INDEX TO VOLUME II. 



465 



INK RECORDING INSTRUMENT. 



Ink recording instrument, Siemens 

 and Halske's, 98. 



Instruments, communicating and 

 receiving, 33. 



Insulated conductor, inductive capa- 

 city of, 64 ; sheathing for, 137 ; 

 Siemens's, C. W., 107. 



Insulating covering of inductor, 

 (it! ; fiiults in, testing for, in tanks, 

 93 ; flaws in, how caused, 66 ; 

 homogeneity of, 47. 



Insulating material, 99 ; (iilxorption, 

 uftvafi-r by, 100; experiments on, 

 deductions from, 100 ; pressure, 

 effect of, 100 ; salt and fresh water 

 effects, 100 ; Siemens's, W., and C. 

 W.. investigations, 100 ; table of, 

 101 ; temperature effects on, 101); 

 conductivity of, effect of tempera- 

 ture on, 49 ; improvement in gutta- 

 percha as, 61 ; specific inductive 

 capacity of, 54 ; specific resistance 

 of, formula for, 63 ; for submarine 

 cables, 91 ; tests of, 48, 49. 



Insulating media, various, compared, 

 83. 



Insulating power of gutta-percha, 

 discovered in 1848 by Siemens, 

 Werner, 11 ; of india-rubber, 67. 



Insulation, first attempts at, failure 

 of, 137 ; (ttf gutta-percha, effect 

 of pressure on, 92 ; of temperature 

 on, 104) ; Highton, E., on, 41 ; 

 improved by increased pressure, 

 by reduced temperature, 97 ; of 

 Malta and Alexandria cable, 91, 

 109 ; permanent with both gutta- 

 percha and india-rubber, 112 ; of 

 Rangoon and Singapore cable, 61 ; 

 of recent cables, 91 ; at sheathing 

 works, on board ship, and after 

 submersion, 95 ; temperature, 

 effects on, 158 ; (tests, comparison 

 of, in vacuo and under pressure, 

 94 ; with galvanometer, 51, 93 ; 

 of wires covered with gutta-percha 

 or india-rubber, and with gutta- 

 VOL. II. 



LARGE STEAM ENGINES. 



percha and india-rubber, at dif- 

 ferent temperatures, 102). 



Insulators, bell, with vulcanite stalk, 

 113 ; importance of good, 25 ; 

 Siemens and Halske's, continental 

 experience with, 25, and descrip- 

 tion of, 25. 



Iron, increase of resistance with 

 temperature, table of, 155. 



Iron sheathing, corrosion of. 113 ; 

 destruction of, by rust, 99 ; too 

 heavy for deep-sea cables, 106. 



Iron telegraph poles, 113 ; (Siemens, 

 C. W., 129 ; cost of, 131 ; 180,000 

 erected in ten years to 1873, 131 ; 

 proportion of thickness to diameter 

 of, 130 ; suitable for tropical 

 countries, 132 ; uniform strength 

 of, 137). See Telegraph poles. 



Izarn, G., " Manuel du Galvanisme " 

 by, 39. 



JABLOSCHKOFP'S electric candle, 

 description of, 191 ; -requires alter- 

 nating currents, 191, 200. 



Jacobi, india-rubber used by, in 

 1840, for insulating purposes, 67, 

 99, 138. 



Jekyll, Lieut., on telegraph poles, 

 discussion of paper by, 132 137. 



Jockey for regulating strain on 

 cable, 140. 



KIEL, cable submerged in bay of, by 

 Siemens, Werner, 12, 22, 26. 



Kohlrausch, British Association unit 

 determined by, 217. 



LADD'S and Brush's application of 

 Wheatstone's suggestion regarding 

 dynamo-electric current, 217. 



La Heve, electric and oil light at, 

 207. 



Large steam engines more economical 

 than small, 189 



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