CONTENTS. 
yn 
machinery, 163—Brakes and dynamometer, 164—Choice of route* 
166—Laying shore cables, 168—Causes of accidents to cables* 
170—Physical causes, 170—Destructive animals, 173—Accidental 
mechanical causes, 177—Repairs to cables, 178—Taking up 
machinery, 179—Appliances for grappling and buoying cables, 180— 
Methods of repairing cables, 183—Process of recovering the Atlantic 
cable from deep water, 186. 
CHAPTER IV. 
Sources of Electricity .194 to 210 
Voltaic batteries, 194—Daniell’s, Siemens’, 195—Minotto’s, 198—- 
Thomson’s, 199—Callaud’s, 201—Grove’s, 203—Leclanche’s, 204— 
English common battery—Magnetic properties of a wire connecting 
the poles of a battery, 206—Electrical resistance, 207—Various 
methods of connecting the cells of a battery, 208—The multiplier or 
galvanometer, 209—Electro-magnets, 210. 
CHAPTER V. 
Telegraphic Apparatus. 211 to 263 
The single-needle instrument, 211—Various forms of manipulators or 
transmitting keys, 214—The mirror galvanometer, 215—The dis¬ 
tributor, 216—The condenser, 218—Thomson’s siphon recorder, 221 
—Adjustments : Of the paper, 222—Of the siphon and signal coil, 
223—Of the electrical mill, 224—Smith’s commutator, 225—Morse’s 
apparatus, 228—Relays, 230—Siemens’ polarized relay, 232—Morse 
key, 234—English post-office key, 235—Wheatstone’s automatic 
apparatus, 237—Mode of connecting up the whole telegraphic appara¬ 
tus at a terminal station, 244—Hughes’ printing telegraph, 246—The 
“sounder,” 250—Duplex telegraphy, 231—Duplex telegraphy with 
submarine cables, 256—The artificial line, 257—Accessory apparatus* 
260—Earth plates, 260—Lightning conductors, 261. 
CHAPTER VI. 
Position of Faults . 264 to 270 
Derangements, 264—Causes of faults, 264—Instrumental tests, 265- 
Calculation of the position of a fault, 267. 
