470 



INDEX TO VOLUME II. 



REPAIRING HEAVY CABLES, 

 ment of Varley, C., 36 ; modifica- 

 tion in, due to application of 

 magneto-electric current, 33, 34 ; 

 relative dimensions of coils in, 34 ; 

 Siemens's, 98 ; Wheatstone's, 21. 



Kepairing heavy cables, inconveni- 

 ence of, 106. 



Report of Joint Committee on con- 

 struction of submarine telegraph 

 cables, 90. 



Residuary magnetism used in 

 dynamo-electric machine, 121. 



Resistance boxes, added to Wheat- 

 stone bridge, 126 ; applicable with 

 high resistance galvanometer, 127. 



Resistance coils, protected by plati- 

 num, 164 ; of German silver used 

 in testing, 78 ; variable adjusted, 

 necessity for, 122. 



Resistance, definite units of, advan- 

 tages of, 50, 93; in dynamo-electric 

 machine for highest efficiency, 

 192 ; increased electrical due to 

 expansion of metal, 147. 



Resistance measurer, Siemens's, C.W., 

 121 ; conditions necessary in, viz., 

 zero method, linear readings, single 

 unalterable comparison resistance, 

 122 ; described by Electrical 

 Standards Committee of British 

 Association, 168 ; description of, 

 122, 123; equal to \Vheatstone 

 bridge, in accuracy, and range, 

 cheap and portable, 124 ; modifi- 

 cation of, 123 ; shifting bobbins 

 in, 123 ; simplicity of reading of, 

 124 ; sliding curve, constructed 

 for each separate instrument, 124 ; 

 uses of, for resistance thermo- 

 meters and overland wires, 124. 



Resistance measurers and galvano- 

 meters, 168. 



Resistance, mercury unit of 

 Siemens's, W., 93 ; of platinum 

 wire, increase with temperature 

 of, 125 ; of short cables, formula 

 for, 62. 



SCHWEIGGER. 



Resistance thermometer, applicable 

 where mercury thermometers could 

 not be used, 84 ; cable saved by 

 use of, 86 ; comprises battery, 

 galvanometer and thermometer 

 and variable resistance coils, 85 ; 

 description of, 85 ; method of 

 using, 85 ; resistance measurer, 

 useful for, 124 ; scientific observa- 

 tions, use of, in, 86. 



Resistance, Siemens, W., mercury 

 unit of, 50, 93 ; units of, in German 

 silver wire, 93 ; of wire, effect of 

 heat on, 125. 



Retardation, effect of leakage 

 through insulating material, 31. 



Retarding force, necessity of in 

 cable laying, 89. 



Rheostat with carbon disks under 

 pressure. 204, 212. 



Ritchie's improvement on Ampere's 

 electro-magnetic needle telegraph, 

 18. 



Ritter, and electro-magnetism, 46. 



Rolling avoided in steamship Fara- 

 day by using bilge keels, 180. 



Romagnosi, electric current, on in- 

 fluence of, on magnetic needle, 40. 



Ronalds, underground line wire re- 

 commended by, 43. 



Ruhmkorff's coil, Grove's, W. R., 

 referred to, 38. 



STE CLAIRE DEVILLE, dissociation 

 temperature of, according to, 221, 

 245. 



St. Gothard Tunnel, dynamo-electric 

 machinery for, 243, 251. 



Salva,Dr., static electric telegraph,17. 



Schilling von Canstadt's single- 

 needle telegraph in 1832, 18. 



Schiibeler, Dr., experiments on con- 

 tinuous growth, 236. 



Schweigger's electro-magnetism, ex- 

 tension of, 18 ; single-wire voltaic 

 telegraph, 18. 



