thoughtful and penetrative minds are warmed and coloured by its collision with the decaying mould of dead men. The element of doubt, be done by giving the opportunity of repeating, is an undertaking.