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Title A Treatise on Electricity and Magnetism
Author James Clerk Maxwell
Year 1873
Publisher Clarendon Press
Location Oxford
Source djvu
Progress Proofread—All pages of the work proper are proofread, but not all are validated
Transclusion Fully transcluded
Volumes Vol. 1Vol. 2
Pages (key to Page Status)
- - - - - - i ii iii iv v vi vii viii ix x xi xii xiii xiv xv xvi xvii xviii xix xx xxi xxii xxiii xxiv xxv xxvi xxvii xxviii xxix xxx xxxi xxxii xxxiii xxxiv 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 - - 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460

CONTENTS.

On the Measurement of Quantities.
Art.
Page
001. The expression of a quantity consists of two factors, the numerical value, and the name of the concrete unit
001
002. Dimensions of derived units
001
003–5. The three fundamental units—Length, Time and Mass
2, 3
006. Derived units
005
007. Physical continuity and discontinuity
006
008. Discontinuity of a function of more than one variable
007
009. Periodic and multiple functions
008
10. Relation of physical quantities to directions in space
008
11. Meaning of the words Scalar and Vector
009
12. Division of physical vectors into two classes, Forces and Fluxes
10
13. Relation between corresponding vectors of the two classes
11
14. Line-integration appropriate to forces, surface-integration to fluxes
12
15. Longitudinal and rotational vectors
12
16. Line-integrals and potentials
13
17. Hamilton's expression for the relation between a force and its potential
15
18. Cyclic regions and geometry of position
16
19. The potential in an acyclic region is single valued
17
20. System of values of the potential in a cyclic region
18
21. Surface-integrals
19
22. Surfaces, tubes, and lines of flow
21
23. Right-handed and left-handed relations in space
24
24. Transformation of a line-integral into a surface-integral
25
25. Effect of Hamilton's operation on a vector function
27
26. Nature of the operation
29
PART I.
Electrostatics.
Description of Phenomena.
Art.
Page
27. Electrification by friction. Electrification is of two kinds, to which the names of Vitreous and Resinous, or Positive and Negative, have been given
30
28. Electrification by induction
31
29. Electrification by conduction. Conductors and insulators
32
30. In electrification by friction the quantity of the positive electrification is equal to that of the negative electrification
33
31. To charge a vessel with a quantity of electricity equal and opposite to that of an excited body
33
32. To discharge a conductor completely into a metallic vessel
34
33. Test of electrification by gold-leaf electroscope
34
34. Electrification, considered as a measurable quantity, may be called Electricity
35
35. Electricity may be treated as a physical quantity
36
36. Theory of Two fluids
37
37. Theory of One fluid
39
38. Measurement of the force between electrified bodies
40
39. Relation between this force and the quantities of electricity
41
40. Variation of the force with the distance
42
41, 42. Definition of the electrostatic unit of electricity.—Its dimensions
42
43. Proof of the law of electric force
43
44. Electric field
44
45. Electric potential
45
46. Equipotential surfaces. Example of their use in reasoning about electricity
45
47. Lines of force
47
48. Electric tension
47
49. Electromotive force
47
50. Capacity of a conductor
48
51. Properties of bodies.—Resistance
48
52. Specific Inductive capacity of a dielectric
50
53. 'Absorption' of electricity
50
54. Impossibility of an absolute charge
51
55. Disruptive discharge.—Glow
52
56. Brush
54
57. Spark
55
58. Electrical phenomena of Tourmaline
56
59. Plan of the treatise, and sketch of its results
57
60. Electric polarization and displacement
59
61. The motion of electricity analogous to that of an incompressible fluid
62
62. Peculiarities of the theory of this treatise
62
Elementary Mathematical Theory of Electricity.
63. Definition of electricity as a mathematical quantity
66
64. Volume-density, surface-density, and line-density
67
65. Definition of the electrostatic unit of electricity
68
66. Law of force between electrified bodies
69
67. Resultant force between two bodies
69
68. Resultant force at a point
69
69. Line-integral of electric force; electromotive force
71
70. Electric potential
72
71. Resultant force in terms of the potential
72
72. The potential of all points of a conductor is the same
73
73. Potential due to an electrified system
74
74. Proof of the law of the inverse square
74
75. Surface-integral of electric induction
77
76. Introduction through a closed surface due to a single centre of force
77
77. Poisson's extension of Laplace's equation
79
78. Conditions to be fulfilled at an electrified surface
80
79. Resultant force on an electrified surface
82
80. The electrification of a conductor is entirely on the surface
83
81. A distribution of electricity on lines or points is physically impossible
84
82. Lines of electric induction
84
83. Specific inductive capacity
86
Systems of Conductors.
Art.
Page
84. On the superposition of electrified systems
88
85. Energy of an electrified system
88
86. General theory of a system of conductors. Coefficients of potential
89
87. Coefficients of induction. Capacity of a conductor. Dimensions of these coefficients
90
88. Reciprocal property of the coefficients
91
89. A theorem due to Green
92
90. Relative magnitude of the coefficients of potential
92
91. And of induction
93
92. The resultant mechanical force on a conductor expressed in terms of the charges of the different conductors of the system and the variation of the coefficients of potential
94
93. The same in terms of the potentials, and the variation of the coefficients of induction
94
94. Comparison of electrified systems
96
General Theorems.
95. Two opposite methods of treating electrical questions
98
96. Characteristics of the potential function
99
97. Conditions under which the volume-integral
vanishes
100
98. Thomson's theorem of the unique minimum of
103
99. Application of the theorem to the determination of the distribution of electricity
107
100. Green's theorem and its physical interpretation
108
101. Green's functions
113
102. Method of finding limiting values of electrical coefficients
115
Mechanical Action between Electrified Bodies.
Art.
Page
103. Comparison of the force between different electrified systems
119
104. Mechanical action on an element of an electrified surface
121
105. Comparison between theories of direct action and theories of stress
122
106. The kind of stress required to account for the phenomenon
123
107. The hypothesis of stress considered as a step in electrical science
126
108. The hypothesis of stress shewn to account for the equilibrium of the medium and for the forces acting between electrified bodies
128
109. Statements of Faraday relative to the longitudinal tension and lateral pressure of the lines of force
131
110. Objections to stress in a fluid considered
131
111. Statement of the theory of electric polarization
132
Points and Lines of Equilibrium.
112. Conditions of a point of equilibrium
135
113. Number of points of equilibrium
136
114. At a point or line of equilibrium there is a conical point or a line of self-intersection of the equipotential surface
137
115. Angles at which an equipotential surface intersects itself
138
116. The equilibrium of an electrified body cannot be stable
139
Forms of Equipotential Surfaces and Lines of Flow.
117. Practical importance of a knowledge of these forms in simple cases
142
118. Two electrified points, ratio . (Fig. I)
143
119. Two electrified points, ratio . (Fig. II)
144
120. An electrified point in a uniform field of force. (Fig. III)
145
121. Three electrified points. Two spherical equipotential surfaces. (Fig. IV)
145
122. Faraday's use of the conception of lines of force
146
123. Method employed in drawing the diagrams
147
Simple Cases of Electrification.
Art.
Page
124. Two parallel planes
150
125. Two concentric spherical surfaces
152
126. Two coaxal cylindric surfaces
154
127. Longitudinal force on a cylinder, the ends of which are surrounded by cylinders at different potentials
155
Spherical Harmonics.
128. Singular points at which the potential becomes infinite
157
129. Singular points of different orders defined by their axes
158
130. Expression for the potential due to a singular point referred to its axes
160
131. This expression is perfectly definite and represents the most general type of the harmonic of degrees
162
132. The zonal, tesseral, and sectorial types
163
133. Solid harmonics of positive degree. Their relation to those of negative degree
165
134. Application to the theory of electrified spherical surfaces
166
135. The external action of an electrified spherical surface compared with that of an imaginary singular point at its centre
167
136. Proof that if and are two surface harmonics of different degrees, the surface-integral , the integration being extended over the spherical surface
169
137. Value of where and are surface harmonics of the same degree but of different types
169
138. On conjugate harmonics
170
139. If is the zonal harmonic and any other type of the same degree
where is the value of at the pole of
171
140. Development of a function in terms of spherical surface harmonics
172
141. Surface-integral of the square of a symmetrical harmonic
173
142. Different methods of treating spherical harmonics
174
143. On the diagrams of spherical harmonics. (Figs. V, VI, VII, VIII, IX)
175
144. If the potential is constant throughout any finite portion of space it is so throughout the whole region continuous with it within which Laplace's equation is satisfied
176
145. To analyse a spherical harmonic into a system of conjugate harmonics by means of a finite number of measurements at selected points of the sphere
177
146. Application to spherical and nearly spherical conductors
178
Confocal Surfaces of the Second Degree.
147. The lines of intersection of two systems and their intercepts by the third system
181
148. The characteristic equation of in terms of ellipsoidal coordinates
182
149. Expression of , , in terms of elliptic functions
183
150. Particular solutions of electrical distribution on the confocal surfaces and their limiting forms
184
151. Continuous transformation into a figure of revolution about the axis of
187
152. Transformation into a figure of revolution about the axis of
188
153. Transformation into a system of cones and spheres
189
154. Confocal paraboloids
189
Theory of Electric Images.
155. Thomson's method of electric images
191
156. When two points are oppositely and unequally electrified, the surface for which the potential is zero is a sphere
192
157. Electric images
193
158. Distribution of electricity on the surface of the sphere
195
159. Image of any given distribution of electricity
196
160. Resultant force between an electrified point and sphere
197
161. Images in an infinite plane conducting surface
198
162. Electric inversion
199
163. Geometrical theorems about inversion
201
164. Application of the method to the problem of Art. 158
202
165. Finite systems of successive images
203
166. Case of two spherical surfaces intersecting at an angle
204
167. Enumeration of the cases in which the number of images is finite
206
168. Case of two spheres intersecting orthogonally
207
169. Case of three spheres intersecting orthogonally
210
170. Case of four spheres intersecting orthogonally
211
171. Infinite series of images. Case of two concentric spheres
212
172. Any two spheres not intersecting each other
213
173. Calculation of the coefficients of capacity and induction
216
174. Calculation of the charges of the spheres, and of the force between them
217
175. Distribution of electricity on two spheres in contact. Proof sphere
219
176. Thomson's investigation of an electrified spherical bowl
221
177. Distribution on an ellipsoid, and on a circular disk at potential
221
178. Induction on an uninsulated disk or bowl by an electrified point in the continuation of the plane or spherical surface
222
179. The rest of the sphere supposed uniformly electrified
223
180. The bowl maintained at potential and uninfluenced
223
181. Induction on the bowl due to a point placed anywhere
224
Conjugate Functions in Two Dimensions.
182. Cases in which the quantities are functions of and only
226
183. Conjugate functions
227
184. Conjugate functions may be added or subtracted
228
185. Conjugate functions of conjugate functions are themselves conjugate
229
186. Transformation of Poisson's equation
231
187. Additional theorems on conjugate functions
232
188. Inversion in two dimensions
232
189. Electric images in two dimensions
233
190. Neumann's transformation of this case
234
191. Distribution of electricity near the edge of a conductor formed by two plane surfaces
236
192. Ellipses and hyperbolas. (Fig. X)
237
193. Transformation of this case. (Fig. XI)
238
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
222. Measurement of the potential of a conductor without touching it
276
223. Measurement of the superficial density of electrification. The proof plane
277
224. A hemisphere used as a test
278
225. A circular disk
279
226. On electric accumulators. The Leyden jar
281
227. Accumulators of measurable capacity
282
228. The guard-ring accumulator
283
229. Comparison of the capacities of accumulators
285
PART II.
Electrokinematics.
The Electric Current.
230. Current produced when conductors are discharged
288
231. Transference of electrification
288
232. Description of the voltaic battery
289
233. Electromotive force
290
234. Production of a steady current
290
235. Properties of the current
291
236. Electrolytic action
291
237. Explanation of terms connected with electrolysis
292
238. Different modes of passage of the current
292
239. Magnetic action of the current
293
240. The Galvanometer
294
Conduction And Resistance.
241. Ohm's Law
295
242. Generation of heat by the current. Joule's Law
296
243. Analogy between the conduction of electricity and that of heat
297
244. Differences between the two classes of phenomena
297
245. Farady's doctrine of the impossibility of an absolute charge
298
Electromotive force between bodies in contact.
246. Volta's law of the contact force between different metals at the same temperature
299
247. Effects of electrolytes
300
248. Thomson's voltaic current in which gravity performs the part of chemical action
300
249. Peltier's phenomenon. Deduction of the thermoelectric electromotive force at a junction
300
250. Seebeck's discovery of thermoelectric currents
302
251. Magnus's law of a circuit of one metal
302
252. Cumming's discovery of thermoelectric inversions
304
253. Thomson's deductions from these facts, and discovery of the reversible thermal effects of electric currents in copper and in iron
304
254. Tait's law of the electromotive force of a thermoelectric pair
305
Electrolysis.
255. Faraday's law of electrochemical equivalents
307
256. Clausius's theory of molecular agitation
309
257. Electrolytic polarization
309
258. Test of an electrolyte by polarization
310
259. Difficulties in the theory of electrolysis
310
260. Molecular charges
311
261. Secondary actions observed in the electrodes
313
262. Conversation of energy in electrolysis
315
263. Measurement of chemical affinity as an electromotive force
316
Electrolytic polarization.
264. Difficulties of applying Ohm's law to electrolytes
318
265. Ohm's law nevertheless applicable
318
266. The effect of polarization distinguished from that of resistance
318
267. Polarization due to the presence of the ions at the electrodes. The ions not in a free state
319
268. Relation between the electromotive force of polarization and the states of the ions at the electrodes
320
269. Dissipation of the ions and loss of polarization
321
270. Limit of polarization
321
271. Ritter's secondary pile compared with the Leyden jar
322
272. Constant voltaic elements.—Daniell's cell
325
Mathematical Theory of the Distribution of Electric Currents.
273. Linear conductors
329
274. Ohm's Law
329
275. Linear conductors in series
329
276. Linear conductors in multiple arc
330
277. Resistance of conductors of uniform section
331
278. Dimensions of the quantities involved in Ohm's law
332
279. Specific resistance and conductivity in electromagnetic measure
333
280. Linear systems of conductors in general
333
281. Reciprocal property of any two conductors of the system
335
282. Conjugate conductors
336
283. Heat generated in the system
336
284. The heat is a minimum when the current is distributed according to Ohm's law
337
Conduction in Three Dimensions.
285. Notation
338
286. Composition and resolution of electric currents
338
287. Determination of the quantity which flows through any surface
339
288. Equation of a surface of flow
340
289. Relation between any three systems of surfaces of flow
340
290. Tubes of flow
340
291. Expression for the components of the flow in terms of surfaces of flow
341
292. Simplification of this expression by a proper choice of parameters
341
293. Unit tubes of flow used as a complete method of determining the current
341
294. Current-sheets and current-functions
342
295. Equation of 'continuity'
342
296. Quantity of electricity which flows through a given surface
344
Resistance and Conductivity in Three Dimensions.
Art.
Page
297. Equations of resistance
345
298. Equations of conduction
346
299. Rate of generation of heat
346
300. Conditions of stability
347
301. Equation of continuity in a homogeneous medium
348
302. Solution of the equation
348
303. Theory of the coefficient . It probably does not exist
349
304. Generalized form of Thomson's theorem
350
305. Proof without symbols
351
306. Strutt's method applied to a wire of variable section.—Lower limit of the value of the resistance
353
307. Higher limit
356
308. Lower limit for the correction for the ends of the wire
358
309. Higher limit
358
Conduction Through Heterogeneous Media.
310. Surface-conditions
360
311. Spherical surface
362
312. Spherical shell
363
313. Spherical shell placed in a field of uniform flow
364
314. Medium in which small spheres are uniformly disseminated
365
315. Images in a plane surface
366
316. Method of inversion not applicable in three dimensions
367
317. Case of conduction through a stratum bounded by parallel planes
367
318. Infinite series of images. Application to magnetic induction
368
319. On stratified conductors. Coefficients of conductivity of a conductor consisting of alternate strata of two different substances
369
320. If neither of the substances has the rotatory property denoted by the compound conductor is free from it
370
321. If the substances are isotropic the direction of greatest resistance is normal to the strata
371
322. Medium containing parallelepipeds of another medium
371
323. The rotatory property cannot be introduced by means of conducting channels
372
324. Construction of an artificial solid having given coefficients of longitudinal and transverse conductivity
373
Conduction in Dielectrics.
Art.
Page
325. In a strictly homogeneous medium there can be no internal charge
374
326. Theory of a condenser in which the dielectric is not a perfect insulator
375
327. No residual charge due to simple conduction
376
328. Theory of a composite accumulator
376
329. Residual charge and electrical absorption
378
330. Total discharge
380
331. Comparison with the conduction of heat
381
332. Theory of telegraph cables and comparison of the equations with those of the conduction of heat
381
333. Opinion of Ohm on this subject
384
334. Mechanical illustration of the properties of a dielectric
385
Measurement of the Electric Resistance of Conductors.
335. Advantage of using material standards of resistance in electrical measurements
388
336. Different standards which have been used and different systems which have been proposed
388
337. The electromagnetic system of units
389
338. Weber's unit, and the British Association unit or Ohm
389
339. Professed value of the Ohm  metres per second
389
340. Reproduction of standards
390
341. Forms of resistance coils
391
342. Coils of great resistance
392
343. Arrangement of coils in series
392
344. Arrangement in multiple arc
393
345. On the comparison of resistances. (1) Ohm's method
394
346. (2) By the differential galvanometer
394
347. (3) By Wheatstone's Bridge
398
348. Estimation of limits of error in the determination
399
349. Best arrangement of the conductors to be compared
400
350. On the use of Wheatstone's Bridge
402
351. Thomson's method for small resistances
404
352. Matthiessen and Hockin's method for small resistances
406
353. Comparison of great resistances by the electrometer
408
354. By accumulation in a condenser
409
355. Direct electrostatic method
409
356. Thomson's method for the resistance of a galvanometer
410
357. Mance's method of determining the resistance of a battery
411
358. Comparison of electromotive forces
413
Electric Resistance of Substances.
359. Metals, electrolytes, and dielectrics
415
360. Resistance of metals
416
361. Resistance of mercury
417
362. Table of resistance of metals
418
363. Resistance of electrolytes
419
364. Experiments of Paalzow
419
365. Experiments of Kohlrausch and Nippoldt
420
366. Resistance of dielectrics
421
367. Gutta-percha
423
368. Glass
423
369. Gases
424
370. Experiments of Wiedemann and Rühlmann
425
PLATES. (not in original TOC)