MAGXETISM AND ELECTRO-MAGNETISM.] INDEX TO VOL. I. 



1225 



Testing cyanide of potassium, 226. 

 Testing depositing liquids, 217. 

 Testing purity of silver, 236. 

 Testing silver, &c., in solutions, 236. 

 Theory of electro-deposition, 197. 

 Thermal conditions of deposition, 203, 



209. 



Tin and iron, electrical relations of, 221. 

 Tin salts and solutions, 220. 

 Tuck's patent silvering process, 225. 



Two metals in two liquids separated by 



a porous diaphragm, 199. 

 Type, to copy in copper, 231. 



VESSELS, depositing, 215. 

 Voltaic batteries, 186, et ieq., 214. 



WASHING silvered articles, 236. 

 Water needed in electro-deposition, 207. 

 Wires, connecting, 212, 216. 



Wiring articles for deposition process, 229. 

 Wood-cuts, to copy iu copper, 233. 

 Works of art, to copy, 229. 



ZINC, amalgamation of, 215. 



Zinc and copper batteries, 214. 



Zinc for batteries, 215. 



Zinc immersed in acids is dissolved, 201. 



Zinc salts, 219. 



Zinc solutions, 220. 



SECTION IV.-MAGNETISM AND ELECTRO-MAGNETISM. 



ACCIDENTAL magnetism, 245. 

 Alarm-bell, telegraphic, 261. 

 Allan's deep-sea cables, 272. 

 Allan's electro-magnetic engine, 252. 

 Allan's method of telegraphy, 271. 

 Allan's telegraph alphabet, 273. 

 Alphabet, telegraphic needle, 201. 

 Alphabetical telegraphs, 269. 

 Alphabetical telegraph, Wheatstone's 



private, 273. 



American telegraphic systems, 268. 

 Apparatus required for electro-magnetic 



experiments, 247. 

 Artificial magnets, 243. 

 Atlantic cable, causes of its failure, 265. 

 Atlantic, the, cable, 264. 

 Atmospheric currents and the telegraph, 



262. 



Atmospheric influence on the needle, 246. 

 Attraction and repul-ion exhibited by a 



Uhumkorf's coil, 256. 

 Attraction, magnetic, 213, 244. 

 Attractive power of electro-magnets, 251. 

 Aurora borealis imitated by the Rhumkorf 



spark in racuo, 256. 

 Aurora borealis, influence of, on the 



needle, 245. 



BAINS' electro -chemical printing tele- 

 graph. 268. 



ill's copying telegraph, 2G7. 



Balloon electric telegraph*, 274. 



Barlow's apparatus for explaining the 

 earth's magnetism, 249. 



Bar-magnets, 211. 



liattrrics, voltaic (See p. 1223). 



lirll. the telegraphic alarm. 201. 



Birds and telegraph wires, 262. 



CABLE, Allan's deep-sea, 272. 



. Atlantic, 264. 



Cable, coatings of a submarine, 203. 

 Cable, construction, &c., of a submarine, 



263. 



Cb!e, insulation of a submarine. 263. 

 Cable, size and number of wires of a, 



2f>3, - 

 Cable, submarine, accidents arising to, 



264. 



Cable, submersion of a submarine, 264. 

 Cables, shore ends of, 261. 

 Cables, submarine, action of intense 



currents on, 265. 

 Cable*, -submarine, statistics of various, 



264. 

 Cables, various submarine (see, also, 



names of the stations), 264. 

 Carbon, effects of on iron, in regard to 



magnetic induction, 249. 

 Chemical effects of induced currents, 255, 



2J7, 258. 



Chemical printing telegraphs, 266. 

 Clocks, electro-magnetic, 253. 

 Cobalt, magnetic properties of, 245. 

 Coil-machine, shock from a, 254. 

 Coil-machine, the electro-magnetic, 253. 

 Coil, RhumkorPs, 255. 

 Coil, the electro-magnetic, 249. 



Tot, 1. 



Coils for telegraphic purposes, 200. 

 Coils, primary and secondary, 253. 

 Commercial importance of the telegraph, 



263, 270. 

 Compass, action of the iron and cargo of 



vessels on the, 246. 

 Compass, local and accidental disturbances 



of the, 246. 



Compass, the mariner's, 245. 

 Compass, variation of the, 245, 246. 

 Compasses, adjustment of ships', 246. 

 Compound magnets, 244. 

 Conductor, the earth used as a conductor, 



262. 



Contact-breakers, 254, 258. 

 Copper wire as molecularly affected by ] 



electric currents, 204. 

 Copper wire, electrical resistance of, 250. 

 Copying telegraph, Bakewell's, 267. 

 Core of iron in the coil. machine, 254. 

 Currents, intense, peculiar action of, on 



submarine cables, 265. 

 Currents of electri-ity influence the 



magnetic needle, 247. 

 Curves, magnetic, 215. 



DECLINATION (see Variation), 245. 

 Deflection of the needle by an electric 



current, 247, 259. 

 Dia-magnetics and magnetics, 271. 

 Dia-magneti?m, 270. 

 Dia-magnetism and gravitation, 271. 

 Dia-magnetism and motion. 271. 

 Dia-magnetism of gases, liquids, metals, 



4c., 271. 



Dipping-needle, the, 245. 

 Diurnal variation of the needle, 245. 

 Divergence of the magnetic needle by 



electricity, 247. 

 Double-needle telegraph, 261. 

 Dover and Calais cable, 261. 

 Dover and Ostend cable, 264. 



EARTH-CURRENTS, effect of, on the 



needle, 262. 



F.artli, magnetic poles of the, 215. 

 Earth, magneto-inductive power of the, 



215. 



Earth, the, used as a conductor, 262. 

 Earth's magnetism, electro-magnetic 



theory of the, 249. 



Electric and magnetic phenomena, 247. 

 Electric current, action of, on the magnetic 



needle, 247. J* 



Electric harmonium, t^K 

 Klectric telegraph, the7llj9. 

 Electric telegraph, various uses of the, 263. 

 Klectric time-bills, 270. 

 Electricity and magnetism, mutual relation 



of, 257. 



Electricity as a motive power, 251. 

 Electricity, induction of, by magnetism, 



257. 



Electrified wire, polarity of an, 218. 

 Electro-chemical printing telegraphs, 



Bains', 267, 268. 

 Electro-magnetic and electric induction 



analogous, 253. 



Electro-magnetic clocks, 253. 



Electro-magnetic coil-machine, 254. 



Electro-ma;netic coil, the, 249. 



Electro-magnetic engines, 251. 



Electro-magnetic induction, 249. 



Electro-magnetic induction, secondary, 

 253. 



Electro-magnetic phenomena, illustra- 

 tions of, 248. 



Electro-magnetic rotation, 249. 



Electro-magnetic theory of the earth's 

 magnetism, 249. 



Electro-magnetism, 247274. 



Electro-magnets, 249. 



Electro-magnets, horse-shoe, 250. 



Engines, electro-magnetic, 251. 



Equator, the magnetic, 245. 



FIRKS, detection of, by Siemen's electric 



thermometer, 274. 

 Fitzrny's storm signals, 269. 

 Fogs, influence of, on the needle, 246. 

 Fractional electricity and the induced 



current of a RhumkorPs coil, analogies 



between, 257. 



Froment's alphabetical telegraph, 269. 

 Froment's electro-magnetic engine, 252. 



GASSIOT'B vacuum experiment with 



Rhuinkorf s coil, 256. 

 Gravitation and dia-magnetism, 271. 

 Gutta-percha as an insulator for submarine 



cables, 263. 



HEATED air extends the length of a spark, 



255. 

 Holmes' magneto-electric light machine, 



258. 



Horse-shoe electro -magnets, 250. 

 Horse-shoe magnets, 244. 



INDIA-RUBBER as an insulator for sub- 

 marine cables, 263. 



Induced currents analogous to those of 

 frictional electricity, 257. 



Induction, electro-magnetic, 219. 



Induction, magneto-electric, 257. 



Induction in submarine cables, 265. 



Induction, secondary electro- magnetic, 

 253. 



Insulation of land-telegraph wires, 262. 



Insulation of submarine cables, 263. 



Intense currents, peculiar action of, on 

 submarine cables, 265. 



Intensity of magnetic force, 244. 



Iron, magnetism of, induced by art 

 electric current, 249. 



Iron, soft, cannot be permanently mag- 

 netic, 243. 



KEEPERS of magnets, 244. 



LATINO a submarine cable, 265. 

 Length and resistance of wires, 250. 

 Leyden jar, charged, analogous to the 



state of a submarine cable, 265. 

 Leyden jar, to charge, by a RhumkorPt 



coil, 257. 



