CONTENTS.
xxiii
Art.
Page
194. Application to two cases of the flow of electricity in a conducting sheet
239
195. Application to two cases of electrical induction
239
196. Capacity of a condenser consisting of a circular disk between two infinite planes
240
197. Case of a series of equidistant planes cut off by a plane at right angles to them
242
198. Case of a furrowed surface
243
199. Case of a single straight groove
243
200. Modification of the results when the groove is circular
244
201. Application to Sir W. Thomson's guard-ring
245
202. Case of two parallel plates cut off by a perpendicular plane. (Fig. XII)
246
203. Case of a grating of parallel wires. (Fig. XIII)
248
204. Case of a single electrified wire transformed into that of the grating
248
205. The grating used as a shield to protect a body from electrical influence
249
206. Method of approximation applied to the case of the grating
251
Electrostatic Instruments.
207. The frictional electrical machine
254
208. The electrophorus of Volta
255
209. Production of electrification by mechanical work.—Nicholson's Revolving Doubler
256
210. Principle of Varley's and Thomson's electrical machines
256
211. Thomson's water-dropping machine
259
212. Holtz's electrical machine
260
213. Theory of regenerators applied to electrical machines
260
214. On electrometers and electroscopes. Indicating instruments and null methods. Difference between registration and measurement
262
215. Coulomb's Torsion Balance for measuring charges
263
216. Electrometers for measuring potentials. Snow Harris's and Thomson's
266
217. Principle of the guard-ring. Thomson's Absolute Electrometer
267
218. Heterostatic method
269
219. Self-acting electrometers.—Thomson's Quadrant Electrometer
271
220. Measurement of the electric potential of a small body
274
221. Measurement of the potential at a point in the air
275
