INDEX TO VOLUME II. 



461 



ELECTRIC TESTS. 



3, 7 ; static, Reiser's, 17 ; static, 

 Salva, Dr., 17; Wheatstono and 

 Cooke's needle telegraph with 

 multiple wires and system of per- 

 mutations, 20. 



Electric tests, used in construction 

 of Malta and Alexandria telegraph 

 cables, 90 ; in sections, under 

 water, under pressure at uniform 

 temperature for conductivity and 

 insulation, 92. 



Electric thermometer, applicable at 

 a distance from place of observa- 

 tion, 158 ; applicable for geodetic 

 and meteorological purposes, 162, 

 167, 271 ; (for deep-tea measure- 

 ment t, 162, 266 ; conditions to be 

 fulfilled in, 162 ; description of, 

 163 ; dredging committee used in 

 1869, 163.) 



Electric tramway and steam tram- 

 way compared, 265. 



Electrical transmission of power, 

 economical, 188 ; suitable for 

 ploughing, reaping and thrashing, 

 260. 



Electric waves, co-existence of, in 

 conductors, discovered by Faraday, 

 32 ; rapidity of progress of, in- 

 creases with thickness of conduc- 

 tor, 30 ; (retardation of, experi- 

 ments on, 12 ; in submarine cables, 

 12 ; Thomson, W., on, 12 ; White- 

 house on, 12). 



Electricity, application of, to explo- 

 sive purposes, 127. 



Electricity, atmospheric, local dis- 

 tribution of, 128. 



Electro-induction, laws of conduc- 

 tivity applicable to, 54. 



Electro-magnetic machine, action of, 

 120 ; Clarke's improved, 199 ; 

 employment of, to illustrate dy- 

 namo - electric principle, 120 ; 

 Holmes's, produced in 1856, 199 ; 

 Pixii's, 199. 



Electro-magnetism, Oersted's dis- 



FABADAY. 



covery of in 1821, afterwards 

 extended by Schweigger, Ampere, 

 Arago, and Sturgeon, 18. 



Electro-motive force, in cables, limit 

 of, 13 ; electric wave, velocity of, 

 not influenced by, 30 ; variation 

 of, in batteries, 169. 



Elliot, O., Atlantic telegraph cable, 

 paying-out and picking-up machi- 

 nery employed in, discussion of 

 paper by, 114 119. 



Energy, transmission of, by electric 

 current, 210 ; by various methods, 

 209, 210. 



Erman. See Earth's conducting 

 power. 



Excavation, no more required for 

 telegraph poles, with than without 

 base plate, 133. 



Exciters, separate for dynamo-elec- 

 tric machine, 248. 



Exfocal light, 208. 



Expansion of metal causes increased 

 electrical resistance, 147. 



Expense of electro-horticulture de- 

 pends on cost of mechanical 

 energy, 236. 



Experimental researches on sub- 

 marine telegraph cables, 90. 



Experimental telegraph line from 

 Euston on Wheatstone's princi- 

 ple, 20. 



Experiments on electrical resistance 

 of copper, iron, silver, aluminium, 

 and platinum, 145. 



FARADAY, character of, referred to, 

 141 ; co-existence of electric waves 

 in cables, discovery of, by, 32 ; 

 decomposition of water in volta- 

 meter, law of, 169 ; electric spark 

 produced by, in 1831, by magnetic 

 induction, 198 ; (inductive action, 

 conception of, 54 ; lecture on, 40) ; 

 magneto-electric currents, discov- 

 ery of, in 1831, 18, 19. 119. 



