APPENDIX.

From MS. No. 5.

ARTICLES

Prop. 1. Charge of a condenser little affected by the presence of an over-

charged body

175

Cor. 6 (Fig. 11). Two coated plates in communication little affected by

an overcharged body

185

Cor. 7. Canals may be curved as well as straight

186

Lemma. Potential of two equal particles compared with that of their

Applied to case of two parallel disks

Mutual action of large circle and trial plate in Experiment v.

Mutual action of small circles and trial plate in Experiment v.

188

189

190

192

Effect of floor and walls of the room

193

Effect of earth connexion the same as if it were infinitely long

194

THOUGHTS CONCERNING ELECTRICITY.

From MS. No. 18. (Probably an early draft of the theory.)

The fluid acts at a distance but does not itself extend to any perceptible

distance from electrified bodies

196

Proof of this, and objections to the hypothesis of electric atmospheres

On the hypothesis of electric atmospheres.

197

198

Condition of electric equilibrium between conductors in electric com-

munication

199

Illustration from the equilibrium of air

200

Definitions of positive and negative electrification, and of over and under

charge.

201

Four hypotheses

202

Cor. 1, 2. Effect of two overcharged bodies approaching each other

Fifth hypothesis, on the communication of electricity between conductor

and the surrounding air

208

From the MS. No. 7 (apparently prepared for publication).

The electricity of glass is here taken to be positive

217

First experiment. A globe within a hollow globe and in communication

with it does not become over or undercharged when the whole is

Estimation of the degree of accuracy of the result

The charge of the inner globe is less than

Hence the electric force is inversely as the square of the distance

Demonstration of this by Lemma 4 (Fig. 13)

221

222

223

224

225

226

227

228

229

230

of that of the outer globe

Limits between which the law of force must lie, n=2±

Second experiment-A piece of wood within a vessel formed of two

wooden drawers

234

235

(2) EXPERIMENTS ON THE COMPARISON OF CHARGES.

From the MS. Nos. 9 and 10 (apparently prepared for publication).

Intention of the experiments

236

Definition of the ratio of the charges of two bodies, illustrated by the

ARTICLES

The gauge electrometer

Demonstration

Form of electrometer used in the later experiments. (Fig. 30)

Estimation of error arising from unequal electrification in the two trials

Comparison of the capacities of two bodies

Why the electrification is tested by the gauge electrometer

The bodies to be tested were chosen of nearly equal capacity

Measurements of the apparatus

The insulating supports of waxed glass. (Fig. 16)

245

246

247

248

249

250

251

252

253

254

255

255

256

257

258

The electrometer threads salted

259

Third experiment. On the effect of variations in the arrangement of the

Fourth experiment. Capacities of bodies of different substances, but of

Fifth experiment. Charge of two small circles compared with that of a

Sixth experiment. Charge of two short wires compared with that of one

long one

279

Comparison with theory

280

Seventh experiment. Comparison of the capacities of several bodies

Eighth experiment. Comparison of the charge of the middle plate of

three parallel plates with that of the outer ones. (Fig. 19)

288

New apparatus for the comparison of capacities (Fig. 20).

295

Spreading of electricity on the surface of the glass. (Fig. 21)

300

Difference between different kinds of glass in this respect

301

Determination of the velocity of spreading

302

Attempt to check the spreading of electricity by means of cement.

Instantaneous spreading of electricity on the surface; electric light

Adjustment of size of coatings

Comparison of D + E + F when close together and when six inches apart

Comparison of the plates with each other.

314

315

316

317

318

Spreading=0.07 on thick plates and 0.09 on thin plates

323

ARTICLES

Charge of glass plates is many times greater than it ought to be by the

theory.

Comparison with the globe.

Consideration of the effects of external bodies on the globe and the plates
Effect of the floor and walls of the room on the charge of the globe
Experimental investigation of this effect.

Comparison of the charges of four rosin plates with those of circles 9.3,

18.5, and 36 inches diameter

Hypothesis about the relative effect of surrounding bodies on the capa-

cities of different bodies

Application of this hypothesis to the three circles and the globe.

332

333

334

335

336

337

338

339

340

341

Experiment to determine whether the air between the plates is charged

The air is not charged

Three hypotheses to explain why the charge of glass plates is rather

more than eight times what it ought to be by the theory

First hypothesis. Electricity penetrates into the glass to a certain depth

Second hypothesis. A conducting stratum within the glass. (Fig. 25).

Third hypothesis. A great number of strata alternately conducting and

non-conducting. (Fig. 26).

Conduction only normal to the surface of the plate

Reasons for preferring the third hypothesis

Another reason-analogy of Newton's fits.

Effect of different degrees of electrification on the charge of a plate

Comparison of the plate D with the circle of 36 inches diameter with two

different degrees of electrification. No apparent alteration in ca-

pacity

Correction for greater amount of spreading with the stronger degree of

electrification

357

Comparison with a very weak degree of electrification. Large cylinder

Comparison with positive and negative electrification

Accumulation at the edge is greater in plates of air than in glass plates

Charge of coated glass at different temperatures. (Fig. 28)

The edges of the coatings kept at constant temperature

Table of results at different temperatures

Glass conducts electricity better as the temperature rises

Table of the charges of glass plates

359

360

361

362

363

364

365