INDEX. 



Absorption of water, 385. 



Alarm, Cavallo's, 10; Kramer's, 72; 

 Reusser's, 10 ; Siemens', 80 ; Soin- 

 mering's, 19. 



Alloy unit, 338. 



Alloys, conducting powers of, 268. 



Alphabet, Gauss and Weber's, 31; 

 Morse' s,87; Stoehrer's, 175; Wheat- 

 stone's, 49, 50. 



Alum battery, 228. 



Amalgamation, 332. 



Amalgamated zinc, 231. 



Amber, 1. 



Ampere, deflection, 21 ; telegraph, 23. 



Annealed metals, 269. 



Apparatus for cable tests, 294. 



Arago, 249. 



Astatic needles, 243 ; faults of, 244. 



Atlantic cable, 243, 348. 



Atmospheric electricity, 202. 



Attraction and repulsion, 2. 



Automatic printing, 166. 



Bain's telegraph, 176. 



Bakewell's telegraph, 179. 



Balance, Wheatstone's, 290, 292 ; Bri- 

 tish Association, 306 ; bisected wire, 

 309. 



Battery, alum, 228. 



Battery, commutator, 104 ; Daniell's, 

 221 ; earth, 230 ; galvanic, 220 ; 

 effects of galvanic, 218 ; Grove's, 

 327, 328; Kramer's, 224; Meid- 

 inger's, 224; Siemens', 226; sul- 

 phate-mercury, 229 ; Varley's, 227, 



Beaudoin and Digney, 122. 



Betancourt's telegraph, 10. 



Bianchi's lightning-guard, 213. 



Bisected wire, 309. 



Bonelli's telegraph, 182. 



Boucherie's process, 185. 



Borggreve's commutator, 100. 



Break, 396. 



Breguet's telegraph, 65 ; lightning- 

 guard, 209, 211. 



Brett's cable, 241. 



Bright, insulator, 189 ; preserving 

 posts, 187; testing joints, 371. 



B. A. balance, 306 ; unit, 338. 



Cable, Atlantic, old, 341 ; Atlantic, 

 new, 348; Carthagena-Oran, 346; 

 Dover-Calais, 341 ; Dover-Ostend, 

 341 ; in the ship, 388 ; Malta- 

 Alexandria, 344 ; Persian Gulf, 345 ; 

 Red Sea, 343; self- heating of, 373; 

 tests, 350 ; joints, 368. 



Calibrating tubes, 330. 



Carlisle, decomposition, 18. 



Cavallo's telegraph, 10. 



Charge in overland wires, 200 ; in sub- 

 terranean wires, 111. 



Charge, measurement of, 301 ; along 

 the line, 410. 



Chatterton's compound, 352. 



Checking action, 31, 249. 



Chemical theory, 17. 



Chemical telegraph, Bain's, 176; Bake- 

 well's, 179; Bonelli's, 17; Davy's, 

 42; Gintl's, 156, 180; Maison- 

 neuve's, 179 ; Morse's, 40. 



Chloride of zinc, 186. 



Circuit, simple Morse, 84 ; for two 

 stations, 93. 



Circuit, electric, 206 ; galvanic, 216 ; 

 local, 92 ; shunt, 286. 



Classification, 1. 



Clarke's insulator, 191 ; joint testing, 

 371. 



Clocks for paying out tests, 399. 



Closed circuit, 148. 



C. M., 6 



Combination of G. P. and I. R., 387. 



Commutator, battery, 104; Borg- 

 greve's, 100; for three lines, 102; 

 intermediate, 95 ; Nottebohms, 96 ; 

 Siemens', 98. 



Compensation method, 320. 



Conducting power, 264 ; alloys, 268 ; 

 annealed metals, 269 ; cable con- 



