IN THE SERVICE OF

OF MAN:

A POPULAR AND PRACTICAL TREATISE ON THE APPLICATIONS
OF ELECTRICITY IN MODERN LIFE.

From the German of Dr. Alfred Ritter von Arbanitzky.

EDITED, WITH COPIOUS ADDitions,

BY

R. WORMELL, D.Sc., M.A.

WITH AN INTRODUCTION BY

JOHN PERRY, M.E., F.R.S.,
Professor of Mechanical Engineering and Applied Mathematics at the City and Guilds
of London Technical College, Finsbury.

Application of Ohm's Law in Coupling Elements according to Resistances

Divided Circuits and Shunts-Wheatstone's Bridge

119

121

Tables of Resistances and Conductivity

126

...

...

Units and Measurement of Resistance: Resistance Boxes-Galvanometers-Wheat-

stone's Bridge

Measurement of Electro-Motive Force: Galvanometers and Ammeters
Keys and Commutators

EFFECTS OF THE CURRENT-

Heating Effects--The Peltier Effect

128

133

140

Electro-Dynamics: Action of Galvanic Currents upon each other in Attraction and

Effects of Induction Currents-Discharges in High Vacua-Radiant Matter

Incandescent Lamps...

142

147

152

159

162

167

169

173

174

176

178

179

182

185

186

189

190

192

194

198

212

214

214

216

219