INDEX TO VOLUME II. 



475 



TERRESTRIAL >IA(iXKTISM. 



magnetism, evidences of, { 

 88 ; laws of, determined by Gauss, 

 19. 



, apparatus for, 93; (af eablrx 

 in sections, diagrams of, 94 ; under 

 >\;iter before submersion, 76) ; for 

 faults, 1 1, 60 ; formula for, 5153 ; 



of cables, 58 ; old system, 78 ; 

 in vacuo and under pressure, 94) ; 

 of Malta and Alexandria telegraph 

 cable, 90, 158 ; for very high resist- 

 ances, 94 ; Siemens's system of , 77 ; 

 systematic, during manufacture of 

 Malta and Alexandria cable, 91 ; 

 various methods of, 91 ; with 

 Wheatstone bridge, 78. 



Thermometer, comparison coil for, 

 101 ; water bath for, 161 ; im- 

 portance of high temperature. 

 for metallurgical purposes, 159 ; 

 resistance coil, application of, 160 ; 

 described at British Association in 

 1861, 160. 



Thomson's, Sir William, marine gal- 

 vanometer, 169 ; on retardation, 

 &c., referred to, 12; inductive capa- 

 city, formula for, 55 ; lighthouse 

 characteristics, discussion of paper 

 by, 244245. 



Touch telegraph, proposed by Vors- 

 selmann de Heer, 45. 



Toulon and Algiers cable destroyed 

 by insects in eight months, 118. 



Transmission and distribution of 

 energy by electric current, 209 ; 

 expensive in first cost but cheap 

 in maintenance, 210. 



Transmission, of energy, various 

 methods of, 209, 210 ; of messages 

 in India and Turkey, difficulty of, 

 110; of power by electricity, 50 

 per cent, utilized, 188. 



Transmitters, mechanical, 114. 



Tree, strain supported by, 135. 



Trench work for underground wires, 

 10. 



Ylll.o, riY or ELECTRICITY. 



Tripod construction of posts criti- 

 cized, 133. 



Tube, of parabolic section strongest 

 section for telegraph posts, 133 ; 

 proportion of diameter and thick- 

 ness for maximum strength of, 

 133. 



Tunnels, inconvenience of travelling 

 in, owing to emission of products 

 of combustion, 251. 



Twin screw arrangement of steam- 

 ship Faraday, 139, 181. 



Twisted wire rope, Pearsall, referred 

 to, 43. 



Tyndall, J., resistance thermometer, 

 letter to, re, 84. 



Type printing instrument, House's, 

 23. 



UNDERGROUND railway, dynamo- 

 electric machines for, method of 

 applying, 252. 



Underground telegraph cable, 5 ; 

 advantages of, 9 ; failure of, 

 Highton, E., on, 41 ; Ronalds 

 recommends, 43 ; rupture of, sys- 

 tem for discovering places of, 10 ; 

 and suspended line wires, 22, 23. 



Universal galvanometer, Siemens's, 

 W., 168. 



VARLEV, acoustic telegraphs, 44 ; on 

 deep-sea cables, 44 ; dynamo-elec- 

 tric principle, work by, in connec- 

 tion with, 199 ; electric telegraph 

 instruments, 37 ; fault in French 

 Atlantic cable, reference to, 183 ; 

 telegraph arrangements of, refer- 

 ence to, 23 ; on touch telegraph, 

 44. 



Velocity of electricity uninfluenced 

 by electro-motive force, 30; Wheat- 

 stone's experiments on, 20. 



