University of California. 
 
LIBRARY 
 
 TY OF 
 
A GENERAL INDEX 
 
 TO THE CONTENTS OF 
 
 FOURTEEN POPULAR TREATISES 
 
 NATURAL PHILOSOPHY, 
 
 FOR THE USE OF 
 
 STUDENTS, TEACHERS, AND ARTIZANS. 
 
 BY A 
 
 MASSACHUSETTS TEACHER. 
 
 1872 : 
 IVISON, BLAKEMAN, TAYLOR & CO. 
 
 NEW YORK AND CHICAGO. 
 
Entered, according to Act of Congress, in the year 1872, by 
 
 IVISON, BLAKEMAN, TAYLOR &, CO., 
 in the office of the Librarian of Congress, Washington. 
 
PKEFACE. 
 
 Books of reference of all kinds are specially needful in this country to 
 supplement the teachings of the common school, the workshop and the 
 printing house. In a community where the average intelligence is excep- 
 tionally high, where almost everyone has a more or less distinct " gen- 
 eral idea " of a great variety of subjects, though few persons are really 
 learned in any one department of knowledge, Encyclopaedias and Dic- 
 tionaries of the Arts and Sciences find many readers. 
 
 It has occurred to the author that a new and useful kind of reference 
 book may be made by collating the Tables of Contents and Indices of a 
 considerable number of standard treatises on any given subject, to form a 
 compendious General Index, in which the student may learn at a glance 
 where to find information upon any special point. 
 
 A tool or implement of instruction of this sort, which can be afforded 
 at a price low enough to bring it within the reach of all, would be spe- 
 cially valuable in these days when school libraries and public libraries, 
 which contain the books referred to, are springing up on every hand. 
 
 The idea in question is applicable of course to almost any subject, but to 
 none more so than to that of Natural Philosophy. In seeking to reduce his 
 conception to practice, the author has therefore attempted an Index of 
 Physical Titles, in the belief that the subject at least will commend his 
 effort to American artificers and teachers'. 
 
 It is to be remarked that the apparent meagreness of many of the refer- 
 ences in the following general index is due for the most part to the differ- 
 ent methods of treating their subject, which have been followed by the 
 authors of the several books consulted. One set of details is treated of in 
 one book, and another set in another. There is far less of repetition and 
 of similarity among the various works than would naturally be supposed. 
 Herein will be found a strong argument in favor of the idea of which this 
 little book is the exponent. 
 
LIB HA RY 
 
 UNIVKKSITV OF 
 
 (',ALH<'OUX1.-V. ) 
 
 LIST OF ABBREVIATIONS USED IN THIS INDEX. 
 
 f THE NEW AMERICAN CYCLOPEDIA: A Popular Dictionary of General 
 A. -5 Knowledge. Edited by Kipley & Dana. New York: Appleton & Co., 
 
 ( 1859-1863. Vols. i-xvi. 
 
 A SUPPLEMENT to the American Cyclopaedia for the years '61 to '69. 
 . o j PRINCIPLES OF PHYSICS AND METEOROLOGY. By J. Muller. Philadelphia: 
 
 1 Lea & Blanchard,' 1848. 
 Q^ j ELEMENTS OF CHEMICAL PHYSICS. By J. P. Cooke, Jr. Boston: Little & 
 
 1 Brown, 1860. 
 
 v D. \ ELEMENTS OF CHEMISTRY, THEORETICAL AND PRACTICAL. By W. A. Mil- 
 ( ler. London: 1857. 3 Vols. 
 (FIRST PRINCIPLES OF PHYSICS, OR NATURAL PHILOSOPHY; designed for the 
 
 E. -N use of Schools and Colleges. By Benjamin Silliman, Jr. Philadelphia: 
 ( Peck & Bliss, 1859. 
 
 i j ( PRINCIPLES OF PHYSICS. By Benjamin Silliman, Jr. Second Edition, re- 
 | vised and rewritten. Philadelphia: T. Bliss & Co., 1865. 
 (ELEMENTS OF NATURAL PHILOSOPHY; being an experimental introduction to 
 
 F. J the study of the Physical Sciences. By Golding Bird, M.D. 3d Edition. 
 ( Philadelphia: Lea & Blanchard, 1848. 
 
 f WELLS' s NATURAL PHILOSOPHY; for the use of Schools, Academies and Pri- 
 Gr- < vate Students. With 375 engravings. By David A. Wells, A.M. New 
 ( York: Ivison, Blakeman, Taylor & Co. 
 A CYCLOPAEDIA OF THE PHYSICAL SCIENCES. By J. P. Nichol. London 
 
 and Glasgow: R. Griffin & Co., 1857. 
 
 j S INTRODUCTORY COURSE OF NATURAL PHILOSOPHY. Edited from Ganot's 
 I Popular Physics. By W. G. Peck. New York: Barnes & Burr, 1860. 
 /-ELEMENTARY TREATISE ON PHYSICS, EXPERIMENTAL AND APPLIED. For 
 j j the use of Colleges and Schools. Translated and edited from Ganot's Ele- 
 ") ments de Physique. By E. Atkinson, Ph.D. Fourth Edition, revised and 
 enlarged. New York: Wm. Wood & Co., 1869. 
 
 5 THE CORRELATION AND CONSERVATION OF FORCES; A Series of Expositions. 
 By Profs. Grove, Helmholtz, Mayer, Faraday, Liebig and Youmans. New 
 York: Appletoiis, 1865. 
 
 fHEAT CONSIDERED AS A MODE OF MOTION; being a course of twelve lec- 
 * < tures delivered at the Royal Institution of Great Britain in the season of 1862. 
 
 ( By John Tyndall, F. R. S. -New York: Appletons, 1864. 
 
 jy/j ( SOUND. A course of eight lectures delivered at the Royal Institution of Great 
 ( Britain. By John Tyndall, LL.D. London: Longmans, Green & Co., 1867. 
 f ELEMENTS OF NATURAL PHILOSOPHY ; designed for Academies and High 
 N - I Schools. By Elias Loomis, LL.D. New York: Harpers, 1860. 
 
 ( 
 ( 
 
LIBRARY 
 
 UNIVERSITY OF 
 
 CALIFORNIA. 
 
 INDEX. 
 
 Abel's electrical fuse, J, 674. 
 Aberration, see Light. 
 
 chromatic, see Light. 
 
 of glass covers, E, 510; E, 818. 
 
 of lenses, E, 454. 
 
 of mirrors, E, 437. 
 Absolute Strength, see Tenacity. 
 Absolute weight, see Weight. 
 
 zero of temperature, see Temperature. 
 Absorber of heat, see Heat. 
 Absorption, A, i, 42; I, 68; J, 107; see 
 Imbibition. 
 
 in animals, J, 109 ; E, 308. 
 
 of gases, see Gases. 
 
 of heat, see Heat. 
 
 heat produced by, see Heat. 
 
 in plants, J, 108 ; E, 308. 
 
 power of, J, 337. 
 
 metre (Bunsen's), C, 402, 409. 
 Acceleration, A. i, 60 ; C, 23 ; H, 4. 
 
 of a force, J, 12, 52. 
 
 of gravity, C, 65. 
 Accent in music, A, i, 64. 
 Accidental images, J, 525. 
 Accord, A, i, 64. 
 Accords, I, 171. 
 Accordion, A, i, 64. 
 Achromatism, E, 778 ; E, 466 ; F, 
 
 305; H, 6; J. 479. 
 
 Achromatopsy, see Color Blindness. 
 Acidometer, J, 95. 
 Aclinic lines, F, 159. 
 Acoustic figures, F, 147; G, 189. 
 
 Acoustic shadow, E, 430 ; E, 350 ; 
 
 F, 140. 
 Acoustics, A, i, 75; B, 207; E, 416; 
 
 E, 335; F, 138; G, 188; H, 6. 
 defined, I, 156; N, 176. 
 experiments of Schaffgotsch, L, 292. 
 Actinic intensity of daylight, A, '67, 70. 
 line, J, 590. 
 
 ray, A, I, 79, and xm, 290; I, 314. 
 Actinism, A, i, 79; G, pp. 343, 344; H, 
 
 11; J, 347, 470. 
 Actinometer, A, i, 80; A, n, 325; C, 
 
 49; H, 11. 
 Action and reaction, A, xi, 325; C, 49; 
 
 E, 27; F, 74; G, 66; J, 23. 
 Action of glass on mercury, N, 141. 
 Actual energy defined, L, 151. 
 Adhesion, A, i, 124; B, 77; C, 342; D 
 I, 33, 56; E, 34; F, 58; G, pp 
 25,29; H, 13; 1,65; J, 62. 
 between gases, C, 412. 
 
 solids, C, 342; E, 104; G, 
 
 29; N, 138. 
 
 distinguished from cohesion, E, 147. 
 of gases to liquids, C, 391; D, I, 77. 
 
 solids, C, 379, 383; D, I, 
 
 78; F, 62. 
 
 general character of. D, i, 57. 
 of india rubber, C, 343; D,i, 57. 
 influence of on affinity, D, n, 1096. 
 
 surface on, D, I, 63, and 
 
 ii. 1096. 
 of liquids, C, 383; D, I, 67; G, 29. 
 
Adhesion of liquids to solids, B, 108; 
 
 C, 344; G, 29; N, 138. 
 phenomena of classified, C, 342. 
 of solids, C, 342; E, 104; G, 29; N, 
 
 138. 
 
 of water to glass, N, 140. 
 JEolipilr, see Eolipile. 
 Aeration of Water, D, i, 77. 
 Aerial meteors, ,T, 834. 
 phenomenn, E, 957. 
 waves, E, 332. 
 Aerodynamics, A, i. 150. 
 Aerolites, A, i, 150, and xi, 412; G, pp. 
 
 288,289; H, 14. 
 velocity of, L, 23. 
 Aerometer, A, i, 152. 
 Aeronautics, A, i, 152; H, 15. 
 Aerostation, A, i, 152. 
 Aether, A, i, 159; see Ether. 
 Aethrioscope, A, i, 160; L, 407. 
 Affinity, chemical, see Chemical affinity. 
 Agonic lines, F, 158; .1, 585. 
 Aim, philosophy of taking, G, 295. 
 Air [compare Atmosphere and Gases], 
 
 A, i, 252, and II, 306; E, 312. 
 a bad conductor of heat, B, 649. 
 buoyancy of, E, 258. 
 capacity of for heat, A, n, 309. 
 
 for moisture, E, 1064; 
 G, 268. 
 
 cause of nocturnal cooling of, L, 414. 
 chilly in spring, why, G, 246. 
 composition of, A, u, 307 ; G, 163. 
 
 at different places, D, n, 453. 
 compressed, chilled by expansion, L, 
 
 27. 
 compressed, phenomena attending its 
 
 escape from orifices, F, 133. 
 compressibility of, A, u, 309; G, 164. 
 compression of, containing bisulphide 
 
 of carbon, L, 43, 71. 
 compression of, machine for at Schem- 
 
 nitz, L, 46. 
 
 cooling effect of, L, 253. 
 damp, B, 594. 
 density of at increasing altitudes 
 
 [table], D, i, 51; G, 165. 
 downward pressure of, D, i, 45. 
 dry, B, 594. 
 
 absorption of heat by, L, 341. 
 dynamic radiation of, L, 383. 
 
 Air, effect of stoppage of motion of, L, 44. 
 elasticity of, A, u, 309; F, 122, 128; 
 
 G, 165; N, 154. 
 
 elasticity and density of, G, 166; M, 23. 
 emits heat when compressed, A, I, 252. 
 escaping from containing vessels, F, 
 
 132. 
 
 expanded by heat, L, 79. 
 expansion of by heat, C, 540; L, 78. 
 expansion of by heat under constant 
 
 pressure, L, 80, volume, L, 82. 
 expansive force of, E, 316 ; 'i, 106. 
 flow of, to and from tropics, L, 183. 
 fresh, amount required by a man, G, 
 
 261. 
 
 from bellows, heated, L, 28. 
 heat disengaged by compression of, A, 
 
 in, 338; D, I, 213. 
 heat absorbed during rarefaction of, 
 
 D, i, 214. 
 
 heated air ascends, G, 261; experi- 
 ments proving this, L, 182. 
 
 heating by, J, 405; how heated, G, 
 218. 
 
 humid, table of absorption by at dif- 
 ferent tensions, L, 399, 409. 
 
 humidity of, E, 1064. 
 
 impenetrability of, A, u, 309 ; E, 314 ; 
 
 E, 259. 
 
 inertia of, E, 315; E, 260; G, 164; 
 
 N, 153. 
 
 materiality of, N, 153. 
 the medium of sound, N, 161. 
 moisture in, and its effects, G,^268; 
 
 I, 245. 
 necessary to combustion and life, N, 
 
 161 and 162. 
 not warmed by passage of heat 
 
 through, L, 319. 
 passage of sound through, G, 191 ; L, 
 
 261. 
 pressure of, A, n, 308; G, 174. 
 
 amount of, G, 174; N, 164. 
 measured, N, 159. 
 shown, N, 158. 
 
 pure (perfectly) difficulties in obtain- 
 ing, L, 391. 
 resistance of, A, xi, 322, 323 ; N, 92, 
 
 161. 
 Saturated with moisture, absorption of 
 
 heat by, L, 396, 410 f 413. 
 
Air has no sensible power of radiating 
 
 heat; deduced from the velocity of 
 
 sound, M, 34. 
 in sounding pipes, its state, E, 379 ; 
 
 M, 185 and 214. 
 temperature of at increasing altitudes 
 
 (table), D, i, 214. 
 thermal effect of moving, L, 43. 
 is the type of gases, E, 313. 
 vapor in, A, n, 308. 
 varnishing of by vapors, L, 385. 
 weight of, A, ir, 308; xm, 411; E, 
 
 317; G, 168; I, 107; N, 157. 
 weight of a cubic inch, D, n, 453; 
 
 F, 122. 
 
 weight in, loss of, correction for, J, 317. 
 Air in music, A, I, 252. 
 balloons, J, 142. 
 bladder, A, I, 253. 
 cells, A, I, 254. 
 chamber, J, 161. 
 engine, A, n, 309; E, 708; H, 15; 
 
 N, 213. 
 gun, A, i, 254; H, 20. 
 
 action of the, K, 219, 220. 
 pipe, A, i, 254. 
 pump, A, i, 255; B, 132; E, 364; 
 
 E, 287; F, 126; H, 20; I, 128; 
 
 G, pp. 176, 177; J, 146; N, 154. 
 pump, Bianchi's, J, 150. 
 
 condensing, J, 154. 
 
 construction, N, 154. 
 
 degree of exhaustion, C, 327. 
 
 experiments with, I, 132. 
 
 formula for, C, 327, 328. 
 
 gauge, J, 148. 
 
 measure of the rarefaction pro- 
 duced by, I, 132. 
 
 piston of, J, 162. 
 
 receiver of, J, 146. 
 
 Sprengel's, J, 153. 
 
 single barrel, D, r, 38. 
 
 with two barrels, D, I, 38. 
 
 uses of the, J, 155. 
 
 valve, N, 155. 
 
 with valves, C, 329. 
 
 without valves, C, 325. 
 thermometer, J, 258. 
 vessels, A, 1, 255. 
 Ajutage, F, 132; J, 165. 
 
 Alcarazzas, A, vit, 502, 345 ; A, ix, 
 
 434; J, 290. 
 
 Alcoholic value of wines, J, 294 . 
 Alcoholometer, J, 96 ; see Hydrometer. 
 
 centesimal, J, 97. 
 Alembics, E, 642; I, 241. 
 Allotropic modifications of carbon, D, 
 
 n, 489. 
 modifications of phosphorus, D, n, 593. 
 
 sulphur, D, n, 560. 
 Allotropism, A, v, 44; A, ix, 636; D, i, 
 
 112. 
 Alloys, A, i, 382; J, 264. 
 
 expansion of. in solidifying, C, 553. 
 general properties of, D, n, 673. 
 inferior to pure metals as electrical 
 
 conductors, D, I, 362. 
 melting points of, C, 550. 
 Alphabet, Morse's telegraphic, N, 342. 
 Altitude, A, I, 422; N, 168. 
 
 and Azimuth instrument, H, 23. 
 Altitudes measured by barometer, G, 
 173 ; N, 168 ; measured by boil- 
 ing water, G, 242 : N, 169. 
 Amalgams, A, i, 436; D, n, 674; E, 
 
 934; E, 834; J, 635. 
 Kienmayers, J, 636. 
 for electrical machine, A, vn, 61 ; D r 
 
 I, 278; F, 183; use of, F, 184. 
 Amalgamation, A, '66, 15; E, 971. 
 of plates, E, 868. 
 of zinc, J, 694. 
 
 voltaic use of, A, vii, 67 ; D, 
 
 1,316; F, 311. 
 Amorphism, E, 90. 
 Ampere, discoveries of, E, 908. 
 theory of, E, 908; J, 743. 
 's stand, J, 730. 
 Amplitude of sound vibrations, M, 9 
 
 and 11. 
 
 of vibrations, J, 934. 
 Analysis, A, i, 510. 
 
 of central forces, E, 54. 
 of colors, E, 458. 
 of light, A, '61, 657; E, 456. 
 by absorption, E, 458. 
 by prisms, E, 456. 
 of wheel work, E, 117. 
 Anchor ice, A, ix, 433. 
 Ancients, philosophic aims of the, K, 13- 
 
Ancients, their methods of explaining 
 
 phenomena, K, 103. 
 Anelectrics, F, 170; J, 608 and 629. 
 Anemograph, A, xvi, 475. 
 Anemometer, A, I, 560 ; A, xvi, 475 ; 
 E, 1062; E, 960; G, 282; H,25; 
 J, 834. 
 
 Anemoscope, A, i, 562 ; E, 959. 
 A 111; I of aperture. A, n, 473 ; E, 820. 
 
 critical, J, 446. 
 
 of deviation, B, 69 ; J, 449, 450. 
 
 defined, G, 71 ; optic, E, 782. 
 
 polarizing, J, 551; see Polarizing An- 
 gle. 
 
 of reflection and refraction, B, 260, 270. 
 
 of repose, J, 23. 
 
 see visual angle. 
 
 Animal body, constancy of the temper- 
 ature of, L, 229. 
 
 body, capacity of bearing heat, L, 
 229, 230. 
 
 electricity, E, 943 ; see Electricity, 
 peculiar current of, J, 829. 
 
 force, see Force. 
 
 heat, see Heat. 
 
 levers, F, 102. 
 
 mechanics, A, 1, 599. 
 
 strength, E, 130. 
 Animalculae, N, 17. 
 Anions, A, vn, 65. 
 
 and cathions, D, 11, 1114. 
 Annealing, A, i, 615; C, 207, 211; E, 
 178; G,27; J, 66. 
 
 of glass, C, 212. 
 
 of wire, A, xvi, 493. 
 Anode, B, 437 ; E. 882 ; H, 27. 
 Anone, A, iv, 575. 
 Anthelia, H, 28. 
 Anthotype, F, 394. 
 A plan at ic foci, E, 509. 
 
 lens, see Lens. 
 
 Apparatus Atwood's, B, 152; E, 72; 
 E, 157 ; H, 53 ; J, 51 ; N, 25 and 
 85. 
 
 Bianchi's and Thilorier's, E, 690. 
 
 Bohnenberger's, E, 55. 
 
 distilling, E, 687. 
 
 illustrating barometer, E, 264. 
 
 Melloni's, E. 642. 
 
 Morin's, B, 72. 
 Apparent magnitude of an object, J, 484. 
 
 Aqueducts, construction of, A, i, 729 ; 
 
 G, 134. 
 
 Aqueous Humor, J, 514. 
 phenomena, E, 972. 
 Arago's experiment, E, 1020; E, 
 
 912; J, 133. 
 polariscope, E, 557. 
 Arbor Dianae, J, 725 ; Saturni, J, 725. 
 Arc of vibration, J, 33. 
 Arch, A, n,20; G, 120. 
 Arches, cast iron, N, 79. 
 examples, N, 78. . 
 figure of, N, 75. 
 how built, G, 120; N, 75. 
 pointed, N, 77. 
 theory of, G, 120; N, 74; wooden, N, 
 
 77. 
 
 Archery, A, n, 26. 
 Archimedean screw, see Screw. 
 Archimedes, principle of. B, 90, 95; 
 C, 235, 237; E, 257; F, 112; G, 
 44; H, 27; I, 90, J, 86; N, 130. 
 principle of, applied to gases, J, 141. 
 problem of, F, 96. 
 theorem of, E, 205. 
 
 demonstrated, E, 206. 
 Are, E, 18. 
 Area, unit of, J, 10. 
 Areometer, see Hydrometer. 
 Armatures, see Miignets. 
 Armillary Sphere, H, 39. 
 Artesian Wells, see Wells. 
 Asbestos, cause of bad conduction of 
 
 heat, L, 247. 
 
 incombustibility of, A, n, 192. 
 Ascent of liquids in tubes, E, 239. 
 Aspirator, C, 325, 392. 
 Astatic multiplier j com Galvanom . 
 
 needle 
 
 eter, E, 882 ; E, 787 ; F, 242 ; 
 G, 430; J, 592; N, 328. 
 described, with preparation of, L, 33. 
 Athermancy, A, vi, 449; D, i, 204; J, 
 
 348. 
 
 of olefiant gas, L, 349, et seq. 
 Atlantic cable, see Telegraph. 
 
 Ocean, Europe the condenser of, L, 194. 
 Atmometer, A, n, 306. 
 
 Leslie's. A, n, 306. 
 
 Atmosphere, A. n, 306; A. '65, 100; 
 B, 116; E, 256; H, 45. 
 
Atmosphere, absorption of solar heat 
 
 by, L, 319, 433. 
 action of aqueous vapor in, on radiant 
 
 heat, L, 391. 
 amount of aqueous vapor in, B, 589; 
 
 1,248; L, 390. 
 buoyancy of, C, 268 ; I, 149. 
 composition of, D, n, 452 ; F, 121 ; G, 
 
 163; H, 45; 1,108; J, 114. 
 compound nature of, D, n, 438. 
 contains free electricity, E, 861; 
 
 N, 311. 
 
 crushing force of, J, 114. 
 decrease of temperature in the upper 
 
 regions of the, B, 576. 
 density of the, N, 167. 
 
 at different altitudes, 
 
 D, I, 50 ; H, 48. 
 description of the, I, 106. 
 determination of amount, J, 115, 117. 
 dew point of, see Dew point, 
 diminution of its pressure lowers boil- 
 ing point, L, 129, et seq. 
 distribution of vapor in, B, 589. 
 effect of an diffusion of light, G, 302. 
 effects of expansion of, C, 540. 
 elasticity of, D. I, 36, et seq. 
 electricity of, B, 616; E, 860; F, 
 
 204; J, 851. 
 V source of, N, 313. 
 
 a source of heat, E, 
 
 747. 
 
 varies and why, F, 205. 
 finite extent of, F, 122. 
 height of the, I, 121 ; N, 167. 
 how heated, G, pp. 218, 226. 
 influence of vapor upon its power of 
 
 conducting heat, A, ix, 17. 
 limits, probable of, C, 307; D, I, 52; 
 
 E, 318; F, 122; G,173; K, 136. 
 power of accumulating heat, A, xi, 415. 
 pressure of the, B, 119, 124; C, 266, 
 
 279; D,l, 46; E, 319; E, 257; 
 
 F, 122, 125, 127, 128; G, 168; H, 
 45; I, 108; J, 113; K, 319. 
 
 pressure of the, effects produced by, 
 
 G, pp. 174, 175. ' 
 
 pressure of the, formula for, C, 279. 
 pressure of the, how sustained, G, 179. 
 pressure of the, on human body, E, 
 321; 1,122; J, 156 and 117. 
 
 Atmosphere, pressure of 
 
 of, E, 320; E, 261; I, M|f/l - 
 pressure of the, transmitted in* klf 
 
 directions, I, 121. 
 varies constantly, A, 
 
 n, 657. 
 
 refraction of, E, 538 ; G, 314. 
 relative humidity of, C, 640; I, 248. 
 retains the dark heat which radiates 
 
 from the earth, A, xi, 415, 416. 
 temperature of, decreases with eleva- 
 tion, E, 602. 
 transmits heat of high intensity, A, 
 
 XI, 415, 416. 
 
 use of aqueous vapor in, L, 405. 
 vapor in, A, VI, 432; vn, 345; B, 593; 
 
 B, 595; F, 373. 
 waves of. see Waves, 
 weight of, F, 122. 
 Atmospheric air, see Air. 
 engine, see Air Engine, 
 inkstand, see Pneumatic do. 
 railways, A, n, 311. 
 telegraph, see Pneumatic dispatch. 
 Atomic constitution, influence of on the 
 
 absorption of heat, L, 364. 
 forces, power of, L, 93. 
 heat, J, 374; heats, D, in, 784. 
 heats of elements (table), D, in, 785. 
 
 compounds (table), D, in, 787. 
 motion how propagated, L, 76. 
 oscillations increased by heat, L, 74. 
 theory, A, 11, 313; v, 39; C, 110; D, 
 
 1, 14 and HI, 767. 
 theory, objections to, K, 164. 
 volume, Kopp's law of, D, HI, 774. 
 volumes of carbonates, sulphates, ni- 
 trates and chlorides (table), D, m, 
 770, 771, 772. 
 
 volumes of compound gases, D, in, 760. 
 liquids (table of), 
 
 D, in, 776. 
 
 volume of compound solids, D, in, 768. 
 elementary gases (table), D, 
 
 in, 759. 
 elementary solids (table), D, 
 
 in, 764. 
 
 influence of isomorphism and 
 dimorphism upon, D, 
 m, 766. 
 temperature, D, in, 767. 
 
 : 
 
6 
 
 Atomic volumes of oxides (table), D, 
 
 lit, 769, 770. 
 salts in solution (ta- 
 ble), D, in, 774. 
 
 weights, see Equivalents, chemical. 
 Atoms, A, II, 315; B, 30; D, I, 5; m, 
 758; E, 10; E, 20; F, 49; G, 
 13; J, 1. 
 absorb and emit same rays of heat, 
 
 L, 426. 
 
 collection of carbon and oxygen, L, 59. 
 enormous attractions of, L, 163. 
 essential properties of, F, 50. 
 form of, E, 11; F, 50, 51. 
 question of existence of, K, 347. 
 all simple atoms have the same amount 
 
 of dynamic energy, L, 156. 
 size of, C, 110; E, 12; F, 50, 51; G, 
 
 13. 
 
 Ultimate, N, 18. 
 weight of, E, 15. 
 when separated, heat consumed, L, 
 
 154. 
 Attraction, A, n, 831; F, 51; G, pp. 
 
 17, 22, 30. 
 
 adhesive, see Adhesion, 
 and repulsion, relation between, K, 
 
 39. 
 
 and repulsion of floating bodies, F, 62. 
 light bodies, E, 831. 
 capillary, see Capillary Attraction, 
 chemical, see Chemical Affinity. 
 cohesive, see Cohesion, 
 of earth, see Gravity, 
 electric, see Electrical Attraction, 
 forms of, D, i, 5; F, 57; G, 24. 
 laws of, F, 57 ; molecular, ,T, 60. 
 seeming, of bodies by aerial currents, 
 
 F, 133. 
 
 of solids and liquids, B, 145. 
 universal, see Gravity, 
 varieties of, D, I, 5. 
 
 Attractions at sensible distances, F, 64. 
 Atwood's machine, B, 152; E, 157; 
 E, 72, H, 53; J, 61; N, 25 and 85. 
 Audibility, limit of, D, i, 210, note. 
 Auditory nerve, B, 261; see Ear and 
 
 Hearing. 
 
 organs of man, E, 393. 
 August's Psychrometer or Hygrometer, 
 B, 593; E, 973. 
 
 Aurora, A, n, 362; A, '62, 177; '65, 
 100; D, I, 314; E, 994; E, 
 1084; F, 209; G, 396; H, 54; I, 
 430; J, 586, 861. 
 distribution of, E, 997. 
 effect on telegraphs, E, 999. 
 ' has no influence on weather, G, 291. 
 height of, A, n, 363; E, 996. 
 magnetic disturbance, A, n, 364; E, 
 
 998; D, I, 315. 
 not local, G, 397. 
 peculiarities of, G, 397. 
 remarkable, E, 995. 
 Auroral current, reversal of polarity in, 
 
 E, 1000. 
 
 Auscultation, A, n, 367. 
 Austral poles, J, 683. 
 Automaton, A, n, 406. 
 Avalanche, A, n, 411. 
 Avoirdupois, G, 34; J, 11. 
 Axe, A, ii, 422. 
 Axes of crystals; see Crystals; Axes 
 
 secondary, B, 281. 
 Axis, A, II, 423; G, 82. 
 of moments, A, xi, 320. 
 of oscillation, J, 56. 
 in peritrochio, A, H, 423. 
 Axle, see Wheel and Axle. 
 Axles of railway cars, why liable to 
 
 break, G, 28. 
 Azure, A, n, 435. 
 
 Babbage's experiment on friction, E, 
 
 140. 
 Bab i net's formula, C, 305. 
 
 stopcock, J, 150. 
 
 Background, E, 786; E, 476. 
 Bagpipe, A, n, 486. 
 Balance, A, n, 608; B, 67: C, 100; F, 
 
 94; H, 57; I, 50; J, 46; N, 46. 
 accuracy of a, C, 102; N, 47. 
 beam of, J, 47. 
 bent lever, N, 48. 
 centre of gravity of, how adjusted, 
 
 C, 101. 
 
 compensation, J, 247. 
 described, G, 97; N, 46. 
 essential parts of the, D, i, 26. 
 false, N, 47. 
 
 hydrostatic, B, 95 ; C, 248 ; E, 257 ; 
 H, 6; 1,91. 
 
Balance knife edges, J, 47. 
 - method of testing, I, 53. 
 
 weighing correctly with a 
 
 -false, G, 98; 1,53. 
 physical and chemical, J, 49. 
 regarded as a lever, C, 101. 
 
 pendulum, C, 102. 
 requisites for a good, I, 52. 
 sensibility of, B, 70 ; C, 102, 105. 
 spring, E, 37 ; N, 49. 
 
 indicates absolute weight, C, 
 
 94, 189. 
 
 theory of, F, 93. 
 torsion, A, n, 510; C, 193; E, 918; 
 
 F, 172; G, 382; J, 64, 594, 615. 
 wheels, compensation, E, 535. 
 Ball on jet, N, 152. 
 Ballast, use of in vessels, G, 139. 
 Ballistic curve, E, 232 ; E, 145. 
 
 pendulum, E, 104; H, 61. 
 Balloons, A, i, 152; n, 540; C, 270; 
 E, 340; E, 273; G, 186; H, 61; 
 I, 150; J, 142. 
 ascents, Glaisher's, J, 143. 
 ascent of, F, 67 ; G, 43. 
 ascents remarkable, I, 155. 
 ascensional force of, C, 271. 
 
 formula for, C, 272. 
 construction of, E, 341 ; J, 143. 
 filling of, E, 341; 1,151. 
 fire, D, I, 193 ; L, 80. 
 management of, I, 151 ; J, 143. 
 Ballooning, A, '62, 184. 
 Balls, cannon, velocity of, G, 76. 
 Barker's Mill, A, xv, 643; E, 217; G, 
 
 157; J, 167; N, 126. 
 
 Barometer, A, n, 653; A, '62, 189; '65, 
 112; B, 121; C, 275, 284; D, I, 44; 
 
 E, 320, et seq.; E, 261, et seq.; 
 
 F, 123; H, 62; I, 113; J, 117. 
 aneroid, A, n, 658; C, 285; E, 333; 
 
 E, 164; G, 172; H, 64; J, 138. 
 apparatus illustrating principle 'of, E, 
 
 324; E, 264. 
 boiling point, A, n, 658". 
 Bourdon's, E, 334. 
 Bunten's, E, 328; J, 121. 
 cistern, E, 326; E, 266; I, 114; J, 
 
 118. 
 capillary depression of mercury in, D, 
 
 I, 62. 
 
 Barometer, Cavendish's double, B, 400. 
 construction of, A, n, 655; B, 121; E, 
 
 322; E, 263; G, 171. 
 corrections, F, 124; J, 123; errors 
 
 of, E, 269. 
 
 diurnal variation of, see variations of. 
 fixed, J, 127. 
 fluctuations of (causes), A, n, 657; I, 
 
 118; N, 165; see variations of. 
 Fortin's, C, 282; E, 327; E, 266; 
 
 J, 119. 
 
 for use at sea, A, n, 657, 658. 
 Gay-Lussac's, E, 328; E, 267; J, 
 
 121. 
 
 gauge, B, 136 ; G, 259. 
 at different heights, E, 265. 
 height of, B, 121; J, 118. 
 heights measured by, A, m, 659; B, 
 
 130; C, 304; D, I, 51; E, 272; 
 
 G, 173; J, 127; N, 168. 
 horary variations of, F, 124. 
 how to fill, see construction of. 
 index, I, 118. 
 indications of, affected by heat and 
 
 capillarity, see corrections, 
 invention of the, G, pp. 169, 171. 
 mean diurnal height, A, n, 657; F, 
 
 124; I, 117. 
 mercurial, A, n, 653, et seq.; C, 284; 
 
 F, 123; N, 162. 
 deteriorates with age, A, n, 
 
 656. 
 
 metallic, E, 263. 
 oscillations of, B, 579; C, 286; see 
 
 fluctuations and variations of. 
 Pascal's experiments on the, E, 323; 
 
 I,- 113. 
 
 precautions with, J, 122. 
 properties of a good, I, 116. 
 Kegnault's, C, 280. 
 self-registering, A, n, 656. 
 syphon, A, 11, 655; B, 122; H, 65; I, 
 
 116; J, 121. 
 theory of, C, 278. . 
 thermo, J, 285. 
 uses of, C, 285, 287, 304. 
 variations of, A, n, 657; G, 124; J, 
 124, 125; see fluc- 
 tuations of. 
 
 height in, E, 270 ; J, 
 124. 
 
Barometer, variations of, and relation 
 to the weather, A, n, 656 ; E, 271 ; 
 G, 173; J, 125; N, 165. 
 water, A, n, 653, 656; D, I, 42; F, 
 
 123; G, 172; N, 166. 
 as a weather indicator, see above, va- 
 riations, 
 wheel, E, 329: G, 171; J, 126; N, 
 
 164. 
 Barometric column, height at different 
 
 elevations, E, 325. 
 formula, J, 128. 
 
 Laplace's, J, 129. 
 gauge, B, 136 ; G, 259. 
 measurements, A, n, 659. 
 observations, causes of error in, E, 
 
 330. 
 
 corrected for capillarity, 
 C, 284, 355; E, 331; 
 F, 124 ; see Barome- 
 ter corrections, 
 corrected for tempera- 
 ture, C, 284, 511; E, 
 332; E, 599; J, 
 251. 
 
 formula for, C, 611, 512. 
 Baroscope, A, n, 622 ; J, 141. 
 Bars, musical sound produced by heated, 
 
 M, 53. 
 
 Battering ram, A, n, 740. 
 Battery* Bragation's, A, vii, 75. 
 Becquerel's, F, 236. 
 
 simple voltaic circuits, 
 
 D, I, 334. 
 nitric acid and potash, D, 
 
 I, 335; D, il, 1117. 
 
 Bunsen's, A, vn, 67; B, 419; D, I, 
 342; E, 978; F, 217; J, 690; N, 
 317. 
 
 Callan's, J, 691. 
 
 calorific effects of, F, 224 ; I, 440. 
 chemical effects of, I, 442. 
 constant (of Daniell), see Daniell (be- 
 low). 
 
 Cruikshank's, A, vn, 66. 
 Daniell's, A, vn, 67; B, 417; D, I, 
 339; E, 976; F, 216, 283; G, 
 407; J, 688. 
 
 decline in power, causes of, D, i, 338. 
 effects of, F, 223, 225 ; I, 438. 
 
 Battery? electrical, A, vn, 63; D, i, 292, 
 
 302; E, 947; F, 196; G. 384; H, 
 
 67; I, 412; J, 656. 
 floating (of De La Rive), F, 247; J, 
 
 738. 
 
 of frogs, F, 268. 
 
 gain of power by absorption of hy- 
 drogen, F, 217. 
 galvanic, A, Vii, 66; E, 972, 980; E, 
 
 869, 881 ; F, 219, et seq. ; G, 401 ; 
 
 H, 68; J, 684, 696. 
 galvanic, a misnomer, E, 864. 
 gas, D, I, 336; F, 226; J. 724. 
 gravity, J, 693. 
 Grove's, A, vn, 67; B, 417; D, I, 341; 
 
 E, 977; F, 217, 221, 226; G, 406; 
 
 J,689; N, 316. 
 Hare's, A, vn, 66. 
 heat from, F, 224; I, 440. 
 illuminating effects of, F, 223; G, 410; 
 
 I, 441. 
 
 Leyden, charged by coil, J, 797. 
 local, J, 759. 
 
 measurement of charge, J, 659. 
 Menotti's, J, 693. 
 
 most effective combination, D, i, 355. 
 Nobili's, J, 812. 
 physiological effects of, I, 439. 
 of pigeons (Matteuci's), F, 270. 
 poles of, F, 225; G, 402; N, 319. 
 postal battery, J, 761. 
 refrigerating effects of, F, 225. 
 Smee's, A, vii, 67; D, I, 342; E, 
 
 974; E, 871; F, 214; G, 406; J 
 
 691; N, 317. 
 sulphate of copper, E, 975; G, 406. 
 
 mercury, J, 692. 
 tension of, J, 694. 
 theory of, N, 318. 
 thermo electric, A, xv, 426; B, 479; 
 
 D, I, 407; E, 1044, 521; G, 417; 
 
 J, 813, 341 ; Becquerel's, E, 
 
 941; F, 261 j H, 727; J, 813; L, 
 
 14, 30; N, 337; see Thermo, 
 transfer of matter during discharge 
 
 of, F, 223. 
 trough, A, vii, 66; E, 973; E, 
 
 70; G, 405. 
 
 voltaic, see Battery, galvanic. 
 Volta's cup, N, 315. 
 
Battery, Walker's, J, 692. 
 
 water, D, i, 377. 
 
 of wells excites, F, 225, 228. 
 
 Wilkinson's, N, 316. 
 
 Wollaston's, A, vn, 66; B, 427. 
 Beam, A, in, 5. 
 
 or bar when strongest, G, 115. 
 
 of balance, J, 47. 
 
 flexure of, E, 162. 
 
 lateral strength of, E, 172. 
 
 rectangular strength of, G, 116. 
 
 why liable to break when bent in the 
 
 middle, G, 119. 
 Beats, D, i, 142; J, 197. 
 
 action on flame, M, 264. 
 
 dissonance due to, M, 298, 301. 
 
 in musical notes, D, I, 142. 
 
 optical illustration of, M, 266. 
 
 theory of, M, 263. 
 Beating, E, 459 ; E, 376. 
 Becquerel's constant circuit, B, 416, 
 
 425. 
 Bell, A, in, 91. 
 
 analysis of vibrations, M, 150, 158. 
 
 diving, see Diving bell. 
 
 struck by a hammer, motion not lost, 
 L, 41. 
 
 of a trumpet, J, 185. 
 
 in vacuo, experiments on, M, 6. 
 
 vibrations of, N, 195. 
 
 Bellows, A, in, 106, 381 { B, 201; E, 
 355 ;E, 281; H, 72; I, 181; J, 
 188, 205. 
 
 continuous blast, E, 356, 
 
 hydrostatic, A, m, 109 ; G, 129. 
 Belts in machinery, A, m, 109. 
 
 friction of, A, in, 109. 
 
 motion communicated by, G, 101. 
 Berthollet's experiment, J, 139. 
 Bertsch's machine, J, 642. 
 Beveled wheel, N, 53. 
 Bianchi's air pump, J, 150. 
 Billiards, principles of the game of, 
 
 G, 72. 
 Binary theory of salts, D, n, 704. 
 
 objection to, D, 
 
 n, 707. 
 
 Blii4n-l% ? J, 588. 
 Binocular vision, see Vision. 
 Black's experiments, J, 377. 
 
 Black dresses, optical effect of, G, 333. 
 Bladder, swimming, I, 95; J, 89. 
 Blanket, utility of nap of the, G, 219. 
 Blasting by electricity, E, 937. 
 
 gunpowder, A, in, 337. 
 Bleaching, A, in, 341. 
 Block and tackle, J, 24. 
 Blood of animals, N, 16. 
 
 globules, J, 5. 
 
 heat of, why so constant in all 
 
 cljrnates, L, 230. 
 Blotting paper, why it absorbs ink, G, 
 
 147- 
 
 Blow or shock, A, xv, 60; when most 
 
 severe, G, 69. 
 Blower, furnace, use of the, E, 357; 
 
 G, 262. 
 Blowing machines, A, in, 106, 381, 
 
 383; B, 199. 
 Blowpipe, A, in, 383. 
 
 flame, oxidizing, D, 11, 641. 
 reducing, D, 11, 640. 
 mouth, D, n, 639. 
 
 oxyhydrogen, A, in, 384; D, n, 471. 
 heat of, I), 11, 449. 
 Henning's jet, D, II, 
 
 471, 635. 
 
 Blueing of metals, see Tempering. 
 Bode's law, H, 74. 
 Bodies, classification of, I, 12. 
 collision of inelastic, G, 69. 
 general properties of, B, 73; I, 13. 
 fornj. of, I, 13; how dependent on 
 heat, G, 228; how changed by 
 centrifugal force, G, 83. 
 Ojpagnitude of, I, 13. 
 jHrhen : called hot, G, 206. 
 $oat in air, G, 185. 
 heavy and light, G, 33. 
 luminous, G, pp. 294, 301. 
 appear white, G, 301. 
 solid, liquid or gaseous, G, 24. 
 Body defined, C, 3; E, 1; G, 11; I, 
 
 11; N, 13. 
 density of a, I, 12. 
 laws of falling, see Falling Bodies, 
 mass of a, I, 12. 
 
 size of, how affects its strength, G, 115. 
 when rolls and when slides down a 
 slope, G, 51. 
 
 2 
 
10 
 
 Body when stands most firmly, G, 50. 
 will have no weight at centre of the 
 
 earth, G, 33. 
 Bohnenberger's machine, E, 180; E, 
 
 55. 
 
 electroscope, B, 404. 
 Boilers, steam, E, 685; G, 256; J, 383. 
 annular, see Fire Engine, 
 effect of incrustations, L, 
 
 248. 
 explosions, A, xv, 60; L, 
 
 127, 178. 
 
 [flue], A, xv, 59; G, 258. 
 Gold's heater, E, 733. 
 locomotive, C, 618; G, 
 
 258. 
 
 steam chest of, A, xv, 59. 
 tubular, A, xv, 59. 
 wagon, A, xv, 59. 
 
 Boiling, A, vn, 346, and xv, 44; D i, 
 222; E, 676; F, 371; G, 241; H, 
 207; I, 229; J, 269. 
 by cooling, J, 283, 
 explosive, L, 126. 
 laws of, J, 280. 
 
 point, A, in, 434, vn, 346; E, 569: 
 G, 241; H, 207; J, 281; L, 
 128; N, 210. 
 
 application of, in arts, E, 678. 
 causes that modify, A, xv, 428; 
 D, 1,222 ;E, 676 ; G, 242 ; I, 
 231. 
 
 determination of, C, 569. 
 influence of adhesion on, D, I, 
 
 223 ; E, 629. 
 dissolved substances 
 D, L, 224, 225 [Ta- 
 ble]; E,630; J, 
 281. 
 of nature of vessel 
 
 on, J, 283. 
 of pressure on, C, 
 566, 577; D, I, 
 225; E, 631; G, 
 242; L, 121, 130; 
 J, 28. 
 of liquids under diminished 
 
 pressure, D, I, 225. 
 lowered as we ascend a moun- 
 tain, i.e., as pressure of air is 
 removed, A, n, 308, 658 ; L, 130. 
 
 Boiling, measurement of heights by, C 
 667; E, 634;- E, 679; J, 
 284; G, 242. 
 
 ratio of pressure to, F, 373. 
 on summits of Mts. Blanc, Rosa, 
 etc., E, 634; E, App., 18; 
 L, 120. 
 
 true definition of, L, 129. 
 of water, C, 565; G, 241; N, 
 
 210. 
 
 effect of salts on, C, 568. 
 vessel, C, 568. 
 raised by removing the gases 
 
 dissolved, L, 126. 
 under different pressures [table] 
 D, i, 227 ; E, Appendix, Ta- 
 bles 16 and 19. 
 why selected as a standard of 
 
 temperature, L, 106. 
 points of the compound ethers, D, in, 
 
 780, 782. 
 Kopp's law of, A, v, 43; D, in, 
 
 778. 
 of liquids, E, Appendix, 17; D, 
 
 in, 782. 
 of metameric compounds, D, ill, 
 
 782. 
 organic liquids (table), D, in, 
 
 779, 782. 
 
 table of, C, 666; D, i, 222, and 
 in, 779, etseq.; E, 628; E, 
 appendix tables, 16-19. 
 in a thermometer, J, 381. 
 resistance to, L, 129. 
 Bologna vial, A, in, 460. 
 
 stone, A, in, 460. 
 Bones of animals, why cylindrical, G, 
 
 118. 
 
 Boomerang, A, in, 510. 
 Bore, A, in, 522. 
 Boreal pole, J, 583. 
 Boscovitch's theory, H, 74; J, 303. 
 Boutigny's experiments, see Sphe- 
 roidal state. 
 
 Brachystochrome, E, 76. 
 Brake, A, in, 633. 
 Bramah's lock, see Lock; press, see 
 
 Press. 
 
 Brazing, A, in, 652. 
 Breaking weight, J, 6Q. 
 Breath figures, see Roric figures. 
 
11 
 
 Breath, why visible in winter, G, 274. 
 Breathing, mechanical operation of, G, 
 
 181. 
 Breezes, land and sea, G, 284; J, 836; 
 
 L, 87. 
 Bridge, Wheatstone's, J, 824; Brit- 
 
 tania, E, 172; G, pp. 118, 119. 
 British yard, J, 10, 94. 
 Brittleness, C, 205; D, i, 54, and n, 
 666, 670; E,. 177; F, 42, 55; G, 
 27. 
 
 Bronchi, B, 246. 
 Brush, discharge, J, 664. 
 Bubble, A, iv, 32. 
 
 soap, why it rises in the air, G, 
 
 43. 
 Buckets of wheels, G, 156 ; see water 
 
 wheels. 
 
 Bude light, A, iv, 72. 
 Building materials, A, '62, 201. 
 
 how selected, G, 
 
 122. 
 stones, Brard's process for testing, D, 
 
 n, 804. 
 on what depends the strength 
 
 of, G, 119. 
 
 how warmed arid ventilated, see Heat- 
 ing and Ventilation. 
 Bull's eye, J, 488. 
 Buoyancy of air, E, 258. 
 centre of, A, ix, 414. 
 of liquids, E, 205; J, 73. 
 what is, G, 138. 
 Burette, A, iv, 109. 
 Burner, Bunsen's, J, 474. 
 
 fish tail and bat's wing, experiments 
 
 with, M, 232. 
 Burning glass, A, iv, 134; E, 593; 
 
 G, 209; H, 82; I, 306. 
 mirrors, A, iv, 134; J, 334. 
 Burnishing, A, iv, 134. 
 
 Calliope, A, iv, 270. 
 
 Calms, the region of, L, 188. 
 
 Calorescence, J, 348. 
 
 Caloric, A, iv, 274; ix, 2-3; G, 206; J, 
 
 365 ; compare Heat, 
 proved not to exist by Davy, L, 107. 
 engine, see Air Engine. 
 Calorific effects of current electricitj', 
 J, 708. 
 
 Calorific effects of discharge, J, 667. 
 
 RuhmkorfTs coil, J, 
 
 795. 
 equivalents, D, in, 789, 803. 
 
 indirect method of es- 
 timating, D, in, 797. 
 power of a body, Rumford's estima- 
 tion of, L, 163. 
 
 Calorimeter, A, iv, 274 ; H, 87. 
 Black's, J, 367. 
 Favre & Sibermann's, J, 381. 
 Hare's, B, 415. 
 ice, J, 367. 
 
 Lavoisier's, E, 597 ; J, 367. 
 mercurial, D, in, 799. 
 water, of Favre, D, in, 792. 
 Calorimetry, E, 594; E, 650; J, 
 
 365. 
 Calorimotor, A, iv, 275. 
 
 Hare's, A, vii, 66; B, 415; E, 973. 
 Calotype, B, 345; D, n, 1136; F, 392; 
 
 H, 87. 
 
 Camel, for lifting ships, A, iv, 302. 
 Camera Aeolia, see Trompe. 
 
 lucida, A, iv, 307; E, 518; F, 398; 
 
 H, 89; J, 503; N, 251. 
 Wollaston's, F, 825. 
 obscura, A, iv, 307; B, 315,344; E, 
 824; E, 517; F, 346; 
 G, 347; H, 89; I, 342; N, 
 250. 
 
 Amici's, J, 500 and 510. 
 erect image, 1, 346. 
 photographic, F, 388. 
 portable for artists, G, 360; 
 
 I, 347. 
 
 prismatic, F, 347. 
 Canals, how constructed, A, iv, 343; G, 
 
 137. 
 
 Cannon, A, iv, 363; G, pp. 28, 77. 
 Capillarity, A, iv, 403; C, 346, 363; 
 D, I, 59; E, 232; F, 57, 59; G, 
 pp. 25, 142; H, 92; J, 98; N, 138; 
 compare Adhesion, 
 amount of pressure by, C, 351, 349. 
 applications of, I, 67. 
 attraction and repulsion of, D. I, 61; 
 
 F, 61; J, 100. 
 causes of, E, 288. 
 difficulty of theory of, J, 102. 
 in double plates, F, 60; N, 141. 
 
12 
 
 Capillarity, formulae for, C, 357, 358. 
 illustrations of, C, 353, 362; G, 143. 
 influenced by curve of surface, E, 
 290; E,236; J, 101. 
 temperature, C, 360. 
 laws of, C, 355, 357; E, 287, 291; 
 
 E, 237; F, 60. 
 of liquids (table), D, I, 61. 
 opposed to evaporation, F, 61. 
 phenomena of, C, 346, 354; E, 286, 
 
 297; E, 233; J, 98, 103. 
 in single plates, F, 69. 
 a source of heat, E, 741. 
 Capillary attraction, see Capillarity. 
 depression of mercury, D, I, (51; F, 61. 
 forces, I, 66. 
 plates, C, 357, 359. 
 tubes, F, 69; J, 99. 
 
 ascent of liquids in, B, 108; C, 
 354, 358, 360 J E; 293; 
 G, 143. 
 
 and depression in, J, 99. 
 depression of mercury in, E, 
 
 292; N, 142. 
 
 flow of liquids through, t), i, 74. 
 Capstan, A, iv, 410; E, 202; E, 
 
 116; G, 100; N, 60. 
 Carre's method of freezing, J, 2S9; 
 Cartesian devil or diver, E, 259; E, 
 
 206; F, 112; J, 88. 
 Cartier's scale, B, 106. 
 Cascade, charging by, J, 657. 
 Case hardening, A, iv, 511; D, il, 889. 
 Casting of metals, A, iv, 532. 
 Castor and Pollux, F, 209. 
 Catadioptric illumination, A, x, 521. 
 Catalysis, A, iv, 650; D, it, 1099; K, 
 
 6, 169. 
 
 Liebig's theory of, D, n, 1100. 
 Mercer's theory of, D, n, il02. * 
 Catalytic actions, Brodie's experiments, 
 
 D, n, 1104. 
 Catenary, N, 76. 
 Cathetometer, C, 185, 281 { J, 63. 
 Cathode, A, iv, 575; vn, 65; B, 437; 
 
 E, 882. 
 Cations, A, vii, 65. 
 
 Catoptrics, A, iv, 680; xii, 536; E, 
 
 415; F, 276; G, 312; H, 94. 
 Catoptric illumination, A, x, 520. 
 telescope, J, 495, see Telescope. 
 
 Causation, Grove on r K, 16. 
 
 secondary, K, 18. 
 Cause and effect, K, 251. 
 
 simultaneity of, K, 17. 
 nature of, K, 402. 
 Caustics, A, iv, 597; B, 268; E, 763; 
 
 E, 437; H, 100; J, 441. 
 by reflection, F, 284. 
 
 refraction, F, 294; H, 169. 
 Cavendish's experiment, N, 89. 
 Celestial dynamics (Mayer's essay on), 
 
 K, 259; L, 85, 440. 
 Cellars, why cool in summer and warm 
 
 in winter, G, 220. 
 Cements, A, iv, 639. 
 
 principle of their use, C, 343; D, I, . 
 CHtitnetre, E, 18; J, 96. 
 Central forces, A, iv, 652; E, 175; 
 
 H, 100. 
 
 analysis of motion pro- 
 duced by, E, 176; 
 E, 54. 
 he-at, see 1 Heat. 
 Centre of buoyancy, see Buoyancy. 
 
 gratity, A, iv, 652, xi, 320; B, 
 61; C, 60; E, 142; 
 E, 60, 62; F, 68; 
 G, 45; H, 101; 1,43; 
 J, 43; N, 36. 
 consequences of, F, 69. 
 defined, N, 36. 
 density of body not 
 
 uniform, E, 149. 
 determination of, E, 
 
 143; F, 68; G, 48. 
 different positions of, 
 
 N, 89. 
 of irregular solids, A, 
 
 XI, 321; G, 48. 
 positions of, C, 61; N, 
 
 39. 
 
 properties of, N, 37. 
 of regular figures, E, 
 
 144; E,64. 
 a straight line, N, 37. 
 three bodies, N, 36. 
 a triangle, N, 37. 
 without the body, E, 
 
 65. 
 
 in what three ways 
 supported, G, 47. 
 
18 
 
 Centre of gravity, when at rest, G, 46. 
 .of oscillation, C, 70; E, 165; E, 
 
 83; F, 91; H, 104. 
 parallel forces, F, 93; J, 22. 
 percussions, F, 91. 
 pressure (fluid), C, 220, 240; E, 
 
 197; F, 110. 
 
 Centrifugal force, A, iv, 653, and xi, 
 323; B, 162; C, 77, 
 79;E,52;F,72; 
 H, 100; 1,30. 
 computed, N, 94. 
 at equator, C, 82. 
 demonstration, E, 53. 
 described, N, 93. 
 effect on a yielding 
 mass, E, 179, G, 83. 
 formula fdr, C, 80--*83v 
 illustrations of, E, 
 
 177; I, 32; N, 98. 
 measure of, C, 80. 
 modifying gravity, C, 
 
 81. 
 of revolving bodies, N, 
 
 100. 
 
 drying machine, E, 53; G, 80. 
 governor, A, xv, 52. 
 
 Centripetal force, A, iv, 653; B, 159; 
 
 C,77,78;E,62; 
 
 G, 79; H, 105; I, 
 
 30; N, 94-100. 
 
 at earth's equator, 
 
 G, 83. 
 
 Champagne, why it sparkles, G, 181. 
 Chain pumps, see Pumps. 
 Charcoal, A, iv, 715 ; D, 1, 64, and n, 488. 
 why its marks stick to a wall, G, 25. 
 why black, G, 301. 
 Chart of isoclinal lines, E$ 794* 
 
 magnetic variations, E, 789. 
 Chemical action, what is it, K, 153. 
 
 attends voltaic action, 
 
 B, 421; D, I, 323. 
 causes light, K, 162. 
 magnetism, K, 
 
 162. 
 produces mecifanical 
 
 power, K, 397. 
 affinity, A, I, 163; v, 30, 35, 38, 40; 
 
 D, I, 5, 8, 12, 33; E, 35; 
 
 E, 900; G, 25. 
 
 Chemical affinity, apparent suspension 
 of, in electrolysis, 
 F, 237. 
 
 causes heat, K, 159. 
 motion, K, 152. 
 
 converted into elec- 
 trical force, K, 154. 
 
 counteracted by heat, 
 D, n, 1107. 
 
 distinguished from 
 solution, C, 871. 
 
 exalted by heat, D, 
 n, 1106. 
 
 exerted within mi- 
 nute distances only, 
 D, I, 8. 
 
 influence of mass 
 upon, A, V, 38; D, 
 II, 1089. Berthol- 
 let's theory of the, 
 D, n, 1090. Bun- 
 sen's experiments 
 on, D, n, 1094. 
 Gladstone's experi- 
 ments, D, n, 1091. 
 Debus's experi- 
 ments, D, II, 1095. 
 
 influence of pressure, 
 D, n, 1083. 
 
 its intensity definite, 
 D< I> 9. 
 
 nature, D, 1, 5, 12, 33. 
 
 occurs between dis- 
 similar bodies, D, 
 1,8. 
 
 produces change in 
 the properties of 
 Compounds, D, I, 
 9, 12. 
 
 referable to electric- 
 ity, F, 211. 
 
 resistance of, to elec- 
 trolysis, F, 238. 
 
 simple cases of, D, II, 
 1079. 
 
 suspended at low tem- 
 peratures, D, n, 
 1108. 
 
 varies between dif- 
 ferent elements, D, 
 1,9. 
 
14 
 
 Chemical affinity a very powerful force, 
 
 D, I, 8. 
 
 work done by, K, 226. 
 affinities, concurring, D, n, 1102. 
 attraction, see Chemical affinity, 
 combination, A, v, 39; E, 16; E, 
 
 748; J, 400. 
 electricity evolved in, 
 
 F, 236; J, 680. 
 laws of, D, 1, 13. 
 spontaneous or not, D, 
 
 1,11. 
 decomposition, J, 464. 
 
 application of spongy 
 platinum to, D, n. 
 1097. 
 
 produced by electric- 
 ity, K, 84. 
 produced by light, A, 
 
 xin, 290. 
 
 produced by thermo- 
 electricity, F, 262. 
 decomposition, theory of, N, 326. 
 
 coil, J, 795. 
 effects of current, J, 698. 
 
 discharge, J, 671 ; of pile, 
 
 E, 888. 
 
 force, see Chemical affinity, 
 harmonicon, J, 211. 
 rays, A, xin, 287. 
 
 of the sunbeam extinguished in 
 doing chemical work, A, ix^ 22. 
 mostly cut off by glass, A, ix, 24. 
 in spectrum, F, 305. 
 sources of heat, E, 748-757. 
 union by electricity, E, 856. 
 Chemistry, definition of, G, 9; J, 1. 
 of plants, K, 395. 
 relation to physics, C, 5; E, 9. 
 Cheval vapeur, J, 395. 
 Chevreul's classification of colors, E, 
 
 491. 
 Chimneys, draught in, E, 689; E, 
 
 717; G, 262; J, 402. 
 reversed draught, E, 690. 
 smoky, G, 262. 
 the tallest, A, '68, 110. 
 theory of, C, 541 ; G, 262. 
 Chi ad n Ps experiments, B, 216, 233; J, 
 
 216. 
 tonometer, M, 121. 
 
 Chordae vocalis, B, 246. 
 Chords musical, G, 196 ; M, 306. 
 
 dominant and subdomi- 
 
 nant, J, 193. 
 major and minor, J, 192. 
 physical constitution of, 
 
 J, 199. 
 
 Choroid, J. 495. 
 Chromatic aberration, see Light. 
 
 diagram, E, 465; scale, J, 194. 
 Chromatics, A, v, 197 ; E, 456. 
 Chronometer, A, v, 512; E, 596; 
 
 H, 106. 
 
 Cinematics, A, xi, 318. 
 Circuit, see Electric circuit. 
 Circular polarization, see Light. 
 Clang, definition of, M, 117. 
 Claque bois, formation of the, M, 137, 
 
 167. 
 
 Clarionet, tones of the, M, 195. 
 Cleavage, C, 205; D, i, 95; E, 72; E, 
 
 157. 
 planes of, C, 119, 204. 
 
 similar, C, 126, 175. 
 symbols of, C, 128. 
 tenninal and basal, C, 159. 
 Clement's disc experiment, F, 133. 
 Clepsydra, A, v, 336; G, 151; H, 117. 
 Climates, A, v, 342; B, 572; H, 118; 
 
 E, 947; G, 267; J, 866. 
 cause of dampness of English, L, 189. 
 influence of aqueous vapor on, J, 843. 
 mildness of European, L, 193. 
 Climatology, E, 947 ; J, 864-869. 
 Clinometer, A, v, 346. 
 Clocks, A, v, 357; A, '63, 427: B, 172; 
 
 C, 72; G, 58; J, 58. 
 why they go faster in winter than in 
 
 summer, G, 60. 
 Clothing, when warm and when cool, 
 
 G, 220; see Heat. 
 
 Clouds, A, v, 364; B, 596; E, 1068; 
 E, 978; G, 273; H, 121; J, 837. 
 average height of, G, 274. 
 cause of generation of, L, 402. 
 cirrus, G, 275; J, 837; cirrocumu- 
 
 lus, J, 839. 
 cirrostratus, J, 839. 
 classification of, E, 979. 
 composition of, L, 195. 
 constitution of, F, 207. 
 
15 
 
 Clouds, cumulus, G, 275: J, 838; 
 
 cumulo-stratus, J, 839. 
 electricity of, A, v, 368; F, 207; J, 
 
 855. 
 
 formation of, G, 274 ; I, 248 ; J, 839. 
 how different from fogs, G, 273. 
 Howard's names for, J, 837. 
 nimbus, G, 277. 
 rain, J, 838. 
 reflect sound, M, 18. 
 stratus, G, 277. 
 variety of, G, 275. 
 what are, G, 273. 
 
 whv float in the atmosphere, G, 274. 
 why red at sunset, G. 337. 
 Coal, amount equivalent to the working 
 
 power of a man, G, 251. 
 mechanical power in, G, 251. 
 Coefficient of friction, B, 175. 
 Coercive force, E, 881. 
 Cogs, see Wheels, teeth of. 
 Cohesion, A, i, 124, v, 437; C, 119, 
 342 ; D, I, 5, 33, 52 ; E, 32 ; F, 
 57 ; G, 25 ; H, 125, 175 ; I, 65 ; J, 
 61; K, 171. 
 
 characters of, D, i-, 5, 52. 
 coefficient of, on chemical action, D, I, 
 
 52 ; D, n, 1080. 
 of fluids, E, 148. 
 force of, lessened by heat, L, 75. 
 of liquids, D, I, 54; E, 148. 
 measure. of, in solids, E, 33. 
 modified results of, E, 40. 
 not the cause of the sticking of two 
 
 pieces of ice, L, 335. 
 and repulsion, E, 146. 
 of solids. D, I, 53; E, 147. 
 of water increased by removal of 
 
 gases, L, 126. 
 Cohesive attraction, see Cohesion. 
 
 force of different materials, see Ingra- 
 ham's " Concise System of Mathe- 
 matics." 
 
 Coil, primary, J, 764. 
 Henry's, D, I, 400. 
 Ruhmkorffs, J, 794; condenser of, 
 
 J, 793. 
 
 effects of, J, 794-797. 
 Cold, A, ix, 16, v, 458; F, 360; G, 211. 
 
 Compare Heat and Cooling, 
 absolute, A, ix, 19. 
 
 Cold, apparent radiation of, C, 651 ; E, 
 
 575; E, 634. 
 reflection of, D, I, 200 ; J, 
 
 355; L, 282. 
 causes of, A, v, 458. 
 of central Asia, cause of, L, 405. 
 conduction of, L, 228. 
 effect of, on a thermo-electric pile, 
 
 L, 16. 
 
 extreme of E. coast of America, L, 193. 
 indicated by the deflection of a mag- 
 netic needle, L, 16. 
 most intense, yet obtained, A, ix, 18, 
 
 20; G, 211. 
 natural, G, 211. 
 
 a negative property, D, i, 164; G, 206. 
 produced by carbonic acid and ether, 
 
 D, 1,253; L, 179. 
 dissolving salt and sugar, 
 
 L, 165. 
 sulphate of 
 
 soda, L, 166. 
 
 electric current, D, i, 410. 
 escape of compressed air, 
 
 L, 46. 
 evaporation, E, 681; 
 
 J, 288. 
 of alcohol, 
 
 L, 168. 
 of ether, L, 
 
 168. 
 expansion of gases, J, 
 
 408. 
 heat becoming latent, 
 
 (examples), I, 237. 
 during the passage from 
 the liquid to the gas- 
 eous state, L, 168. 
 during the passage from 
 the solid to the liquid 
 state, L, 166. 
 nocturnal radiation, J, 
 
 407. 
 
 rarefaction, L, 44. 
 stream of carbonic acid, 
 
 L, 170. 
 
 stretching wires, L, 101. 
 voltaic discharge, F, 225. 
 production of intense, D, I, 253. 
 regarded dynamically, K, 48. 
 of snow and salt, L, 166. 
 
16 
 
 Cold of solid carbonic acid, D, I, 253; L, 
 
 171. 
 
 sources of, I, 257 ; J, 406, 407. 
 < 'oil i mat inn. J, 700. 
 Collision of atoms, heat and light pro- 
 duced by, L, 64, [compare 
 Atoms]. 
 
 bodies, A, xi, 325 ; J, 37. 
 effects of, K, 29. 
 
 of elastic bodies, C, 196; F, 78; N,115. 
 formula for, C, 196- 
 
 198. 
 non-elastic bodies, C, 49; N, 114. 
 
 formula for, C, 
 
 49-51. 
 
 Colloids, A, xvi, 729; J, 105. 
 Color blindness, A, v, 500; E, 799; 
 
 E, 490; F, 357; J, 529, 771. 
 depends on temperature, E 768. 
 influences the radiation of heat, G, 
 
 223; L, 302. 
 
 and music, analogy between, G, 338. 
 physical cause of, G, 326 ; L, 272. 
 of sky, possible cause of, B, 608 ; L, 
 
 408. 
 Colored figures, N, 249. 
 
 polarization, see Light, polarization of; 
 
 rings, see Light, polarized. 
 Coloring matters, absorbed by bone 
 black, etc., A, 
 nr, 482. 
 adjective, D, in, 
 
 546. 
 substantive, D, in, 
 
 546. 
 Colors, A, v, 197, 494; B, 287; F, 279; 
 
 H, 130; .1,3. 
 accidental, A, v, 497; F, 356, 357; I, 
 
 318; N, 248. 
 analysis of, E, 769; E, 458. 
 
 by absorption, E, 771. 
 appreciation of E, 799. 
 Chevreul's classification of, E, 800; 
 
 E, 491. 
 
 compared with sounds, F, 279. 
 complementary, A, v, 497 ; B, 289 ; D, 
 I, 134; E, 772; E, 459; F, 301; 
 G, 331; H, 131; 1,318; J, 449. 
 of compressed glass, J, 563. 
 contrast of, A, v, 497; B, 313; G, 332. 
 
 Colors, dark, are the best absorbers of 
 
 heat, G, 225. 
 
 of diffraction, F, 308; I, 318. 
 explained, N, 241. 
 
 of grooved plates, E, 845; E, 535. 
 of heat, J, 354. 
 influence on one another's appearance, 
 
 see Contrast of. 
 iridescent, D, i, 144. 
 of natural objects, on what dependent, 
 
 G, 330. 
 
 Newton's theory of, D, I, 134. 
 of opaque bodies, I, 316. 
 primary, E, 769 ; F, 299. 
 production of, F, 301. 
 
 by interference, D, i, 144. 
 of polarized 
 light, J, 
 556-558. 
 scale of, F, 312. 
 simple, G, 329; .1,465. 
 of small particles, F, 313. 
 spectral, see Colors, accidental, 
 of spectrum, see Spectrum, 
 study of, E, 801 ; E, 492. 
 subjective, see Colors, accidental, 
 table of (Newton's), F, 311. 
 of thick plates, F, 313. 
 
 thin plates, B, 335; E, 529; F, 
 
 311; J, 547; N, 241. 
 
 transom-lit bodies, I, 318; of un- 
 
 annealed glass, J, 563. 
 variable, A, v, 499. 
 vegetable, action of spectrum on, D, 
 
 n, 1149. 
 Column, A, v, 522; G, 121. 
 
 height of, how measured, G, 121. 
 Columnar structure, A, v. 524. 
 Columns, resistance to pressure, E, 
 
 171. 
 Combination, chemical, see Chemical 
 
 combination. 
 Combining proportions, see Chemical 
 
 combination, 
 volume, aids in fixing the chemical 
 
 equivalents, D, n, 1152. 
 volume of a gas, D, n, 465. 
 volumes, law of, A, v, 40. 
 Combustion, A, v, 529 ; J, 400. 
 analysis of, L, 58. 
 
17 
 
 Combustion of bisulphide of carbon by 
 compression of its va- 
 por, L, 71. 
 a candle, L, 60. 
 candles on Mt. Blanc, L, 
 
 63. 
 cause of heat in, E, 
 
 750. 
 
 due to collision of atoms, L, 65. 
 effect of height on, L, 63. 
 Frankland's experiments upon, L, 63. 
 heat from, see Heat, 
 influence of aqueous vapor on, A, v, 
 
 531. 
 sunlight on, A, v, 531; 
 
 A, ix, 24. 
 
 key to the phenomena of, K, 321. 
 more intense in condensed air, A, v, 
 
 531. 
 
 i rapid in winter, A, v, 531. 
 nature of, D, n, 444. 
 no matter destroyed in, D, II, 11, 445, 
 products vary with the temperature, 
 
 D, n, 1107. 
 
 and respiration, products of, E, 691. 
 
 smouldering, produced by platinum 
 wire, D, n, 635. 
 
 spontaneous, A, v, 532 : D, n, 446. 
 
 a source of heat, see Heat. 
 
 theory of, L, 64. 
 
 Comets, Mayer on, H, 131 ; K, 270. 
 Communicating vessels, B, 89. 
 Communicator, J, 758. 
 Commutator, J, 753, 779. 793. 
 Compass, A, v, 571; B, 357; G, 424; 
 H, 135; 1,369; J, 586, et seq. 
 
 azimuth, A, v, 572; inclination, J, 
 589. 
 
 mariners, B, 357; D, I, 264; E, 882; 
 
 E, 787; G, 424; J, 588. 
 needle, F, 156; N, 271. 
 solar, A, v, 573. 
 
 sine, see Galvanometer, 
 tangent, B, 443; J, 702. 
 variations of, A, v, 572 ; D, I, 270 ; F, 
 
 157, et seq. 
 
 when discovered, G, 426. 
 Compensation pendulums, see Pendu- 
 lums. 
 Complementary colors, see Colors. 
 
 Composition of forces, see Forces, 
 of velocities, Galileo's proposition, C, 
 
 28. 
 
 Composite eyes, B, 297. 
 Compound blowpipe, see Blowpipe. 
 
 pendulum, see Pendulum. 
 Compressed air, etc., see Air, etc., com- 
 pressed. 
 
 Compressibility, A, v, 579; B, 30; C, 
 113 ; E, 23, 236 ; E, 21 ; H, 136 ; 
 G, 16; I, 18; J, 37. 
 of alcohol, D, I, 34. 
 
 gases, E, 274; J, 131. 
 
 fluids, F, 105. 
 
 liquids, E, 188; J, 69; D, I, 34 
 
 (table); N, 119. 
 
 solid matter, C,113; N, 19 or 119. 
 Compressing machine, E, 368 ; E, 
 
 288. 
 Compression, A, v, 579; of air, see 
 
 Air. 
 
 apparatus for (CErsted's), E, 236. 
 of bisulphide of carbon vapor, L, 71, 43. 
 
 gases, see Gases, 
 heat resulting from, see Heat. 
 Concert pitch, J, 195. 
 Concord, A, vni, 729; E, 456; F, 145; 
 
 G, 196. 
 
 perfect, E, 457, 
 Concordant tones, J, 192. 
 Concrete, A, v, 592. 
 Concretionary structure, A, v, 595. 
 Condensation, causes, G, 238; I, 238. 
 of carbonic acid, C, 596, 609. 
 congelation and combination, mechan- 
 ical value of each in the case of 
 water, L, 162, et seq. 
 and congelation promoted by water in 
 
 its different states, L, 403. 
 of gases, F, 51 ; see Gases, 
 when gases combine, law of, D, r, 22, 
 
 in, 760. 
 
 of vapors, J, 292. 
 Condenser, A, v, 597; B, 396; N, 156; 
 
 J, 642, 647. 
 advantage of, N, 219. 
 of vEpinus, E, 844. 
 Liebig's, D, i. 236; E, 643 ; J, 294. 
 of RuhmkorfPs coil, J, 793. 
 of steam engine, see Steam engine. 
 
18 
 
 Condensing syringe, B, 139; C, 333; D, 
 
 1,39; F, 127; I, 134, J, 154. 
 Conductors of Electricity, Heat, etc., 
 
 see Electricity, Heat, etc. 
 Congelation, F, 371; H, 143; I, 221; 
 
 see Freezing and Solidification. 
 Congelation of water and mercury in 
 
 a vacuum, I, 237. 
 Conjunctive wire, E, 1009. 
 Consecutive poles, see Magnet. 
 Conservation of Force, see Force, etc. 
 Consonance, theory of, M, 292, 298. 
 Contact, theory of, B, 436. 
 Contracted vein in die efflux of gases, 
 A, xui, 413. 
 efflux of liquids, 
 A, ix, 415 ;F, 
 130; see vena 
 contracta, 
 
 Contraction, compare Expansion, 
 of beeswax in cooling, L, 118. 
 curves of, of liquids, on cooling, D, I, 
 
 167. 
 
 force of, A, ix, Hi. 
 results from solidification, L, 118, 
 more rapid near the point of solidifi- 
 cation, A, ix, 16; xv, 430. 
 of India-rubber by l*eat, L, 102. 
 Contractions of fluid currents, F, 130. 
 Contrast of colors, see Colors. 
 Convection of Heat, etc., see Heat, etc. 
 Cooling, compare Heating, Heat and 
 
 Cold. 
 
 contractile force of, L, 98. 
 Dulong and Petit's method, J, 371. 
 effect of air and hydrogen on heated 
 
 bodies, L, 254. 
 
 an effect of rarefaction, L, 45. 
 hastened by coating substance with 
 
 good radiators, L, 303. 
 and heating, laws of, F, 365, 
 a loss of motion, L, 258. 
 method of, J, 371. 
 Newton's law of, D, i, 202^ E, 573 ; 
 
 J, 330. 
 by radiation, Dt, i, 202; E, 573,- E, 
 
 632; F, 378; L, 401. 
 when produced, L, 273. 
 Copper, tempering of, E, 178. 
 Cordage, strength of, on what dependent, 
 G, 113. 
 
 Cork, why it floats, G, 43. 
 Cornea, B, 298; G, 349; J, 513. 
 Cornet, A, v, 726. 
 Coronas, E, 841 ; E, 537. 
 Corpuscular theory, see Light. 
 Correlation of forces, see Forces. 
 Corti's fibres, M, 324. 
 Cosmogony, Grove on, K, 81. 
 Coughing, sound of, how produced, G, 
 
 204. 
 
 Coulomb's balance, see Balance, torsion. 
 Couple of forces, J, 21. 
 mechanical, N, 32. 
 
 definition of, C, 47 ; H, 149. 
 formula for, C, 47. 
 terrestrial, J, 583. 
 thermo-electric, J, 812. 
 Couples, E, 48. Couronne des Tas- 
 
 ses, J, 686. 
 
 Cowls, E, 698; E, 725. 
 Crane, A, vi, 35; G, 105. 
 Crank, A, vi, 36; G, 110. 
 Cream, why it rises on milk, G, 147. 
 Crevasses in glaciers, due to what, L, 214. 
 
 prove ice non viscous, L, 214, et seq. 
 Crucible, A, vi, 105; lime, A, '66, 100. 
 Crying, what is, G, 206. 
 CryophoriiA or frost bearer, B, 635 : C, 
 609; D, I, 229; F, 373; H, 150; L, 
 169. 
 Crystalline forces, direction of, E, 77; 
 
 J, 614. 
 forms, C, 119, 127; E, 163, 158. 
 
 constancy of, C, 183; E, 75. 
 definitions of, C, 119; E, 63. 
 dominant and secondary, C, 130. 
 essential and accidental, C, 119. 
 hemihedral, C, 128; J, 614. 
 holohedral, C, 127. 
 tetrartohedral, C, 129, 156. 
 lens, see Lens, 
 molecules, equality of axes in, E, 78; 
 
 shape of, E, 76. 
 structure, C, 119. 
 
 developed by cleavage, D, I, 
 
 95 ; solution, D, I, 94. 
 development of, E, 84. 
 produced by successive 
 
 heatings, D, I, 95. 
 produced by vibration, D, I, 
 95; E,63. 
 
19 
 
 Crystalline symmetry, C, 132. 
 systems, C, 121, 175; E, 54-69. 
 system dimetric, C, 142; E, 55; 
 modified forms of, E, 69, 70. 
 hexagonal, C, 147; E, 59; 
 modified forms of, E, 69, 70. 
 monoclinic, C, 163; E, 57; 
 
 modified forms of, E, 67. 
 monometric, C, 132; E, 54; 
 modified forms of, E t 
 61,62. 
 
 triclinie, C, 168; E, 58; 
 modified forms of, E, 65, 66. 
 trimetric, C, 158. 
 Crystallization, B, 78; D, i, 91; I, 222; 
 
 N, 17. 
 
 conditions of, E, 79. 
 by feeble currents, E, 893. 
 development of heat during, E, 88; 
 
 of light, D, i, 117; E, 89. 
 from gaseous state, E, 81. 
 influence of light upon, D, II, 1132. 
 by liquefaction, E, 80. 
 phenomena of, N, 17. 
 process of, C, 119. 
 salts separated by, E, 85. 
 sudden, E, 86. 
 temperature of constant, under same 
 
 pressure, L, 105. 
 Crystallizing, changes caused by, E, 
 
 87. 
 Crystallography, A, vi, 116; B, 79; 
 
 C, 119, 121; E, p. 27; E, 151. 
 Crystalloids, A, xvi, 729 ; J, 105. 
 Crystals, action of, on colored light, F, 
 
 317. 
 
 axes of, C, 121, 123; D, I, 100. 
 biaxial, D, i, 149. 
 centre of, C, 124. 
 change of bulk in formation of, D, 
 
 I, 94. 
 
 classification of D, I, 101. 
 cleavage of, C, 119, 204. 
 coloi-ed rings in, see Light polarized, 
 compound, E, 71. 
 
 conduct heat, C, 656 ; E, 616 ; L, 232. 
 definition of, C, 121. 
 definite forms of, D, i, 91. 
 deposition on nuclei, D, I, 93. 
 determination of, C, 176. 
 dichroism of, F, 343. 
 
 Crystals, difference of conductivity in 
 
 different directions, C, 656; L, 232. 
 
 doubly refracting, D, i, 148; F, 316; 
 
 J, 538. 
 inclination of axis, 
 
 F, 317. 
 elasticity of, Savart's experiments, C, 
 
 196. 
 
 expansion of, C, 498 ; J, 243 ; L, 101. 
 forms of, E, 153, 158; modified, C, 
 
 131, 175; E, 60. 
 groups of, C, 173. 
 growth of, E, 52. 
 irregularities of, C, 170. 
 modes of obtaining, D, i, 91. 
 models of, C, 132. 
 planes of, C, 121. 
 parameters of planes of, C, 124. 
 positive and negative, D, I, 148 ; E, 
 
 551; E, 857; F, 317; J, 539. 
 principal form of, C, 143, 151, 153, 159. 
 section of, D, i, 149, note ; F, 
 
 315. 
 
 replacement of edges, D, i, 97- 
 similar axes of C, 125 ; planes of, C, 
 
 126. 
 simple and compound forms of, C, 129; 
 
 D, i, 96. 
 size of, C, 121. 
 of snow, L, 196. 
 symbols of, C, 128. 
 systems of, C, 121, 175. 
 truncation of angles of, D, I, 97. 
 twin, C, 173. 
 
 unequally expanded by heat, D, I, 165. 
 uniaxial, D, I, 149; J, 539, 540. 
 Cube, Leslie's, J, 335. 
 Cubic expansion, B, 490; E, 590. 
 Cubit, A, vi, 129. 
 
 Culinary paradox, E, 677; E, 632. 
 Cupel, A, vi, 148. 
 Cupping glass, principle of, D, I, 46; G, 
 
 175. 
 
 Current affinity, D, n, 1123. 
 Currents, aerial, F, 133. 
 
 how produced, L, 182. 
 in upper and lower at- 
 mosphere, L, 183. 
 
 of air, escape under pressure, F, 133. 
 excited by electric discharge, 
 F, 189. 
 
20 
 
 Currents of air and gases, E, 716. 
 
 produced by ice, E, 
 697; E, 724. 
 
 caused by heat, A, ix, 18. 
 
 electrical, see Electric currents. 
 
 gaseous, properties of, F, 132. 
 
 Bernouilli's formula for the 
 velocity of, F, 133. 
 
 general law of, F, 130. 
 
 Henry's, E, 1035. 
 
 lateral, reaction of, F, 130. 
 
 oceanic, A, xi, 418; E, 628. 
 Curve, ballistic, E, 145. 
 
 influence in capillarity, E, 236. 
 
 of liquid surfaces, E, 234; .1, 100. 
 
 of swiftest descent, E, 76. 
 Curvilinear motion, E, 51. 
 Cut off, A, xv, pp. 65, 58; C, 633; E, 
 
 712. 
 
 Cyanometer, A, vi, 177. 
 Cyanotype, F, 391. 
 Cycloids, A, vi, 178. 
 Cyclone, A, vi, 178; E, 968. 
 Cylinder, A, vi, 186. 
 Cylinders, strength of, F, 53; G, 118. 
 
 Daguenrotype, A, xin, 287; B, 344; 
 D, n, 1143; F,389; G,345; H, 157; 
 I, 347 ; J, 499. 
 
 application of mercury to, D, n, 1143. 
 development of, D, II, 1143. 
 printing from a, I), n, 1145. 
 Dalton's law, H, 159. 
 Dampness of Great Britain, cause of, L, 
 
 189. 
 Darkness made light, K, 119. 
 
 by interference of light, F, 306. 
 Day, apparent, J, 10. 
 
 variation in length of the, K, 303. 
 Dead point, G, 112. 
 Decay restores heat to the universe, K, 
 
 419. 
 
 Decimetre, E, 18; J, ll. 
 Declination, B, 354; E, 883; J, 498. 
 change of, N, 275. 
 magnetic, B, 354; E, 788; F, 157; 
 
 G, 426; J, 584; N, 273. 
 of a star, J, 498. 
 Decolorizers, A, in, 482. 
 Decomposition, chemical, see Chemi- 
 cal decomposition. 
 
 Deflagration, D, n, 732; E, 88(5. 
 Deflagrator, Hare's, E, 973; J, 686, 
 
 711. 
 
 Deliquescence, D, n, 458, note. 
 Densimetre, J, 97. 
 Density, A, vi, 391; B, 39; C, 18; E, 
 
 260; E, 98; G, 15; J, 11. 
 changed by tension, E, 169. 
 of earth, E, 141 ; E, 102 ; J, 43. 
 
 M:i<kelyne's experiment, J, 
 
 42. 
 
 of gases, E, 552-553; E, , 611. 
 liquids, E, 267-269. 
 matter, A, xi, 318; F, 52. 
 maximum of different solids, E, 261- 
 
 266. 
 solutions, E, 
 
 544. 
 
 water, E, 542 ; L, 93. 
 relation to weight, C, 91. 
 specific, F, 113. 
 
 of vapors, E, 657-658 ; E, 693. 
 and weight, formula for, C, 91. 
 Derrick, A. vi, 35; G, 105. 
 Descent of bodies, see Falling bodies. 
 Despretz's experiments, E, 275. 
 Deviation of light twice reflected, E, 
 
 423. 
 the sine of the vertical, H, 
 
 163. 
 
 Dew, A, VI, 432: B, 595; E, 1075; E, 
 975; F, 379; G, 270; H, 163; I, 
 251; J, 846; L, 401. 
 cannot properly be said to fall, G, 
 
 271. 
 cause of, E, 1076; L, 401. 
 
 deposition of, L, 416. 
 a clear sky and calm damp atmos- 
 phere necessary for its copious 
 formation, G, 271 ; L, 419.' 
 is the condensation of the atmospheric 
 vapor on bodies chilled by radia- 
 tion, C, 653; L, 416-418. 
 falls on what, E, 976; E, 1077; G, 
 
 271. 
 
 still night required by, L, 420. 
 theory of, C, 653; D, I, 200; G, 270; 
 
 L, 407. 
 
 (Well's), J, 847 ; L, 415, et seq. 
 Melloni's addition to the, L, 
 421. 
 
21 
 
 ^y 
 
 
 
 '%, *j 
 
 
 Dewed substances colder than undewed 
 
 ones, L, 417. 
 better radiators than 
 nndewed ones, L, 
 417. 
 
 Dew-drop, why globular, G, 30. 
 Dew-point, B, 592 ; C, 641 ; D, i, 247 ; 
 E, 626; E, 674; F, 374; G, 270. 
 Diacaustic, see Caustic. 
 Dial, sun, A, vi, 440. 
 Dialysis (see Diffusion), A, xvi, 729; 
 
 A, '65, 307; J, 106. 
 Dialyser, J, 106. 
 Diamagnetism, see Magnetism. 
 Diamond, changed to graphite by elec- 
 tric arc, D, II, 483. 
 cutting of the Kohinoor, D, II, 482, 
 
 note. 
 
 jar, E, 852. 
 
 nature and properties of, D, II, 481. 
 Newton's opinion of, L, 58, 
 Diapason, E, 460 ; E, 377 ; J, 195. 
 
 natural, E, 395. 
 
 Diaphragms porous, use in voltaic ar- 
 rangements, D, I, 33, 339. 
 Diaphragm cells, double, D, n, 1111. 
 Diathermancy, A, vi, 449 ; A, ix, 17 ; 
 D, I, 204 ; E, 641 ; F, 380 ; H, 171 ; 
 J, 348; K, 278. 
 
 applications, E, 647 ; E, 589. 
 explained and illustrated, L, 310. 
 of iodine dissolved in bisulphide of 
 
 carbon, L, 366. 
 
 how modified, E, 587 ; E, 645. 
 is not transparency, A, vi, 449; L, 321. 
 of rock salt, D, I, 206; F, 382. 
 Diathermanous bodies, table of, D, i, 
 
 207 ; F, 381. 
 
 Diatonic scale, M, 307; N, 191. 
 Dichroism, see under Crystals. 
 Dielectrics, D, i, 276; F, 177; H, 172; 
 
 J, 629. 
 
 Difference tones, M, 281. 
 Differentiation in development of the 
 
 animal body, K, 409. 
 Diffraction of light, see Light. 
 Diffusion, analysis by, A, xvi, 729. 
 of gases, see Gases, 
 liquids, see Liquids, 
 motion requires time, E, 130. 
 sound, F, 139. 
 
 Diffusion, use of, A, '65, 307. 
 
 tube, D, i, 83. 
 Digester, Papin's, A, xv, 48; B, 528; 
 
 D, I, 229; H, 181; I, 234; J, 286. 
 Dilatation, see Expansion. 
 Dimorphism, C, 184; D,i, 111; E, 91 
 
 temperature affecting, E, 92. 
 Dioptrics, A, XIT, 537; B, 270; E, 
 
 438; G, 318; H, 182; L, 286. 
 Diorama, I, 340. 
 Dip, A, vi, 493 ; A, XI, 64 : J, 589 ; H, 188. 
 
 intensity of, Krafft's law, F, 160. 
 Dipping needle, B, 358; D, i, 270; E, 
 886;E,793; F,158; 
 G, 425; 1, 370; J, 589; 
 N, 276. 
 
 Biot T s, E, , 888. 
 Disc, B, 66. 
 
 Discharge electric, see Electric dis- 
 charge. 
 
 Discord, E 456 ; F, 145 ; 6, 196. 
 Discovery, conditions of, K, 104. 
 Dispersion of light, see Light. 
 Displacement, collection of gases by, 
 
 D, n, 465, 475. 
 
 of zero point, E, 573. 
 Dissolving views, A, xi, 56; G, 368; I, 
 
 338. 
 
 Dissonance, E, 456; F, 145. 
 due to beats, M, 298, 301. 
 graphic representations of, M, 305. 
 Distance, appreciation of, A, xvi, 132 ; 
 
 IJ, 481. 
 
 calculated by sound, E, 346 ; F, 140. 
 
 of distinct vision, p, 478. 
 
 Distillation, C, 588; D, i, 235; E, 
 
 641 ; E, 686 ; G, 242 ; 1, 240 ; J, 292. 
 
 apparatus for, E, 687 ; fractional, 
 
 E, 644. 
 
 Distribution of land and water, J, 868. 
 
 Dividing engine, A, vi, 517; C, 443. 
 
 Diving bell, A, vi, 520; H, 71. 
 
 Divisibility of matter, A, iv, 162, VI, 
 523; xvi, 493; 
 B, 29; C, 109; 
 D, i, 4; E, 
 13, 14, 22 ; E, 
 19;F,40,49, 
 52; G, 13; H, 
 191; I, 17; J, 
 3-5; N, 16. 
 
 
22 
 
 Divisibility of matter limited, N, 17. 
 
 in solution, N, 16. 
 Dobereiner's lamp, J, 399. 
 Domes, A, vi, 558; N, 79-81. 
 Doppler's theory, M, 78. 
 Double diatonic scale, E, 373. 
 
 refraction, see Light. 
 
 touch, method of, N, 272. 
 Doublet, Wollaston's, J, 482. 
 Dove's law of storms, J, 837. 
 Dovetailing, G, pp. 117, 118. 
 Drainage, principles of, G, 152. 
 Draught of chimneys, see Chimneys. 
 Drops in conical tubes, E, 241. 
 
 movement of, between laminae, E, 
 295. 
 
 prescription of medicine by, unsafe, 
 
 G, 29. 
 Drummond light, A, in, 384; vi, 629; 
 
 D, n, 472; J, 507. 
 Drying machine, E, 53. 
 
 tubes, difficulties in selecting and ob- 
 taining, L, 347. 
 
 Duboscq's electric lantern, E, 884. 
 
 Dub's laws, E, 915. 
 
 Ductility, A, vi, 648; C, 205; D, I, 54, 
 55,,and n, 668; E, 44; E, 175; 
 G, 26; H, 193; I, 71; J, 3, 67; 
 order of, C, 207. 
 
 Duhamel's experiment, J, 189. 
 
 Dulcimer, A, vi, 644. 
 
 Dust, theory of beating from clothes, 
 G, 20. 
 
 Dyeing, D, in, 547. 
 
 Dynamics, A, vi, 702, xi, 318; C, 34; 
 
 E, 39; F, 71; H, 194. 
 defined, N, 21. 
 
 Mayer's essay upon celestial, K, 259. 
 Dynamic energy defined, L, 151. 
 
 radiation and absorption, discovery of, 
 
 L, 380. 
 of gases, table, 
 
 L, 383. 
 
 in tubes of dif- 
 ferent lengths, 
 L, 389. 
 
 of vapor of bo- 
 racic ether (ta- 
 ble), L, 387. 
 of vapors in 
 tubes, L, 386. 
 
 Dynamical theory of heat, see Heat. 
 Dynamometer, Le Roy's, E, 183. 
 
 Reynier's, E, 184. 
 
 Dynamometers, A, vi, 702; E, 182, 
 183, 184; E, 37; G, 89; H, 198. 
 Dynamite, A, '68, 223. 
 
 Ear, B, 248; E, $ 478-481; E, 393; G, 
 
 pp. 201, 202; H, 200. 
 nerve of, B, 251 ; M, 2, 323. 
 otolithes of, M, 324. 
 sensibility of, E, 461; E, 378; H, 
 
 200. 
 trumpet, E, 359; G, 200; I, 168; J, 
 
 184; N, 186. 
 Earth, A, '62, 393. 
 
 age of, K, 245; L, 444. 
 
 cause of present form of, G, 83. 
 
 centre of gravity of, C, 84. 
 
 circuit, E, 1027; E, 922. 
 
 acommon electrical n^crvuir, K, 911. 
 
 crust of, thicker than often supposed, 
 
 L, 94, 119. 
 density of, E, 141 ; E, 102; F, 66; 
 
 H, 204; J, 43. 
 
 directive power of, E, 911; F, 161. 
 eccentricity of, C, 83. 
 energies of, all due to the sun, L, 445, 
 
 falling into the sun, L, 67, 443. 
 form of, C, 85; E, 138; F, 67-72; H, 
 202; J, 60; K, 297; heat of, see 
 Heat. 
 heat which would be generated by 
 
 stopping its motion, L, 57. 
 heat equivalent of gravity of, and sun, 
 
 L, 57, 443. 
 
 of rotation of, L, 443. 
 how proved to be in motion, G, 84. 
 magnetism of, see Magnetism. 
 mass of, H, 200. 
 poles of, J, 63, 590. 
 rotation of, L, 439; and tides, E, 
 
 164; H, 200; L, 443. 
 trade winds, L, 183. 
 spheroidal figure of, C, 83, H, 202. 
 temperature of, H, 205. 
 volume of, diminished, K, 303. 
 Earthquake, A, vi, 720; B, 361; H, 
 
 207; L, 186. 
 Earth's attraction, law of, see Gravity. 
 
23 
 
 Ebiillioscope, A, vi, 737. 
 Ebullition, A, vn, 346, xv, 44; D, i, 
 222; E, 675; F, 371-373; G, 241; 
 H, 207; I, 229; J, 269; L, 129, 130. 
 Compare Boiling point, 
 explosive, L, 126. 
 influence of pressure on, See Boiling 
 
 point. 
 
 Eccentric, A, vi, 738; J, 388; N, 215. 
 Echo, A, vi, 740; B, 224: E, 353; E, 
 | 434; F, 142; G, 197; I, 162; J, 
 182, 183; M, 17, 20; N, 183; H, 
 209. 
 
 on the clouds, M, 18. 
 
 Echoes remarkable, B, 225 ; E, 435 ; 
 E, 354; G, 198; M, 17-20; N, 
 184, 185. 
 
 tone changed by, E, 355. 
 when multiplied, G, 198; E, 435. 
 where most frequent, G, 198. 
 Ettervesceiice, A, vu, 26, 
 Efflorescence, A, vn, 26; D, n, 458. 
 Efflux, B, IbO; E, 223, 224,283; J, 
 
 165. 
 
 Effusion of gases, J, 107. 
 Egg shell, illustrates principle of the 
 
 arch, G, 120. 
 Elastic bodies, A, vn, 50; J, 3-8; L, 
 
 73; N, 113. 
 
 collision of, C, 1A6 ; E, 
 132, 133; E, 182; 
 F, 78; G, 68; L, 73; 
 N, 114-117. 
 curve, A, vn, 50. 
 fluids, B, 116: D, I, 36; E, 235; E, 
 
 252; F, 121; J, 110. 
 force, see Elasticity. 
 
 Elasticity, A, vii, 50, xi, 318 ; B, 72, 
 125; 0, 115, 186; D, I, 33; E, 26, 
 45; E, 160-188; F, 42,55; G, 
 22; H, 222; J, 3-8, 110; N, 20, 113. 
 affected by temperature, E, 47. 
 of air, D, I, 39, 40; F, 128; N, 157. 
 of billiard balls, C, 201. 
 coefficient of, C, 186; N, 114. 
 of compression, C 187; E, 160. 
 crystals, C, 195. 
 flexure, C, 187-189; E, 162. 
 gases, D, I, 35; E, 252; J, 110- 
 influence of, on affinity, D, n, 1081. 
 
 Elasticity, law of (Coulomb's), C, 192; 
 
 D, I, 33, 35. 
 
 limits of, C, 115, 193; E, 168. 
 
 of liquids, B, 115; C, 115,215; D, I, 
 
 34; E, 188; F, 104; H, 222. 
 modulus of, A, vn, 50, xi, 318 ; E, 
 
 18S ; J, 64. 
 
 of metals, E, 161, table, 
 perfect and imperfect, C, 115. 
 solids, C, 116, 185; D, I, 34; E, 159. 
 of tension, C, 185, 186 ; E, 160 ; J, 63. 
 
 torsion, C, 191, 193 ; E, 165 ; J, 64 ; 
 N, 20. 
 
 of traction, J, 63. 
 varieties of, C, 115. 
 
 of vapor, D, I, 255 ; J, 269 ; N, 210. 
 Elective power possessed by bodies with 
 
 regard to rays of heat and light, L, 
 
 308, et seq. 
 Electric animals, E, 1046. 
 
 apparatus, A, '63, 427; A, vn, 62; F, 
 
 204. 
 
 arc, J, 712. 
 attraction and repulsion, E, 812, 842; 
 
 E, 908, 918-921, 930-940; F, 169, 
 188; G, 370; J, 615. 
 
 battery, see Battery. 
 
 bells, E, 940; B, 842; G, 385; N, 
 
 293. 
 blasting, E, 937; J, 674, 709; burr, 
 
 N, 308. 
 
 cannon, I, 404. 
 cascade, E, 948 ; E, 935. 
 charge, F, 197 ; J, 651. 
 
 and discharge, F, 192. 
 how distributed, D, I, 2S3, 
 does not reside in coating of 
 
 jar, F, 197. 
 
 of the electric battery, F, 196. 
 penetrates substance of dielec- 
 trics, F, 194. 
 ratio of intensity to surface 
 
 exposed, F, 195. 
 residual, F, 197. 
 tension of, F, 201. 
 chaining, F, 1S2; J, 660. 
 chiKies, I, 395; J, 645; coatings, J, 
 
 54. 
 
 circuit, G, 401 ; D, I, 317, 345, 333. 
 clocks, E, 328 ; J, 761, 
 
24 
 
 Electric column, A, vn, 68. 
 
 condenser, D, I, 290; E, 942; E, 
 845; F, 202; H, 138; I, 
 406-409. 
 discharge of the, E, 943 ; 
 
 I, 409. 
 
 condensing force, ,T, 651. 
 conduction, see Electricity, conduc- 
 tion of. 
 
 communication, J, 629. 
 couple, J, 681. 
 
 currents, D, I, 397; E, 916; E, 
 
 902; F, 227-237; G, 429; 
 
 I, 436, 452; J, 681-696, 
 
 811-815; L, 32; N, 308. 
 
 action of, on soft iron, D, I, 
 
 381. 
 
 magnets, D, I, 
 318, 379; F, 
 240; I, 452; 
 J, 729-736. 
 constant, J, 688, 693. 
 convection of, F, 227, 237. 
 direct and inverse, D, I, 397. 
 direction of, L, 32. 
 effects of, I, 472. 
 extra, E, 1036. 
 floating, E, 1015-1018; E, 
 
 909. 
 
 heat from, is proportional to 
 
 the resistance, L, 117-225. 
 
 increased by cooling the 
 
 conducting wire, L, 227. 
 induced, A, xi, 72; D, I, 
 397; E, 1034- 
 1037; E, 929; 
 F, 243; I, 470; 
 J, 764-767, 827. 
 by the earth's and 
 the sun's mag- 
 netism, A, xi, 72. 
 by other currents, 
 E, 1034; by 
 magnets, E, 
 1037. 
 
 intensity of, J, 703. 
 inversion of, by change of 
 
 liquid, E, 969. 
 laws of, G, 429; J, 730. 
 local, J, 694. 
 
 Electric currents, magnets act on, J, 
 
 737 ; N, 335. 
 
 magnetize, D, I. 381; I, 458; 
 J, 745; N, 306; see Elec- 
 tro magnetism, 
 measurement and detection 
 of, J, 696; see Electrome- 
 ter and Electroscope, 
 motions and sounds by, J> 
 
 630,749; N, 342. 
 mutual action of, D, I, 385; 
 E, 1015; E, 909; F, 
 243; N, 333. 
 paths and velocities of, E, 
 
 917. 
 rotation of magnet by, J, 
 
 763. 
 and solenoids, J, 742; N, 
 
 332. 
 
 secondary, G, 437. 
 terrestrial, J, 745. 
 thermo, A, vn, 62; G, 416; 
 
 J, 811, 815. 
 
 thermo, conditions for the 
 excitation of, F, 
 261. 
 
 excited when met- 
 als are plunged 
 into fused salts, 
 F, 263 ; by one 
 metal unequally 
 heated t F, 261; 
 by two metals, 
 F, 261. 
 
 unequal distribu- 
 tion of heat is 
 necessary in or- 
 der to excite, F, 
 261. 
 rotations produced 
 
 by, F, 262. 
 cut off, N, 343. 
 
 decomposition, see Electrolysis. 
 density, J, 620. 
 
 discharge, D, I, 302; E, 852,853; 
 F, 195; I, 409; J, 650, 
 663-667. 
 in air, F, 184. 
 
 from battery, effects of, F, 
 199. 
 
25 
 
 Electric discharge, calorific effects of, F, 
 
 188, 199. 
 
 chemical effects of, E, 961. 
 conductive, F, 191. 
 convective, F, 191. 
 . disruptive, D, 1, 302 ; F, 191. 
 effects of, E, 955, E, 
 854; J, 663, 707. 
 physiological, E, 
 
 956. 
 excites currents of air, F, 
 
 189. 
 experiments illustrating, F, 
 
 186, 198. 
 in gases, F, 190. 
 heat of the, F, 188, 224. 
 
 is inversely as 
 /X /\ fbe Conduct- 
 ing power 
 for equal 
 amounts of 
 I . electricity, D, 
 
 I, 301, 362. 
 
 inflammation of combusti- 
 bles by, E, 957. 
 in induction, E, 927. 
 lateral, D, i, 300; F, 203. 
 laws of induction, E, 
 
 928. 
 luminous in different media, 
 
 F, 190. 
 mechanical effects of, E, 
 
 960. 
 
 in rarefied air, F, 187. 
 spontaneous, F, 195. 
 striking distance for, D, I, 
 
 306. 
 
 varieties of, F, 191. 
 in vacuo, F, 184, 187, 204. 
 discharger, E, 950; E, 851; F, 187, 
 
 195, 197, 198; J, 651, 657. 
 distribution, J, 617-622. 
 eel, see Electric fishes, 
 egg, E, 951; E, 852; H, 226; I, 
 
 402; J, 665. 
 
 excitement, E, 932, 933, 938; F, 173. 
 figures, Lichtenberg's, J, 655. 
 fishes, A, vii, 57, xv, 539; D, i, 411, 
 412; E, 1046; E, 944; G, 391; 
 F, 263, et seq. ; I, 473 ; J, 830. 
 
 Electric fluid, non luminous, G, 387. 
 fluids, G, 403; N, 282, 283, 307. 
 fuse, J, 674. 
 glow, J, 665. 
 
 hail storm, Volta's, E, 940; E, 842. 
 hypotheses, see Electricity, theories of. 
 images, H, 382. 
 inclined plane, J, 647. 
 induction of, A, vn, 62, xi, 67-71; B, 
 375; D, I, 280, et seq.; 
 
 E, 927, 928, 1034; E, 
 828; F, 176-195; G, 
 377; 1,469; J, 62,3, 764; 
 K, 84, 104; N, 287, 334. 
 
 an action between contig- 
 uous particles, F, 177. 
 
 apparatus based upon, J, 
 776-804. 
 
 consequences of, F, 181, 
 192. 
 
 constant occurrence of in 
 electrical phenomena, F, 
 179. 
 
 by currents, E, 1034 ; I, 
 
 469. 
 galvanism, A, xi, 67. 
 
 influence of points and 
 terminal surfaces upon, 
 
 F, 180. 
 
 laws of, E, 928. 
 by magnetism, A, xi, 68. 
 in masses of metal by mov- 
 ing magnets, A, xi, 71. 
 in rarefied air, F, 187. 
 specific, D, I, 298 (table); 
 
 F, 177. 
 
 spread of, D, I, 289. 
 induetorium, J, 791, see Coil, 
 inductive capacity, D (table), I, 298, 
 . - F, 177; J., 626,627. 
 insects, F, 265. 
 
 insulation, A, vn, 60; D, I, 275; E, 
 911; E, 814; F, 170; I, 381; J, 
 532, 610. 
 
 intensity, A, vn, 63; D, I, 284; E, 
 
 968 ;F, 201; J, 703; K, 89. 
 
 versus quantity, E, 968; 
 
 F, 201. 
 
 jar, see .Ley den jar. 
 kite, A, x, 526; E, 963; F, 206. 
 
26 
 
 Electric lamp, Coulomb's, F, 181. 
 
 Duboscq's, E, 884. 
 obscure rays of, L, 276. 
 light, A, VII, 58; B, 398; D, I, 366; E, 
 951; E, 855; F, 174, 223; G, 
 410; J, 711-717; N, 302-305, 
 322. 
 cause of the, E, 951; K, 88; N, 
 
 304. 
 from coil, J, 794. 
 
 discharge, J, 664. 
 intensity of, J, 716. 
 pencil and star of, F, 186. 
 regulators of, E, 986; E, 884. 
 rotation of, around magnets, E, 
 
 936. 
 
 stratification of, E, 1041; J, 798. 
 machines, A, vil,60; B,381; D, I, 286; 
 
 E, 933-939; E, 834-841; 
 
 F, 181; G,378;H, 227; I, 
 388; J, 632-644; N, 289. 
 
 Cuthbertson's, E, 935. 
 
 cylinder, E, 933 ; F, 182. 
 
 Hare's, E, 935. 
 
 Holtz's, J, 636. 
 
 invention of the, F, 181. 
 
 Nairne's, J, 637. 
 
 management and care of, E, 
 936; E, 838; 1,390, 
 391. 
 
 plate, E, 935; F, 182; N, 
 290. 
 
 measure of the quantity of 
 electricity in, I, 391. 
 
 Ramsden's,*E, 935; J, 634. 
 
 theory of, E, 939. 
 
 Von Ebner's, J, 672. 
 
 hydro-, Armstrong's, E, 
 839; J, 638. 
 
 magneto, B, 475; D, I, 405; 
 E, 938; E, 1023; F, 
 260; J, 776-789 (Ladd's, 
 Clarke's, No 1 let's, 
 Holmes' s, S i e m e n ' s, 
 Wheatstone's, Wilde's 
 machines); K, 222; N, 
 335. 
 
 meteors, F, 209; 1,428. 
 multipliers, B, 541 ; F, 242, see Elec- 
 trometer, 
 nomenclature, E, 822 ; E, 905. 
 
 Electric organs of fishes, see Electric 
 
 fishes. 
 
 orrery, J, 647. 
 passive state of iron, J, 725. 
 pendulum, I, 378; J, 607. 
 piles (dry), J, 695. 
 pistol, B, 374; J, 671; plate, N, 
 
 296. 
 
 polarization, F, 174, 212; J, 626. 
 power of sealing wax, D, I, 273. 
 puppet, I, 401. 
 repulsion, see Electric attraction. 
 
 an effect of induction, F, 
 
 179. 
 
 residue, J, 655, 656. 
 shock, F, 195, 219, 254; G, 383; I, 
 
 397 ; N, 306, 323. 
 
 spark, A, vn, 68; E, 952, 953; E, 
 852; F, 174, 184,262; G, 388; 
 1,397; J, 644, 664; N, 303- 
 309. 
 
 from dry pile, A, vn, 68. 
 duration of, J, 675; N, 310. 
 from thermo-electric currents, 
 
 F, 262. 
 
 neutral point in, N, 309. 
 positive and negative, E, 953 ; 
 
 F, 184. 
 
 board, J, 676. 
 sparkling tube, N, 303. 
 spectrum, distribution of heat in the 
 
 L, 266. 
 due to invisible rays, L, 
 
 268. 
 
 extra violet rays of, L, 269. 
 low calorific power of the 
 
 blue end, L, 268. 
 most luminous part not the 
 
 hottest, L, 268. 
 maximum calorific effect 
 beyond the red ray, L, 268. 
 the red ray the hottest of 
 
 the visible rays, L, 268. 
 square, I, 403. 
 stool, E, 842; E, 940; G, 380; I, 
 
 399; J, 644. 
 
 telegraph, see Telegraph, 
 tension, E, 915; E, 817; F, 180, 
 
 226; 1,435; J, 636. 
 terms, definition of, E, 905. 
 theory of magnetism, N, 333. 
 
27 
 
 Electric thermo, series, J, 809 ; N, 200 ; 
 see Battery, thermo-electric and 
 Electricity, thermo. 
 units, British Association's, etc., J, 820. 
 unit jar, Harris, J, 660. 
 vacuum, F, 200; vane, J, 646. 
 wheel, E, 940; E, 842; I, 401; J, 
 
 646. 
 
 Electrical see Electric 
 Electricity, A, vn, 59; A, '62, 402, '66, 
 279, '67,287, '68,239; B, 
 368; D, 1,278; E, 773- 
 945; F, 169, 181; G, 369; 
 H, 231; I, 376; J, 2, 614; 
 K, 35, 83, 101. 
 action of points in dispers- 
 ing, D, i, 285. 
 
 animal, A, i, 587; B, 479, 
 482; D, i, 411; E, 
 1045; E, 944; 
 F, 264; G, 391; J, 
 829-832; K, 99. 
 experiments on, F, 
 
 265, 266. 
 Matteuci's researches, 
 
 F, 268. 
 
 origin of, F, 270. 
 uses of, F, 273. 
 Valli's experiments, 
 
 F, 268. 
 
 applied to medicine, J, 832. 
 apparent excitation of, by contact, F, 
 
 210. 
 apparatus for collecting and retaining, 
 
 A, vii, 62. 
 
 atmospheric, A, vn, 63, x, 526; B, 
 617 ;D, I, 313; E, 964; 
 
 E, 860, 861; F, 204; 
 G, 391 : I, 422 ; J, 851- 
 860; K, 87; N, 311. 
 
 'apparatus for detecting, 
 
 F, 204. 
 
 causes influencing, F, 205. 
 developed by che m i c a 1 
 decompo- 
 sition, A, 
 x, 527. 
 combustion, 
 A, x, 527. 
 evaporation, 
 A, x, 527. 
 
 Electricity, atmospheric, developed by 
 
 friction, A, X, 527. 
 collected by arrows and 
 
 kites, F", 206. 
 discovery of, B, 616. 
 origin of, A. x, 527 ; E, 
 
 1083 ; F, 206 ; N, 313. 
 phenomena of, E, 1083- 
 
 1093. 
 
 sources of, A, x, 527 ; E, 
 1083; F,206; N, 313. 
 variation of, F, 205. 
 from caoutchouc, K, 35. 
 chemical action of, F, 212; compare 
 
 Electrolysis, 
 of chemical action, A, vn, 64, ix, 21 ; 
 
 F, 212, 236; J, 680; N, 318,319. 
 clouds, J, 855. 
 
 condenser of, see Electric condenser. 
 
 conducting power of various metals 
 
 for, A, VII, 66 ; H, 142 ; D, I, 301, 
 
 361 (table); L, 224 (table); N, 321. 
 
 conducting power of various solutions 
 
 for, D, i, 365 (table) ; N, 
 
 321. 
 wires, mutual actions of, 
 
 D, I, 385, 
 
 conduction of, A, vn, 60; D, i, 299; 
 F, 243; J, 397, 817- 
 825, 608; L, 226. 
 influence of heat upon 
 the, L, 226; of 
 magnets, F, 243. 
 
 conductors of, A, vn, 66 ; D, i, 301, et 
 seq.; E, 910; E, 
 814; F, 170, 204; G, 
 273; I, 381; J, 397, 
 817-825; L, 224, et 
 seq.; N, 285, 339. 
 how they deport them- 
 selves between poles 
 of magnets, L, 47. 
 good, are also good con- 
 ductors of heat, L, 
 225. 
 
 connection b e't w e e n 
 them and insulators, 
 F, 204. 
 
 connection of life, nervous force and, 
 A, ix, 21; D, i, 307, 368; F, 273, 
 270. 
 
28 
 
 Electricity, current of, see Electric cur- 
 rents. 
 
 decomposition of salts by, see Electro- 
 lysis. 
 development of, A, vn, 69-63; E, 
 
 1043 ;E, 810-840; 
 
 F, 169; I, 377; G, 
 869. 
 
 by animals, see Ani- 
 mal electric ity. 
 
 blow pipe flame, K, 
 155. 
 
 chemical action, A, 
 Vii, 64, and ix, 
 21, 22; K, 210. 
 236. 
 
 cleavage, J, 618. 
 
 contact of dissimi- 
 lar metals, D, I, 
 323. 
 
 contact and pres- 
 sure, D, I, 323; 
 F, 174; J, 613. 
 
 in crystals, A, vn, 
 63, 64; D, I, 309; 
 F, 174; J, 614. 
 
 escape of steam, 
 A, VH, 62; B, 
 384; D, I, 310; 
 F, 185; E, 937; 
 H, 227. 
 
 friction, D, I, 273; 
 F, 169; J, 607, 
 612. 
 
 heat, D, I, 308, 407 ; 
 F, 261; com- 
 pare Electricity, 
 thermo. 
 
 magnetism, A, ix, 
 21, and xi, 67; 
 F 252. 
 
 movement of man, 
 A, vn, 61. 
 
 steam, see above, 
 escape of steam. 
 
 in tourmaline by 
 heat, D, i, 309; 
 F, 174. 
 
 by vegetables, E, 
 945; F, 173, 274. 
 
 Electricity, development of, difference 
 between quantity and tension, F, 
 180. 
 
 discharge of, see Electric discharge, 
 disguised, E, 941 ; E, 848 ; F, 192, 
 
 200; N, 288. 
 
 diurnal variation of, F, 205. 
 distribution of, E, 924; E, 825; J, 
 
 617; N, 294. 
 Dupay's theory of, see below, theories 
 
 of.' 
 dynamical, E, 862; J, 678. 
 
 changed into statical, A, 
 VII, 68, xi, 68; E, 
 933; F, 239. 
 the earth a reservoir of, E, 815 ; G, 
 
 376. 
 
 effects of, upon a conductor, G, 386. 
 the terminals, K, 90. 
 is equivalent in quantity to the amount 
 of chemical action by which it has 
 been developed, A, ix, 21. 
 how it exerts a magnetic force, G, 431. 
 is excited by 
 excitation of, by 
 evolution of, by 
 Franklin's theory of, see below, theo- 
 ries of. 
 
 free in the atmosphere, E, 964. 
 frictional, E, 809; J, 607-677; G, 
 
 407; N, 320,336. 
 frog current, F, 266, 270; J, 680. 
 and heat, K, 106; L, 224, 225. 
 heating po\re* of, G, pp, 212, 409; I, 
 
 417; J, 708; N, 301. 
 of human body, F, 270. 
 hypotheses of, see below, theories of. 
 galvanic, B, 402 ; F, 210, 263, 2&5. 
 
 conducting power of metals 
 
 for, F, 222. 
 
 discovery of, E, 965; F, 
 265; G, 398; N, 314. 
 how it differs from ordi- 
 nary, G, 30. 
 
 heating effects of, G, 408. 
 how excited, G, 401, 
 excitation of, by two fluids, 
 F, 218; by a single 
 pair, F, 211 ; by one 
 metal, F, 217. 
 
 see above, develop- 
 ment of by. 
 
29 
 
 Electricity, galvanic, intensity and 
 
 quantity of, E, 
 
 865; G, 408. 
 
 its origin, D, i, 315. 
 
 physiological effects 
 
 of, G, 411. 
 theory of, G, 402. 
 how exerted, see development of. 
 identity of all kinds of, D, I, 374, 378; 
 
 E, 1039; E, 939. 
 
 ignites alcohol, ether, etc., N, 301, 302. 
 
 metals, N, 323. 
 
 induction of, see Electric induction, 
 influence of, on the form of bodies, G, 
 
 376. 
 
 affinity, D, n, 1109. 
 initiates motion, K, 104. 
 
 other forces, K, 83. 
 insulated jars cannot be charged with, 
 
 F, 195. 
 
 insulation of, see Electric insulation, 
 insulating stool for, E, 940. 
 insulators of. A, vn, 60; D, I, 275 
 
 (table); E, 911; I, 381; see 
 
 Electric insulation, 
 intensity of, see below, quantity of. 
 iriversor of, F, 241. 
 kinds of, see below, two kinds of. 
 latent, E, 941. 
 law of, Poggendorff, J, 683. 
 and light, K, 107. 
 limitation of the term, K, 35. 
 a link among the other forces, K, 37. 
 loss of, E, 926; J, 621. 
 machine compared with that from 
 
 other sources, A, vn, 63, 68, xi, 
 
 68; F, 239. 
 magneto-, A, '64, 489; A, vn, 67; xi, 
 
 67; D, I, 397: E, 938; F, 252; J, 
 
 776. 781-790 ; G, pp. 437, 438. 
 of man, F, 270. 
 mechanical effects of, E, 857; F, 
 
 190; I, 420; N, 300. 
 molecular changes of conductors, K, 
 
 95. 
 
 muscular current of, D, I, 413. 
 non conductors of, F, 170; become 
 
 conductors by heating, F, 204. 
 organic, F, 263, 274. 
 physiological effects of, E, 854 ; F, 
 
 263 ; I, 415 ; J, 663, 707, 794 ; N, 306. 
 
 Electricity of plants, E, 045 ; F, 173 
 
 274. 
 positive and negative, G, 272; D, I, 
 
 278. 
 power of points in concentrating, E, 
 
 925; 1,384. 
 presence of free in the atmosphere, F, 
 
 204. 
 produced by, see above, developed 
 
 by- 
 
 proof plane for, D, i, 284; E, 922; 
 
 E, 823; J, 617. 
 
 quantity (and intensity) of, A, vn, 63, 
 66; E, 
 968; E, 
 F, 
 
 817 
 201 
 
 408 
 
 required in 
 electroly- 
 sis, D, i, 
 374; F, 
 239; G, 
 412, 
 relation of, to magnetism, D, i, 263; I, 
 
 451., 
 resides on surface, E, 923; E, 824; 
 
 G, 375; F, 175; I, 383; N, 294. 
 sources of, E, 1043 ; I, 377. 
 
 in the prime conductor, F f 
 
 183. 
 specific, D, ii (table), 1123. 
 
 induction (table), D, i, 297. 
 statical, A, vn, 63. 
 
 developed by friction, A, vn f 
 
 59, et seq. 
 heat, A, vn, 62, 
 
 64. 
 
 tests for, F, 269. 
 
 theories of, A, vii, 59, 69; D, I, 278; 
 E, 912; E, 816,863; 
 G, pp. 271, 403 ; I, 380 ; 
 J, 611; N, 284. 
 (Franklin's), D, i, 278; 
 E, 913; G, 271; J, 
 611; N, 284. 
 
 thermo-, A, vii, 62; xv, 426; B, 479; 
 D, i, 407; E, 941; E, 1044; F, 
 261 ; G, 416 ; H, 727 ; J, 808, et seq. ; 
 L, 14, 30-32, 265, 344. 
 
30 
 
 Electricity, two kinds of, D, i, 273 ; E, 
 813; E, 909; H, 231; I, 378; N, 
 283; G, 170. 
 of vegetables, F, 274. 
 velocity of, A, vii, 60; D, i, 304; E, 
 818; F, 197; G, 389; H, 231; J, 
 675; N, 310. 
 vitreous and resinous, D, I, 274 ; E, 
 
 909; H, 231. 
 
 voltaic, see Electric currents. 
 Electrifying, methods of, I, 382. 
 Electrics, idio, F, 170; J, 608. 
 Electro chemical decomposition, see 
 
 Electrolysis, 
 equivalence, K, 394. 
 order of the ele- 
 ments, D, i, 329. 
 theory, D, n, 1121. 
 
 Electrode, A, iv, 576; vn, 78; B, 437; 
 
 D, i, 369; E, 984; E, 882; F, 
 
 228; G, 413; H, 245; I, 435; J, 684. 
 
 polarization of, F, 230. 
 
 Electrodynamics, A, vn, 64; F, 240; 
 
 H, 248; J, 729-745. 
 Electrodynamic cylinder, F, 249; N, 
 
 311. 
 
 induction, F, 262. 
 laws, E, 902. 
 spiral, E, 1017; E, 910. 
 Electro-gilding, D, n, 1131; I, 440; J, 
 
 728. 
 
 Electrolysis, A, vn, 78; B, 433; D, i, 
 369; E, 990-992; E, 890; F, 
 227, 229, 233; H, 243; J, 722; N, 
 324. 
 
 of ammonium, F, 235. 
 apparatus for, F, 231. 
 
 and binary theory of salts, D, n, 
 1112. 
 
 chloride of copper, D, n, 1113. 
 is definite in amount and direction, D, 
 
 1,370; F, 229; K, 394. 
 equivalents, K, 373. 
 by frictional electricity, F, 236. 
 of fatty acids, D, in, 390. 
 
 fused compounds, F, 238. 
 laws of, D, 433 ; D, I, 369 ; E, 992. 
 of metals, F, 233. 
 order of the elements, D, I, 329. 
 of organic compounds, D, n, 1120, and 
 ill, 390. 
 
 Electrolysis of oxides, I, 444. 
 
 potash and soda, F, 234. 
 
 resistance of chemical affinity to, F, 
 238. 
 
 of salts, D, m, 390, n, 706, 1110; E, 
 993; E, 891; F, 232, 237, 239; I, 
 444;of sub salts, D, n, 1115. 
 
 secondary results of, D, n, 1117. 
 
 of silica, F, 232. 
 
 by single pairs of plates, F, 230. 
 
 of sulphate of soda, D, n, 1111. 
 
 theory of, B, 431; D, n, 1121; E, 
 1006; J, 721. 
 
 of water, E, 991 ; 1, 433. 
 Electrolytes, D, i, 369-379; n, 1114; 
 E, 882 ; F, 229, 230. 
 
 classes of, D, n, 1114. 
 
 composed of a conductor and non- 
 conductor, D, i, 373. 
 
 conducting nature of, F, 230. 
 
 decomposition of, F, 229. 
 
 must be compound bodies and liquid, 
 
 D, i, 369. 
 
 saline, table of, D, n, 1114. 
 Electro-magnetic action, see Electro- 
 magnetism, 
 clock, A, v, 369. 
 currents by revolving disc, F, 255. 
 
 motion of, E, 904. 
 discoveries, E, 1009-1014. 
 equivalence, K, 393. 
 induction, F, 252. 
 laws, D, i, 379; H, 256; E, 915. 
 locomotive, N, 344. 
 machines, A, vn, 69, 73, xi, 67 ; A, '64, 
 489; B, 475; D, I, 405; E, 938; 
 
 E, 1023; F, 255, 260; H, 269; I, 
 467; J, 781-790; K, 222; N, 335. 
 
 machines without iron, F, 255. 
 
 with alternating currents, F, 
 
 256. 
 
 single currents, F, 257. 
 permanent magnets, F, 
 
 258. 
 motions, D, I, 288, 403; E, 1023; E, 
 
 917. 
 
 motor, I, 467. 
 rotations, D, I, 388, 403. 
 Electro-magnetism, A, vii, 69 ; D, i, 
 
 384, 379; G, 429; H, 256. 
 Ampere's theory of, D, i, 384. 
 
Electro-magnetism, laws of, D, i, 379, 
 
 383; H, 256. 
 Electro-magnets, A, vn, 73; D, i, 
 
 381-383; E, 1021; E, 913, 915; 
 F, 249-256; G, 432; I, 459; J, 747; 
 N,. 332. 
 
 excitation of electricity by, F, 256. 
 how formed, D, i, 381. 
 
 how rendered most efficient, D, I, 383. 
 
 rotating, F, 250. 
 
 Electro-metallurgy, A, vii, 74 ; D, n, 
 1124; E, 994; G, 413; J, 726. 
 Compare Electro-gilding, Electro- 
 typing and Electro-plating. 
 
 as applied to the multiplication of 
 
 engravings, D, n, 1126 ; G, 415. 
 Electrometer, A, vn, 78; B, 441; D, i, 
 319; E, 1011; E, 820,905; F, 
 202; G, 381, 430; H, 269; I, 456; 
 J, 632, 697, 818; L, 15-32; N, 286, 
 327. Compare Electroscope. 
 
 astatic, D, I, 320: E, 882; F, 242; 
 N, 328. 
 
 calibration of the, L, 369, et seq. 
 
 -Cavallo's, E, 931. 
 
 coils, magnetism of, and means of 
 avoiding it, L, 34. 
 
 condensing, F, 202; I, 413. 
 
 construction of, L, 32. 
 
 Coulomb's, F, 172; N, 286. 
 
 differential, D, i, 360 ; J, 700. 
 
 Faraday's, J, 723. 
 
 frog, F, 269. 
 
 goldleaf, I, 395. 
 
 Henley's, J, 637. 
 
 Lane's, D, I, 296; J, 659. 
 
 marine, J, 700. 
 
 peculiarity of, in high deflections, L, 
 342. 
 
 quadrant, D, I, 291. 
 
 simple, N, 327. 
 
 silver, J, 723. 
 
 tangent, D, I, 379; E, 1012. 
 
 torsion, E, 919. 
 
 Thomson's, J, 662, 700. 
 
 Volta's, E, 931. 
 
 Electro-motive force, D, i, 327, 357; 
 G,401; J,683, 
 703, 826. 
 of elements, J, 
 
 Electro -motive force, measurement of, 
 
 D, i, 357. 
 
 Electromotive series, J, 681. 
 Electromotors, F, 213. 
 Electrophorus, A, vii, 79; B, 380; D, 
 i, 288; E, 932; E, 833; F, 179; 
 G, 380; H, 270; I, 393; J, 632; N, 
 291. 
 
 Electro-plating, I, 448; N, 325. Com- 
 pare Electro-metallurgy, 
 use of bisulphide of carbon in, D, n, 
 
 1130. 
 
 Electro-positive and Electro-negative 
 
 elements, D, I, 329; E, 970; E, 
 
 867; F, 229, (table) 211; J, 719. 
 
 Electroscope, A, vii, 78; B, 404; D, i, 
 
 276, 326; E, 909; E, 820, 846; 
 
 F, 171, 204; G, 381; H, 270; I, 378; 
 
 J, 607, 700. Compare Electrometer. 
 
 Bennett's gold leaf, D, i, 276 ; E, 931 ; 
 
 J, 631. 
 Bohnenberger's, E, 979; E, 873; J, 
 
 695. 
 condensing, E, 931, 944; F, 102; I, 
 
 413; J, 661. 
 gold leaf, D, I, 326; E, 846; I, 395; 
 
 J, 630; N, 286. 
 Henley's, E, 940. 
 quadrant, J, 637 ; N, 291. 
 Electrostatics, J, 729; laws of, F, 
 
 181. 
 
 Electro-thermometer, J, 709, 816. 
 Electrotype, compare Electro-metal- 
 lurgy; A, vii, 74; B, 425; D, II, 
 1124; E, 994; E, 892; F, 210; 
 G, 413; H, 271; 1,445; N, 326. 
 moulds, D, n, 1126. 
 Electrovection, D, n, 1116. 
 Electro-zincing, D, n, 1128. 
 Elements, chemical, A, vn, 79; C, 3; 
 1), i, 1, n, 435; E, 7; E, 1; G, 
 11. 
 
 bad absorbers and radiators, L, 365. 
 distinction between metullic and non- 
 metallic, D, i, 2, and n, 435. 
 negative, in chemistry, A, vn, 65; 
 
 of a pile, A, vn, 64; E, 982. 
 table of, F, 211. 
 Eliquation, A, vn, 91. 
 Emery, D, n, 818. 
 Emission theory of heat, see Heat. 
 
32 
 
 Endosmose and exosmose, A, vn, 147, 
 xvi, 729; D, I, 71, n, 1116; E, 
 300-306; E, 244-251; F, 63; J, 
 103; N,142; G, 146; see Osmose. 
 Endosmometer, E, 245; J, 103. 
 Endosmotic currents, direction of, E, 
 
 302. 
 
 equivalents, J, 104. 
 
 Energies of the solar system, L, 438. 
 Energy, J, 38 ; L, 150. Compare Force, 
 actual, L, 161. 
 conservation of, J, 40. 
 convertibility of dynamic and poten- 
 tial, L, 152. 
 
 dynamic or actual, defined, L, 151. 
 mechanical, converted into heat, L, 21. 
 extricable from coal, A, 
 
 ix, 23. 
 
 of motors, A, xi, 326. 
 muscular, how excited, G, 87. 
 potential or possible, J, 39; L, 161, 
 
 162, 162. 
 
 of solar system, L, 438. 
 all terrestrial, due to sun, L,466,< stq. 
 Engine, see Steam (etc.) engine. 
 Eolian harp, A, I, 149; M, 123. 
 Eolipile, A, I, 160; E, 674; H, 14; J, 
 
 393. 
 
 De Garay's, E, 675. 
 Epipolic dispersion, see Fluorescence. 
 Equality of moments, A, xi, 327. 
 
 pressure, B, 76. 
 Equator, magnetic, J, 590. 
 Equatorial current, Europe overflowed 
 
 by, L, 188. 
 
 magnetic position, D, I, 416. 
 ocean winds and moisture of European 
 
 climates, L, 188, 189. 
 Equidiffusive liquids, existence of 
 
 groups, D, I, 69. 
 
 Equilibrium, A, xi, 321; B, 65; C, 34; 
 E, 105; E, 38; F, 70; G, pp. 
 46, 92; I, 46; J, 9. 
 conditions of, F, 70. 
 definition of mechanical, C, 34. 
 different kinds of, I, 46. 
 of floating bodies, C, 242; E, 258; 
 
 J, 87. 
 
 fluids, see below, of liquids, 
 forces, B, 43; J, 18. 
 heavy bodies, I, 44 ; J, 44. 
 
 Equilibrium, indifferent, B, 65; G, 48; 
 
 N, 39. 
 of lever, E, 199; E, 114. 
 
 liquids, B, 83; C, 228; E, 201, 
 
 202; F, 111; J, 76-79. 
 free from gravity, E, 200. 
 between laminae, E, 294; 
 
 E, 240. 
 
 of different densities, F, 111. 
 in communicating vessels, 
 
 F, 111. 
 machines, E, 192. 
 
 solids immersed in fluids, F, 112. 
 
 supported on an axis, E, 147. 
 a horizontal sur- 
 face, E, 148. 
 points, E, 150. 
 
 stable, neutral and unstable, C, 62; E, 
 
 207; G,48; J,45; N,39,40; B, 65. 
 
 of temperature (mobile), D, I, 187; J, 
 
 330. 
 
 Equinoctial storm, G, 291. 
 Equivalent, meaning of the term, K, 
 
 329. * 
 
 mechanical, of heat, see Heat, 
 proportions, law of, D, I, 14. 
 Equivalents, chemical, A, v, 39, 41; 
 VII, 259; B, 
 431 ;D, 1, 19, 
 II, 1153, tt 
 teq. 
 
 of elements, 
 data for fix- 
 ing, D, n, 
 1153, et seq. 
 deduced from 
 specific 
 heats, J, 374. 
 
 table of, D, i, 17, n, 1161. 
 Eriometer, A, VH, 272; H, 290. 
 Escapement, B, 173; J, 69. 
 Ether, hypothetical interstellar, A, i, 
 159, x, 518; F, 
 275, 276; J, 342, 
 414 ;K, 123, 133, 
 242, 271, 347; 
 L, 264, 300, 307, 
 355. 
 
 fills all space and 
 penetrates a 1 1 
 bodies, L, 307. 
 
33 
 
 Hither, hypothetical, fills all space and 
 petietrates all bod- 
 ies, L, 307. 
 
 mode of transmis- 
 sion of heat by, 
 L, 300. 
 
 objections to, K, 133. 
 
 oscillations of, F, 
 
 I 
 
 275. 
 
 the power of impart- 
 ing motion to, and 
 accepting motion 
 from, are propor- 
 tional, L, 355. 
 propagates heat and 
 
 light, L, 264. 
 waves of, F, 276. 
 Ethereal medium, see Ether. 
 Eudiometer, A, vn, 319; D, n, 467, 
 
 468. 
 Europe, cause of mildness of climate of, 
 
 L, 194. 
 
 the condenser of the Atlantic, L, 194. 
 Eustachian tube, use of, M, 74, 85. 
 Evaporation, A, vir, 344, xv, 44; B, 
 530; D, 1,240-244; G, 238; H, 292; 
 N, 210. 
 acceleration of, G, 239; E, 625; E, 
 
 673; I, 228; J, 280. 
 electricity of, D, i, 309; F, 210. 
 from surface only, D, i, 244. 
 frigorific effects of, A, ix, 434; B, 534; 
 D, 1,244; E, 636; E, 681; J, 
 288; L, 168, 169; N, 210. 
 goes on at all temperatures, N, 210. 
 influence of pressure upon, D, i, 244 ; 
 
 I, 224, 226. 
 instantaneous in vacuum, see below, 
 
 in vacuo. 
 limit of, D, i, 243. 
 mechanical force of, E, 639; E, 
 
 684. 
 
 meteorological importance of, D, i, 246. 
 opposed by capillarity, F, 61. 
 rate of (table), D, I, 245, 249. 
 in vacuo, D, i, 246 ; F, 372 ; I, 226. 
 water frozen by, L, 169. 
 Exchanges, theory of, J, 330; L, 274. 
 Exhausting syringe, D, i, 37; see Air 
 pump. 
 
 Exhaustion of gases, J, 152, 153 ; N, 
 
 156. 
 
 Exosmose, see Endosmose and Osmose. 
 Expansibility and Compressibility, E, 
 
 23,550; 1,19; N, 19. 
 Expansion, A, vn, 373, ix, 16, xv, 
 
 428; B, 485; C, 496-528, 431; D, I, 
 
 165-175; E, 23, 530, et seq.; E. 
 
 22, 610; F, 360; G, 16; H, 294; I, 
 
 19; J, 228-260; K, 54; L, 74; N, 19. 
 of alcohol by heat, C, 518; L, 91. 
 
 alloys in solidifying, C, 553. 
 apparent and absolute, C, 515; E, 
 
 538; E, 598. 
 applications, C, 504; E, 532; I, 212; 
 
 J, 244. 
 of bismuth in cooling, L, 95. 
 
 brass by heat, L, 97, et seq. 
 
 Britannia bridge, C, 503. 
 coefficients of, C, 491-496; E, 591; 
 
 H, 295; J, 239; L, 81, 104. 
 of crystals, E 526; E, 590; J/243; 
 
 L, 100. 
 cubical, B, 490; C, 431, 492; E, 524; 
 
 L, 104. 
 curves of the, of liquids, E, 541 ; E, 
 
 602. 
 
 effected without chilling, L, 88 
 of fluids by heat, B, 492; F, 361-371. 
 force of, A, ix, 16; C, 499; E, 530; 
 
 E, 593 ; J, 244, 267. 
 of ice, J, 267. 
 
 formula for, C, 515, 518; J, 244. 
 
 of gases, B, 493; C, 528; D, 1,169; 
 E, 547; E, 253, 605- 
 607; J, 111, 228,253-256; 
 L, 79. 
 without chilling, L, 88. 
 
 of glass, A, xv, 429; C, 497, 498. 
 
 heat absorbed, C, 475, 480; L, 29. 
 
 by heat, compare Heat, A, ix, 16; C, 
 491, 430; D, I, 169, 175; 
 
 F, 360; G, 228; N, 199; L, 
 79. 
 
 progi'essive ratio of, A, vit, 
 374, IX, 16; D, I, 174, 
 (table) 175; E, 529; E, 
 592 ; K, 54. 
 
 inequality of, K, 54. 
 
 of iron by heat, L, 97, et seq. 
 
34 
 
 Expansion, Kopp's determination of, L, 
 
 105. 
 
 Lavoisier's method of finding, J, 239. 
 of lead, anomalous, D, 1, 165; L, 99. 
 linear, C, 431, 491, 494; L, 104. 
 of liquids, A, vii, 374, IX, 16; C, 507, 
 516-519; D, 166; E, 
 536; E, 597, 602; H, 
 296; I, 214; J, 247; L, 91. 
 above the boiling point, C, 
 
 519. 
 absolute and apparent, C, 
 
 507. 
 change of rate with change 
 
 of temperature, C, 517. 
 curve of the, C, 518; E, 
 
 541. 
 experiments upon, C, 516, 
 
 519. 
 
 formula for alcohol, ether 
 and oil of turpentine, C, 
 518. 
 
 by heat, see above, D, i, 166. 
 laws of, I, 214. 
 
 mercury, A, xv, 428; C, 508-515; 
 D,i, 176 ;E, 540; E, 
 598-600; J, 248. 
 absolute, determination of, 
 C, 508, 509 ; formula 
 for, C, 609. 
 
 apparent, determination 
 of, C, 513; formula for, 
 
 C, 513, 614. 
 apparent and absolute, C, 
 
 615. 
 
 coefficient of, C, 510. 
 correction of barometer 
 
 for, C, 508. 
 at different temperatures, 
 
 D, i, 175. 
 
 empirical formula for, C, 
 
 610, 511. 
 
 rates of, A, xv, 428. 
 metals, D, i, 166 (table), and in, 
 
 767. 
 
 at moment of solidification, E, 87. 
 phenomena produced by, E, 531. 
 rate of, of various bodies, by heat, A, 
 vn, 374; of gases, E, 547. 
 more rapid near melting or 
 vaporizing points, A, ix, 16. 
 
 Expansion of solids by heat, A, ix, 16 
 
 B, 489; C, 494- 
 497; D, i, 165; E, 
 522-528; E, 
 589-591, 595; J, 
 239; 1,210; L, 73, 
 96, 104. 
 
 of solids by heat, applications of the, 
 
 C, 604; 1,212. 
 determination of cu- 
 bic, B. 489; C, 
 495, 515; linear, 
 C, 494. 
 
 experiments upon, 
 
 C, 494, 496; 
 
 formulae for, C, 
 
 516. 
 
 illustrations of, C, 
 
 500. 
 
 order of, and of com- 
 pressibility, C , 
 497. 
 related to fusibility, 
 
 C, 497. 
 table of the, E, 
 
 528. 
 
 variation with tem- 
 perature, C, 497. 
 superficial, coefficient of, L, 104. 
 uniformity of, in solids, E, 527. 
 varying of fluids, F, 365. 
 of volume, L, 74. 
 
 of water, A, vn, 374, and ix, 433; C, 
 620-527; E, 542; L, 92-94. 
 coefficient of, C, 527. 
 curve of, C, 521, 524. 
 empirical formula for, C, 626, 
 
 527. 
 
 experiments upon, C, 523. 
 in freezing, A, ix, 433 ; L, 98, 
 use in nature, L, 
 
 94. 
 
 by heat and by cold, L, 92. 
 without performing work, L, 88. 
 
 refrigeration, L, 89. 
 Experiment, Berthollet's, J, 139. 
 Florentine, J, 70. 
 Foucault's, J, 714. 
 Franklin's J, 284. 
 Fresnel's, J, 542. 
 Galvani's, J, 678. 
 
35 
 
 Experiment, Grimaldi's, J, 542. 
 
 Henry's, J, 775. 
 
 Ingenhouse's, J, 319. 
 
 Leidenfrost's, J, 303. 
 
 Maskelyne's, J, 42. 
 
 Matteuci's, J, 767. 
 
 (Ersted's, J, 696. 
 
 Pascal'?, J, 116. 
 
 Peltier's, J, 816. 
 
 Sulzar's, N, 314. 
 
 Torricelli's, J, 115. 
 Experiments, Boutigny's, J, 303. 
 
 Chladni's, J, 216. 
 
 Colladon & Sturm's, J, 180. 
 
 Delarive's, J, 801. 
 
 Despretz's, E, 275; J, 320. 
 
 Hallstrom's, J, 253. 
 
 Hope's, J, 252. 
 
 Latour's, J, 285. 
 
 Lissajous', J, 217-222. 
 
 Pascal's, E, 194, 262; J, 116. 
 
 Plateau's, E, 200. 
 
 Eegnault's, E, , 276 ; J, 256-273, 370. 
 Explosion, A, vn, 374. 
 
 in coal mines, L, 251. 
 
 at Erith, M, 23. 
 
 of steam boilers, A, xv, 60; D, I, 281; 
 
 E, 671; E, 701; 
 
 G, 258; L, 127, 178. 
 
 possibly due to the 
 
 spheroidal state, D, 
 
 1,261,281; L, 178. 
 
 Extension, C, 10, 11; E, 13; F, 50, 
 
 52; J, 3, 4; N, 15. 
 
 Eye, A, vir, 380; B, 297-304, 307; E, 
 779-781; E, 468, 469, 480; F, 
 354-356; G, 347; H, 298; J, 512- 
 515,524; N, 245-247. 
 
 absence of spherical aberration, F, 
 355. 
 
 achromatism of, B, 304; F, 355. 
 
 action of, upon light, E, 780; F, 355. 
 
 adaptation of, to different distances, 
 B, 299; E, 790; F, 356; G, 354. 
 
 cause of far-sightedness, see Long- 
 sight. 
 
 choroid coat of, F, 354. 
 
 composite structure of, B, 297. 
 
 duration of impressions on the retina, 
 F, 356. 
 
 glass, J, 485, 528. 
 
 Eye, insensibility of, to certain colors, F, 
 
 357. 
 inversion of images formed in, E, 
 
 781. 
 how it judges of size and distance, 
 
 see above, adaptation of. 
 not perfectly achromatic, F, 355. 
 a lens, J, 490 ; how moved, G, 348. 
 as an optical instrument, F, 354 ; op- 
 tic axis of, G, 353. 
 a polariscope, E, 562. 
 structure of the human, E, 779; F, 
 
 354; G, 348: H, 298, I, 350; in 
 
 lower animals, F, 355. 
 pieces, A, xi, 475; E, 809; E, 500, 
 
 512; H, 305; J, 483, 485, 489. 
 vision with both, B, 307. 
 
 Factors for dew point (Glaisher's), J, 315. 
 Falling bodies, action and reaction of, 
 
 E, 77. 
 action of gravity upon, 
 
 G, 55. 
 application of laws of, 
 
 E, 158. 
 
 descent of, in curves, E, 
 
 160;G, 55. 
 
 upon inclined 
 
 planes, E, 
 
 159. 
 
 deviation of, N, 90. 
 experiments on, N, 84. 
 highest velocity of, K, 
 
 337. 
 on inclined planes, E, 
 
 159. 
 
 laws of, A, xi, 321 ; E, 
 71;I,53;G, 
 55; J, 50; N, 
 84. 
 
 ( table \E, 156. 
 phenomena of, K, 318. 
 retarded by air, A, xi, 
 
 322; G, 54. 
 
 spaces described by, A, 
 XI, 322; E, 153; E, 
 71; F, 82; formula 
 for spaces described, 
 
 F, 83. 
 
 uniformly accelerated, 
 N, 83. 
 
36 
 
 Falling bodies, velocity of, E, 152; G, 
 
 54; N, 87. 
 
 verification of the laws 
 of, K, 
 157. 
 
 third law 
 
 of, 1, 56. 
 
 Whole space described 
 
 by, K, 154. 
 force, see Force. 
 
 stars, A, xi, 413; B, 614. See Mete- 
 or.*. 
 
 Faraday's nomenclature, E, 882. 
 Far-sightedness, see Long-sight. 
 Fata Morgana, A, vii, 426; H, 305, 308. 
 Fatigue of metals, A, xv, 138. 
 Faults in mineral veins, I), n, 678. 
 Feather, attracts the earth, G, 32. 
 Field glass, J, 489. 
 
 of view, J, 490. 
 Figure, see Form. 
 Figures of Lichtenberg, F, 200. 
 Films, iridescence of, A, v, 499. 
 Filter, A, vii. 501. 
 Filtration, G, 19. 
 Finder, J, 492. 
 Fire an action, not nn element, D, I, 1; 
 
 G, 209. 
 alarm telegraphic, A, xv, 343; E, 
 
 928. 
 
 nnnihilator, A, vii, 615. 
 balls, see Meteors, 
 balloon, L, 80. 
 clny, D, n, 827. 
 
 engine, A, vii, 516; B, 141; E, 376; 
 E, 294; G, 183; I, 144; J, 163; 
 N, 173. See Steam, 
 places, draught, J, 402. 
 proofing, A, vii, 522. 
 open, E, 701. 
 produced by friction, L, 22. 
 regulators, E, 594. 
 screens, action of glass, L, 319. 
 syringe, ignition of bisulphide of car- 
 bon vapor in, L, pp. 43, 71. 
 works, J, 168. 
 Fishes rie in the water, N, 132. See 
 
 Electric fishes. 
 
 structure of the body of, G, 154. 
 swimming bladder of, J, 89. 
 Fizeau's experiment, J, 422. 
 
 Flame, compare Blow pipe, A, vii, 545 
 
 x, 574; D, II, 636; J, 400; G, 209. 
 
 action of, upon an electrified body, D, 
 
 I, 307. 
 
 sound on naked, M, 230, 253. 
 candle and gas, L, 59. 
 cannot pass wire gauze, why, L, 250. 
 cause of its luminosity, D, II, 638. 
 cooling effect of tubes and wire gauze 
 
 on, D, n, 635. 
 
 constitution of, D, II, 636, 638; L, 59. 
 Davy's investigation of, L, 59. 
 effect of unisonant notes on singing, 
 
 M, 229. 
 
 an exceedingly delicate acoustic rea- 
 gent, M, 239. 
 
 experiments on tall, M, 236. 
 harmonic notes of, D, n, 635. 
 high temperature of, D, n, 635. 
 influence of pitch on, M, 239. 
 
 surrounding tubes on, M, 
 
 219, 252. 
 
 rythmic friction of, M, 217, 252, 
 Schaffgotsch's experiments on, L, 292. 
 shortening and lengthening of, M, 237 
 singing, L, 261, 284; M, 221, 252. 
 analysis of, M, 223. 
 Faraday's experiments on, L, 
 
 384. 
 
 structure of, D, n, 638; L, 59. 
 Flames, sounding, M, 217; 252. 
 voltaic effects of, D, I, 366. 
 vowel, M, 241. 
 Flats and sharps, E, 455. 
 Flexibility, F, 52; G, 26. 
 Flexure of beams, E, 162. 
 Flies, how walk upon ceilings, G, 176. 
 Flight of birds, N, 33; see also Reports 
 of the .Eronautical Society for 1868 
 and '69 in "Engineering": Tran>- 
 actionsof the Linn*Ean Society and 
 the " Reign of Law," by the Duke 
 of Argyle. 
 
 Floating bodies, B, 93; E, 206; I, 93. 
 attraction and repul- 
 sion of, E, 296 ; F, 
 62. 
 
 equilibrium of, A, ix, 
 414; E, 258; E, 
 207. 
 laws of, C, 241 ; G, 138. 
 
 
37 
 
 Floating bodies, stability of, N, 131. 
 current, E, 909. 
 docks, E, 206. 
 Flotation, principles of, I, 93. 
 
 illustrated, I, 94. 
 
 Flow from, capillary tubes, E, 243. 
 of liquids, E, 218. 
 
 solids under pressure, A, '66, 700. 
 theoretical and actual, E, 216. 
 Fluid,-!, 2; G, 24. 
 
 currents, general property of, F, 130. 
 elastic, J, 110. 
 
 equilibrium law of, B, 76; F, 106. 
 imponderable, J, 3. 
 pressure, formulae for, B, 84; F, 108. 
 law of, and its consequences, 
 
 F, 108. 
 
 law of equality, F, 105. 
 varies with depth, F 107. 
 Fluidity, C, 215; F, 51; J, 3. 
 Fluids, E, 186. 
 
 are bad conductors of heat, F, 366. 
 compressibility of, A, vn, 50; F, 105. 
 elastic, general properties of, F, 121. 
 
 and non elastic, E, 235; F, 
 
 104. 
 
 elasticity of, F, 104. 
 equality of pressure of, F, 105. 
 expansion of, during vaporization, B, 
 
 492; F, 371. 
 
 flow of, from vessels, F, 129. 
 friction in, F, 132. 
 general properties of, F, 129. 
 lateral pressure of, F, 109, 129. 
 in motion, phenomena of, F, 129. 
 properties of, F, 104. 
 pressure of, B, 84; F, 106. 
 resistance of, E, 230; E, 143. 
 upward pressure of, F, 108, 129. 
 velocity of, ratio between diameter of 
 
 channels and, F, 131. 
 velocity of, in nai'row channels, F, 131. 
 Fluorescence, A, vii, 575 ; 1), i, 137, 
 138; E, 846; E, 533; F, 302; 
 J, 478. 
 
 of sulphate of quinine in the extra- 
 violet spectrum, L, 369. 
 Flute, tones of the, M, 195. 
 Fluxes, J, 264. 
 
 Fly-wheel, A, vii, 681, xv, 52; B, 
 511; C, 623; G, 17; N, 67. 
 
 Focal distance, J, 333. 
 Foci, G, 322; J, 183. See 
 
 Mirrors. 
 
 Focus of parallel rays, N, 229. 
 real, J, 433, 442. 
 vertical, J, 432, 444. 
 Fog, A, vn, 583; E, 1067; E, 974; 
 
 G, 273 ;'H, 307; J, 837. 
 bows, E, 841; E, 537. 
 Foot pound, A, ix, 21; xi, 326; E, 
 
 711; J, 38,395. 
 explanation of, L, 54. 
 a measure of heat, E, 
 
 759. 
 
 Force, compare Energy, A. xi, 319 ; B, 
 44; E, 35; G, 21; J, 2, 9; N, 21. 
 accumulation of, G, 87, 
 animal, derived from food, K, 432. 
 application of, G, 87. 
 centrifugal and centripetal, see Cen- 
 trifugal and Centripetal Force, 
 change of point of application, C, 38. 
 chemical, see Chemical affinity, 
 coercive, E, 881 ; J, 581. 
 conservation^, A, ix, 20, 21 ; J, 40. 
 Faraday's thoughts on 
 
 the, K, 359. 
 steam engine illus- 
 trates, L, 132. 
 importance of the the- 
 ory, K, 356. 
 contractile, J, 245. 
 
 convertible, all kinds of, are, A, ix, 21. 
 definite quantity of, D, i. 424. 
 definition of mechanical, C. 32. 
 
 the term, G, 21; E, 29; 
 K, 19,335,379,330; N, 
 21. 
 
 developed by evaporation, E, 684. 
 direction of, E, 40; J, 14. 
 of expansion, B, 118; E, 593, 603; 
 
 J, 244, 267. 
 of gases, J, 244. 
 falling, K, 253, 343. 
 of Gravity, see Gravity. 
 Grove's definition of the term, K, 19. 
 of heat in expanding bodies, L, 98. 
 and heat, relations of, E, 758 ; K, 262. 
 imparted to machines, K, 218. 
 importance of new views of, K, p. 
 XXX. 
 
88 
 
 Force, impulsive, J, 36 ; N, 25. 
 
 indestructibility of, A, ix, 21; K, p. 
 XII. 
 
 intensity and quantity of, C, 37, 53. 
 
 internal, see Force, molecular. 
 
 laws governing direction of, C, 32. 
 
 lecture on, by Tyndall, L, 450. 
 
 lines of magnetic, F, 153. 
 
 living, C, 52. 
 
 and dead, K, 333. 
 
 of machines partially lost as heat, in 
 overcpming friction, L, 21. 
 
 of matter in motion,^, 27. 
 
 measure of, C, 34 ; formula for, C, 36. 
 
 mechanical, of our system may be- 
 come exhausted, L, 443. 
 
 mechanical, time is required to trans- 
 mit, A, i, 75. 
 
 molecular, F, 51; G, 22; J, 1, 60, 
 is irresistible, L, 93. 
 magnitude of, L, 153. 
 power of, L, 154. 
 
 calculable, L, 159. 
 Tyndall on, A, '68, 102. 
 
 moments of, A, xi, 320; J, 22. 
 
 moving, see Momentum. 
 
 monogenesis of, A, ix, 21. 
 
 origin of the idea of, C, 6; G, 21. 
 
 persistence of, A, ix, 21, xi, 325; K, 
 XXXIX. 
 
 power or quantity of a, formula for, 
 C, 53. 
 
 produced by water power, K, 315. 
 
 projectile, formula for, E, 129. 
 
 resolution of, A, xi, 320. 
 
 synonymous with volition, C, 7. 
 
 transformation of, D, I, 426. 
 
 transmission of, by machines, A, xi, 
 326. 
 
 unit of, A, XI, 319; C, 36, 93; E, 37. 
 
 use of the doctrines, K, XIII. 
 
 value of, A, xi, 319. 
 
 varieties of, E, 30. 
 
 vital, supposed conservative action of 
 vital, L, 230. 
 
 what is it, K, 251. 
 Forces, central, A, iv, 652 ; E, 54. 
 
 analysis, E, 176; E, 
 54. 
 
 centrifugal and centripetal, see Cen- 
 trifugal, etc. 
 
 Forces, components of, A, xi, 319; J, 
 
 15; N, 28. 
 
 composition of, A, xi, 319; B, 43; C, 
 38,42; E, 109; F, 
 75; N, 28. 
 parallel, C, 43, 47. 
 practical examples of, 1, 28. 
 connection and equivalence of the 
 
 (Liebig's essay upon), K, 387. 
 constant, A, xi, 319. 
 convertibility of, A, ix, 20. 
 correlation of, A, ix, 21 ; E, 758. 
 the physical, K, passim. 
 
 meaning of 
 the phrase, 
 K, 3, 383. 
 
 correlation of the physical, the prob- 
 lem to be 
 solved, K, 
 189. 
 
 difficulties of 
 the investi- 
 gation, K, 
 194. 
 
 and vital 
 (Carpen- 
 ter's es- 
 say), K, 
 401, and K, 
 XXXII. 
 decomposition of, C, 40; formulae for, 
 
 C,41. 
 
 are definite quantities, E, 36. 
 distinctive characteristics of, I, 25. 
 electromotive, see Electrometers, 
 equilibrium of, A, xi, 319; I, 30. 
 examples of action of, F, 76. 
 the great, of nature, G, 21. 
 illustration of parallel, C, 46. 
 incessant or continued, A, xi, 319. 
 impulsive, A, xi, 319; J, 36; N, 25. 
 of inorganic nature (Mayer's essay), 
 
 K, 251. 
 interaction of natural (Helmholtz's 
 
 essay), K, 211. 
 measure of, E, 41. 
 mechanical, A, xi, 317. 
 molecular, C, 117, 342; D, I, 33; F, 51; 
 
 1,64. 
 
 energy of, C, 349, 351, 352; 
 L, 93, 153. 
 
Forces molecular, two classes of, C, 117. 
 mutual relations of different kinds, D, 
 
 I, 427. 
 not parallel,' applied at different points, 
 
 E, 49. 
 parallel, J, 20; formula for, C, 45; 
 
 centre of, J, 20. 
 
 parallelogram of, A, xi, 319 ;'B, 44; 
 C, 39; E, 108; E,45; F, 75; I, 
 27; J, 15; N, 30; formula for, C, 
 40. 
 
 passive or resisting, A, xi, 319. 
 physical, A, '64. 674. 
 polar, heat required to overcome, L, 
 
 160. 
 
 polygon of, J, 19. 
 powers and resistances, I, 24. 
 propositions in regard to, E, 42. 
 regulation of, N, 66. 
 representation of, C, 38; J, 14; N, 28, 
 
 29. 
 resolution of, A, xi, 319; E, 110; E, 
 
 50; F, 75; N, 28. 
 practical examples of, I, 
 
 29. 
 resultant of parallel, A, xi, 319; C, 39; 
 
 E, 112; I, 29. 
 and component, I, 26. 
 of various, N, 28-31. 
 statical, E, 106; E, 39. 
 system of, E, 107 ; E, 44. 
 transfer of, E, 123 ; E, 123. 
 triangle of, A, xi, 320; J, 19. 
 variable, A, xi, 319. 
 vital, inter-relation of, with the physi- 
 cal forces, A, ix, 21. 
 Forcing pump, see Pumps. 
 Form, F, 50. 
 
 of bodies dependent on heat, G, 228. 
 of crystals, see Crystalline form. 
 Foucault's apparatus, E, 404; J, 419. 
 
 experiment, J, 714. 
 Fountain at Giggleswick, J, 159. 
 
 Hiero's, E, 377 ; F, 136 ; I, 135 ; J, 156. 
 intermittent, E, 363; I, 137; J, 156; 
 
 N, 174. 
 
 in vacuo, J, 155. 
 Fountains, I, 88; N, 174. 
 artificial, I, 135; G, 135. 
 intermittent, E, 363; I, 137. 
 theoretical action of, F, 131. 
 
 Franklin's kite, E, 860; plate, N, 
 
 296, 297; pulse glass, E, 677. 
 Fraunhofer's bands, F, 303 ; curve, F, 
 
 304. 
 lines, A, xn, 539; E, 461; H, 312; 
 
 J, 471, 472. 
 cause of, L, 429. 
 refractive indices of, F, 303. 
 Freezing, F, 371; H, 314; J, 265. 
 apparatus, J, 288-291. 
 effect of, on water pipes, L, 94. 
 of mercury in hot crucibles, D, I, 262; 
 
 E, 699; L, 179. 
 by solid carbonic acid, L, 
 
 in. 
 
 mixtures, A, vn, 741; C, 556; D, i, 
 218; E, 610; E, 657; I, 223; J, 
 268; N, 208; G, 245. 
 planes of, in ice how recognized, L, 
 
 324. 
 point, C, 548; E, 569. 
 
 lowered by pressure, A, ix, 21 ; 
 
 L, 148. 
 of thermometers, L, 106. 
 
 water, effect of salt on, C, 
 
 549. 
 in red hot vessels, E, 668; D, I, 262; 
 
 F, 372; L, 179. 
 
 together of pieces of ice, L, 147. 
 in vacuo, F, 372. 
 of water, A, ix, 433; C, 549; E, 
 
 618; H, 314. 
 bursts iron bottle, L, 93. 
 by its own evaporation, B, 
 534; D, I, 229; L, 169; N, 
 208. 
 French measures, E, 18; J, 94. 
 
 weights, E, 100. 
 Fresnel's lens, E, 521. 
 
 rhomb, J, 565. 
 Friction, A, vn, 758; B, 175; D, i, 57; 
 
 F, 85; G, 112; H, 315; J, 12, 27. 
 advantage from, E, 141 ; N, 71 ; G, 
 
 113. 
 against space, heat developed by, L, 
 
 18. 
 
 angle of, N, 70. 
 
 Babbage's experiments on, E, 227. 
 boiling of water by, Bumford's experi- 
 ments, L, 24. 
 fully described, L, 69. 
 
40 
 
 Friction, boiling of water by, to what 
 
 due, L, 128. 
 Coulomb's apparatus for measuring, 
 
 E, 222, 225. 
 results, E, 226. 
 definition of, K, 30. 
 developes heat, see under Heat. 
 how diminished, G, 112. 
 during motion, E, 138. 
 of fluids upon fluids, F, 132. 
 solids, F, 132. 
 
 homogeneous substances, K, 33. 
 how measured, N, 69. 
 kinds of, G, 112. 
 laws of, N, 69. 
 liquefaction of ice by, L, pp. 40, 107, 
 
 et seq. 
 of liquids against liquids, A, IX, 416; 
 
 J, 166. 
 
 solids, A, ix, 415; J, 166. 
 produces electricity, E, 809; K, 33, 
 
 see Electricity, 
 rolling, B, 177; K, 224; E, 139; 
 
 N, 71; G, 112. 
 Coulomb's apparatus, E, 225 ; 
 
 E, 140. 
 
 rythmic character of, M, 217. 
 sliding, B, 176; E, 220; E, 137; 
 
 G, 112. 
 
 source of, N, 69. 
 starting, E 221 ; E, 138. 
 
 Coulomb's apparatus for, E, 
 
 222. 
 
 wheels, J, 52. 
 Frigorific rays, J, 335. 
 Fringes, interference, J, 545. See Light, 
 
 interference of. 
 Frost, A, vii, 773; E, 1079; E, 977; 
 
 G, 272; 1,251; J, 846. 
 means of preserving plants from, L, 
 
 418; why an efficient, L, 418. 
 bearer, Wollaston's, see Cryophorus. 
 Frothing, see Liquids. 
 Fuel, value of, E, 6i>7; E, 753, 716; 
 
 G, 265. 
 Fulcrum, A, xi, 327; C, 97; G, 93; J, 
 
 23; N, 42. 
 
 Fulgurites, A, vin, 2; F, 209. 
 Fulminating pane, J, 652. 
 Fulmination, A, \ in. 5. 
 
 Furnaces, A, vm, 24. 
 
 blowers for, E, 282. 
 
 Chilson's, E, 702. 
 
 hot air, C, 542; E, 702; E, 729; 
 
 G, 264. 
 
 hot water, E, 703, 704. 
 Siemen's, A, '64, 748; Crookes and 
 Rohrig's Metallurgy contains an 
 account of Bessemer's pressure 
 furnace, also "Engineering" for 
 1869. 
 
 Furs, why used for clothing, G, 219. 
 Fuse, Abel's, J, 674. 
 Chatham's, J, 709. 
 Fusibility, A, vm, 32. 
 
 of metals (table), D, n, 671. 
 Fusible metal, I), 11, 973 ; J, 264. 
 Fusing points, effect of pressure upon, 
 D, I, 219, note; J, 264; 
 L, 119. 
 
 of bodies which con- 
 tnict on solidifying :ire 
 raised by pressure, L, 
 119. 
 
 of bodies which expand 
 on solidifying are low- 
 ered by pressure, L, 
 119 147. 
 
 fixed, and why, D, i. 219. 
 table of, D, I, 219. 
 of various bodies, A, vm, 
 
 32. 
 Fusion, A, vm, 32; B, 494; H, 317; I, 
 
 219; J, 263. 
 
 of ice by friction, L, 40, 108. 
 influence of pressure on, L, 120. 
 latent heat of, I, 220; J, 377. 
 laws of, E, 611; E, 658, J, 263. 
 peculiar in some solids, E, 659. 
 of refractory materials, A, in, 384. 
 solids, C, 548, 553. 
 
 change of volume attending, 
 
 C, 557. 
 
 temperature of, E, 658; N, 209. 
 vitreous, J, 264. 
 
 Galactometer, A, vm, 41. 
 
 Galleries, whispering, E, 436; E, 
 
 356; J, 183. 
 Gallon, imperial, C, 14; J, 94. 
 
41 
 
 Galvani's experiment, B, 402 ; I, 432. 
 
 .theory, E, 965. 
 Galvanic battery, see Battery, 
 current, see Voltaic current. 
 Galvanism, see Electricity. 
 Galvanized iron, A, vm, 65; D, n, 
 
 848; G, 415. 
 
 Galvanometer, see Electrometer. 
 . Galvano-plastics, see Electro-metal- 
 lurgy. 
 
 Galvanoscope, see Electroscope. 
 Gamut, see Musical scale. 
 Gas, A, vm, 93. 
 
 carbonic acid, E, 647. 
 
 apparatus for solidify- 
 ing, E, 650, 651. 
 liquid and solid, E, 652. 
 combustion of, L, 60. 
 denned, G, 23, 29; L, 63, 75; N, 14. 
 illuminating power of, L, 63. 
 illumination, products of, E, 721. 
 from soda water consumes heat, L, 28. 
 battery, see Battery. 
 jet, musical note of, E, 382. 
 Gaseous currents, properties of, F, 122. 
 state, J, 2 ; L, 75. 
 
 crystallization from the, E, 81. 
 Gases, B, 116; E, 252; F, 51. 
 
 absorb those rays of heat which they 
 
 emit, L, 426. 
 absorbed by porous bodies, A, in, 482 ; 
 
 F, 62. 
 absorption of, C, 392 ; F, 62. 
 
 by charcoal, C, 380; D, 
 
 I, 79. 
 
 liquids, B, 147; J, 
 
 140. See Solubility. 
 
 solids, C, 379, 381; 
 
 E, 307, 353. 
 absorptive power for radiant force, L, 
 
 351, et seq. 
 
 adhesion to solids, A, xm, 414. 
 are analogous to vapors, D, I, 56, 251. 
 analysis of, by absorption and formulas 
 
 for, C, 411. 
 
 analytical classification of, D, n, 657. 
 apparatus for compression of, C, 598; 
 
 E, 650, 651. 
 
 Archimedes's principle applied to, J, 
 141. 
 
 Gases, buoyancy of, C, 268. 
 
 combine under the influence of plati- 
 num, D, n, 1098. 
 compressed, escape of, E, 358. 
 compressibility of, A, xm, 410; C, 
 115, 273, 648; E, 274,277; J, 
 111, 131. 
 compressibility of, experiments on, C, 
 
 299. 
 
 laws of, C, 287. 
 limit to, C, 301. 
 condensation of, C, 592; F, 51; E, 
 
 653, 649. 
 
 apparatus of Nat- 
 
 terer, C, 
 
 598; J, 
 
 297. 
 
 of Thilorier, 
 
 C, 596. 
 by cold, 593. 
 
 pressure, C, 594. 
 Faraday's experi- 
 ments on, C, 595, 
 599. 
 
 heat from the, C, 648. 
 by platinum, D, I, 
 
 80, and n, 1097. 
 condensed, boiling points of, C, 592. 
 
 curves of pressure of, D, I, 
 
 258. 
 
 freezing points of, C, 599. 
 gauges for estimating pres- 
 sure of, D, I, 255. 
 latent heat of, C, 609. 
 low temperature from, C, 
 
 610. 
 maximum tension of, C, 
 
 593, 595. 
 pressure guages for, D, I, 
 
 255. 
 
 conductivity of, (electric), D, I, 366; 
 J, 323; (thermal) is low. B, 568 
 or 548; C, 657; E, 561; E, 620; 
 F, 366; L, 252. 
 constitution of, L, 76. 
 cooling effect on wire conveying vol- 
 taic current, D, I, 363. 
 correction of, for pressure, D, I, 48. 
 
 temperature, D, I, 
 180. 
 
42 
 
 Gases, definition of quantity of, C, 394. 
 density of, E, 552; E, 611; F, 116; 
 
 1,218; J, 259. 
 diminishes with increase of 
 
 temperature, A, xm, 412. 
 table, E, 553. 
 
 diamagnetism of, D, i, 419; J, 807. 
 diffusion, A, vi, 471 ; C, 419; D, I, 81; 
 
 E, 348 ; F, 64. 
 Dalton's theory of the, C, 
 
 422; D, I, 89^ 
 of, law of, D, I, 83. 
 
 method of illustrating, C, 
 
 419, 420, 423 ; E, 349. 
 
 table of the, D, I, 84; E, 
 
 350. 
 
 direction of pressure of, C, 265. 
 how distinguished from each other, D, 
 
 II, 657, et seq. 
 from liquids, C, 273. 
 vapors, C, 685. 
 
 dynamic radiation of, (table), L, 368. 
 effusion of, C, 412, 414; D, I, 84; J, 
 
 Iii7. 
 
 formula for, C, 415. 
 elasticity of, A, n, 309, and xm, 410; 
 
 C. 115. 
 
 permanent, C, 274. 
 endosmose of, E, 306 ; J, 106. 
 escape of compressed, E 358; F, 132. 
 expand by a constant increment for 
 every degree above 32 ( Fah.), L, 80. 
 expansion of, A,xm, 410; B,493; E, 
 545; E, 253; J, 111, 
 259, 262. Compare 
 Expansion, 
 coefficient of, C,528; L, 
 
 81. 
 
 force, J, 244. 
 formulae for, C, 529, 631, 
 
 532. 
 
 by heat, D, I, 169; G, 232. 
 laws of the, C, 632; E, 
 546; E, 
 606. 
 applications. 
 
 1,216. 
 methods of determining, 
 
 C, 530. 
 
 table of, D, i, 170; E, 
 647. 
 
 Gases, feeble varnished by powerful, L, 
 
 383. 
 
 fluidity of, C, 263. 
 formation of vapor in, C, 636. 
 formulae to compute changes in vol- 
 ume of, E, 548, 549. 
 reduce volumes of, to 
 standard 
 pressure, 
 C, 314. 
 of moist, 
 to stand- 
 ard pres- 
 sure, C, 
 637. 
 general properties of, A, xm, 410 ; I, 
 
 105; J, 110. 
 law of volumes, D, i, 21; laws of 
 
 mixture of, J, 139. 
 liquefaction of, D, I, 251, 257; I, 242; 
 
 J, 296-299. 
 liquid and solid, properties of, E, 
 
 691 ; E, 652. 
 table of, D, I, 257; E, 654; E, 
 
 689, and -XX. 
 magnetism of, I), i, 420. 
 measurement of, B, 148 ; C, 679. 
 mechanical condition of, C, 263; E, 
 
 254. 
 
 method of weighing, C, 270. 
 mixture of liquids and, J, 139, 140. 
 
 vapors, J, 300. 
 movement of, in pipes, A, xm, 413; 
 
 B, 197. 
 passage through membranes, C, 425 ; 
 
 D, i, 88. 
 
 pressure exerted by, on containing 
 vessels, A, xm, 411; J, 112. 
 due to gravity, C, 265. 
 problems in, J, 112. 
 properties of, G, 23. 
 radiative power of, L, 358, et seq. 
 refractive powers of, D, i, 129. 
 retardation of flow of, in tubes, A, 
 
 xm, 413. 
 
 simple and compound, E, 311. 
 solidification of, D, i, 253, 257. 
 
 table of, D, I, 257. 
 solubility in water, D, i, 78. 
 
 influence of heat 
 upon, D, i, 66. 
 
48 
 
 Cases, solubility in water, formulas for, 
 C, 394, 406, 407 ; 409 ; table, D, 
 I, 78. 
 
 specific gravities of, C, 93, 273, 670; 
 E, 553; F, 
 116. 
 
 determination of 
 the, C, 671; E, 
 552; by ef- 
 fusion, C, 414. 
 Deville and 
 Troost's method 
 of finding, J, 
 308; Dumas's 
 method, J, 307 ; 
 Gay - Lussac's 
 method, J, 305. 
 (table), E, 553. 
 heat of, E, 652, 653. 
 standard pressure for, D, i, 27, 49. 
 
 temperature for, D, i, 180. 
 tension of, A, xm, 410 ; C, 593. 
 definition, C, 263. 
 augmented by heat, A, 
 
 xm, 411. 
 transmit pressure in all directions, A, 
 
 xm, 411 ; C, 264. 
 
 transpirability of, table of, D, I, 86. 
 transpiration of, C, 417 ; E, 351 ; J, 
 
 107. 
 and vapors identical, E, 645; E, 
 
 648. 
 velocities of discharge of from orifices, 
 
 A, xm, 413. 
 volume of, C, 679 ; E, 608. 
 
 how reduced to standard 
 
 pressure, C, 313. 
 moist reduced to standard 
 
 pressure, C, 637. 
 weight of, C, 270, 667; J, 112. 
 weight of a cubic centimetre, form- 
 ula for, C, 668, 669, 670. 
 which have not yet been liquefied, D, 
 
 i, 259. 
 Gas holders, B, 197 ; C, 314 ; D, I, 47 ; G, 
 
 179. 
 
 Gassiot's cascade, E, 935. 
 Gasometers, see Gas holders. 
 Gay-Lussac's laws for the expansion 
 
 of gases, E, 606. 
 Gauge, mercurial, N, 156. 
 
 Gears in wheelwork, G, 101. 
 Geissler's tube?, J, 154, 799. 
 Germ force, K, 411. 
 Germination, dynamics of, K, 413. 
 Generative force in insects, K, 425. 
 Geysers, A, vin, 231; II, 323. 
 
 the great Iceland, L, 133. 
 
 Bunsen's theory of, L, 139. 
 
 temperature of, L, 138. 
 Gilding, A, vin, 250; D, n, 1052. 
 
 of the daguerrotype plate, D, n, 1144. 
 Gimbals, A, vin, 257 ; J, 588. 
 Glacial epoch, theories of the, L, 206. 
 Glaciers, A, vin, 268 ; J, 850. 
 
 ancient, evidences of, in various 
 places, L, 203. 
 
 central parts move fastest, L, 209. 
 
 cold alone cannot produce, L, 206. 
 
 formation of, L, 198. 
 
 maximum motion of, L, 211. 
 
 motion of, described, L, 198, et seq. 
 retarded cause of, L, 211. 
 
 movement of, L, 208. 
 
 point of swiftest motion shifts, L, 210. 
 
 rate of motion, L, 213. 
 
 regelation theory of, L, 199, et seq. 
 
 theories of the cause of their motion, L, 
 198, et seq., 208, et seq. 
 
 viscous theory of, L, 198. 
 Glaisher's balloon ascents, J, 143. 
 
 factors, J, 315. 
 Glass, A, vm, 281. 
 
 absorption of heat by, see Heat. 
 
 annealing of, see Annealing, 
 object of, D, n, 769. 
 
 broken by a grain of quartz, L, 99. 
 
 covers, aberration of, E, 510. 
 
 devitrified, D, 11, 763. 
 
 disintegration of, D, II, 768. 
 
 expansion of, A, xv, 429; C, 498, 499; 
 D, i, 166, 175; J, 250. 
 
 fire screens, philosophy v of, L, 319. 
 
 for optical purposes, A, xv, 354. 
 
 properties of, D, n, 759. 
 
 systems of fringes seen in unannealed, 
 F, 332. 
 
 temper of, E, 178. 
 Glasses, periscopic, J, 528. 
 Globe, artificial, A, vm, 299. 
 Glottis, E, 471; E, 388; G, 203. 
 Glues, why adhesive, G, 25. 
 
44 
 
 Gold's steam heaters, E, 732. 
 Goniometers, A, vm, 361; C, 177-183; 
 
 D, i, 97,98; E, 73,74; J, 442. 
 Goniometry, C, 181. 
 Governor, see Centrifugal. 
 Graduation of thermometers, E, 569. 
 Grain weight, origin of, G, 34. 
 
 bearing plants, construction of stems 
 
 of, G, 118. 
 
 Gramme, definition of the, C, 89. 
 Graphic representation of sound vibra- 
 tions on 
 smoked 
 glass, M, 
 69. 
 
 changes in 
 velocity, J, 
 34. 
 
 Gratings, J, 46. 
 Gravesande's ring, J, 227. 
 Gravimeter, see Hydrometer. 
 Gravity, or Gravitation, A, vm, 427; 
 B, 34; D, i, 24; E, 135; E, 58; 
 F, 64, 82; G, 30; H, 326; J, 12, 41, 
 42. 
 
 acceleration of, C, 65. 
 application of the theory to Astron- 
 omy, E, 136. 
 Borda and Cassini's experiments on, 
 
 C,74. 
 
 but half understand, K, 366. 
 causes of variations of earth's, C, 77 ; 
 
 J, 69. 
 
 which oppose, F, 86. 
 centre of, see Centre of Gravity, 
 definition of, C, 66. 
 directions of the force of, C, 57 ; E, 
 
 140. 
 
 earth's rotation affects, E, 94. 
 effects of, F, 82 ; G, 63. 
 
 on falling bodies, F, 82. 
 on the planets, I, 40. 
 examples of, E, 4. 
 force of, F, 82 ; I, 46. 
 
 less at equator than at poles, 
 
 D, I, 24. 
 
 implies a plenum, K, 368. 
 intensity of, equal, F, 66. 
 
 formula for, C, 65 ; F, 83. 
 at different latitudes, 
 C,77. 
 
 Gravity, intensity of terrestrial, J, 59. 
 
 varies with lati- 
 tude, E, 
 90. 
 
 from sphe- 
 roidal 
 form of 
 the earth 
 E, 91. 
 variable, N, 27. 
 irregularities of, C, 77. 
 is it a force? K, 399, 340, 341. 
 law of, C, 86; E, 4; F, 65; H, 826. 
 lateral, F, 66. 
 
 local variations of, E, 139. 
 measured by pendulum, C, 73; E, 
 
 88. 
 movement of bodies by, F, 82 ; E, 
 
 151; E, 70. 
 
 point of application of earth's, C, 58. 
 proportional to quantity of matter, C, 
 
 65. 
 relation to conservation of force, K, 
 
 363. 
 
 in relation to other forces, K, 170, 25H. 
 resultant of forces of, C, 59. 
 specific, see Specific Gravity. 
 a standard of comparison of weights 
 
 and measures, D, i, 24. 
 terrestrial, E, 137; G, 32; J, 42; N, 
 
 82. 
 
 not thoroughly understood, K, 366. 
 value of, at different latitudes, C, 76. 
 variation of with height, E, 95. 
 
 formula for, 
 
 C, 86. 
 
 varies with distance, C, 85. 
 velocity imparted to a body by, L, 56. 
 Green wood, why unprofitable to burn, 
 
 G, 266. , 
 
 Gridiron pendulum, see Pendulum. 
 Grimaldi's fringes, A, vi, 470. 
 Grindstones, how broken by centrifu- 
 gal force, G, 80. 
 Ground ice, D, i, 202, note. 
 Growth of organized beings, E, 52. 
 Guerick's apparatus, E, 677. 
 Gulf Stream, J, 865; D, 191; L, 193. 
 
 its influence upon the cli- 
 mate of Northern Eu- 
 rope, L, 193. 
 
45 
 
 Gun, essential properties of the, G, 76. 
 
 paper, A, '66, 388. 
 .Gunpowder, effective limit of the force 
 
 of, G, 77. 
 
 Gunter's chain, A^ vm, 586. 
 line, A, vm, 586. 
 quadrant, A, vm, 586. 
 Gurgle of a bottle explained, G, 180. 
 Gyroscope, A, vm, 615 ; E, 181 ; E, 
 
 57; N, 102. 
 
 produces musical sounds, M, 52. 
 proves the rotation of the earth, see 
 earth. 
 
 Haidinger's fringes, H, 334. 
 
 Hail, A, vm, 636; B, 603; E, 986; 
 
 G, 273-281 ; I, 251, 428 ; J, 848. 
 stones, formation of, G, 281. 
 storms, B, 604; E, 1082; G, 281. 
 Haldat's apparatus, J, 73. 
 Hallstrom's experiments, J, 254. 
 Halos, B, 612; E, 841; E,; 537; G, 
 
 336 ; H, 335 ; J, 636. 
 Hammering, E 179. 
 Hardening of steel, D, n, 888; E, 
 
 178. 
 Hardness, C, 208; E, 176; F, 51; G, 
 
 26 ; H, 336 ; I, 71 ; J, 3. 
 of metals, D, n, 666. 
 
 minerals, C, 209; D, I, 53. 
 scale of, A, vm, 716; C, 208, 209; D, 
 
 I, 53; J, 68. 
 Harmonic tones of strings, M, 115. 
 
 triad, J, 192. 
 
 Harmonica, chemical, A, vm, 728; J, 
 211; L, 279, 293; M, 137; condi- 
 tion of flame produced by, L, 295. 
 Harmonics, A, vm, 728, 730; F, 147; 
 
 H, 336; J, 196; N, 192. 
 grave, J, 199. 
 Harmony, A, vm, 728, 729; E, 448; 
 
 E, 365; M, 286; N, 191. 
 conditions of, M, 289 ; N, 191, 
 Euler's theory of, M, 287, 296. 
 influence of overtones on, M, 301. 
 perfect, M, 288. 
 Pythagorean notions of. 
 Harp, Marloye's, J, 214. 
 Harpsichord, A, vm, 736. 
 Haunted houses, explanation of, G, 200. 
 Hearing, E, 341 ; G, 201. 
 
 Hearing of animals, E, 396. 
 
 conditions for distinctness in, G, 200. 
 limits of, D, I, 210, note ; G, 203 ; M, 
 
 71, 84. 
 
 loss of (artificial), M, 74, 85. 
 mechanism of, M, 323, 324 ; nerve of, 
 
 B, 251; M, 1. 
 organ of, B, 248; E, 393; N, 197. 
 
 See Ear. 
 
 trumpet, E, 439 j N, 186. 
 Heat, A, ix, 15, xv, 44; B, 479; D, I, 
 161-164; E, 488; E, 564; G, 
 205; H, 338; I, 183; J, 226; L, 437, 
 et seq. 
 absorber of, qualities needed to form a 
 
 good, L, 364. 
 
 absorption of, A, ix, 18, xi, 416; B, 
 543; D, I, 198; E, 
 , 578; E, 637; F, 
 
 378; G, 225; H, 2; 
 I, 203; L, 306, 316, 
 317. 
 
 by dry air no greater 
 than by a 
 vacuum, 
 L, 348. 
 is scarcely 
 apprecia- 
 ble, L, 
 341, 349. 
 aqueous vapor, L, 
 
 390, et seq. 
 ammonia gas, L , 
 
 362. 
 carbonic acid gas, 
 
 L, 359, et seq. 
 carbonic oxide, L, 
 359, et seq. (ta- 
 ble), L, 357. 
 chlorhydric or mu- 
 riatic acid, L, 365. 
 chlorine, L, 362. 
 coal gas, L, 349. 
 coats of tin and 
 
 whiting, L, 304. 
 color influences, F, 379. 
 connection of, with radia- 
 tion and reflection, D, i, 
 199. 
 
 of different kinds of heat 
 (table), D, I, 204. 
 
46 
 
 Heat, absorption of, during evaporation, 
 
 A, IX, 434 ; 
 
 D, I, 200; 
 
 229 ;F, 370. 
 
 expansion, A, ix, 
 
 434; C, 475. 
 melting or thaw- 
 ing, A, ix, 20. 
 Franklin's experiments, 
 
 C, 653. 
 by gases, determined, L, 
 
 381, 368. 
 e 1 e m e ntary 
 and com- 
 pound, L, 
 365 ; 358, 
 et seq. 
 
 at atmos- 
 pheric ten- 
 sion, L, 
 361. 
 
 at less ten- 
 sion than 
 an atmos- 
 phere, L, 
 363. 
 
 glass of different 
 thickness, L, 316, 
 310. 
 
 hydrogen, L, 359, 
 tt *tq-, is scarce- 
 ly appreciable, L, 
 349. 
 
 influence of color, F, 379. 
 by lampblack, power- 
 ful, L, 366. 
 marsh gas, L, 361. 
 metals is low, L, 
 806 ;E, 578 (table), 
 in melting, A, ix, 20. 
 modified by what, E, 
 
 580. 
 
 by moisture contained 
 in bibulous paper, 
 L, 410. 
 nitrogen, L, 360, et 
 
 seq., 349. 
 nitrous oxide, L, 
 
 360. 
 
 defiant gas, L, 349, 
 351, 353, (table). 
 
 Heat, absorption of, by oxygen, L, 349, 
 
 360, etseq. 
 perfumes (table), 
 
 L, 374. 
 power of, how modified, 
 
 E, 580. 
 
 proportion to density of 
 gas at low tensions, 
 L, 353. 
 
 reciprocal with radia- 
 tion, D, I, 199; L, 
 303, 305. 
 
 by selenite, L, 316. 
 varies with source, D, 
 
 I, 203. 
 by sulphurous acid, L, 
 
 362. 
 
 sulphuretted hydro- 
 gen, L, 362. 
 takes place within a 
 
 body, L, 314. 
 is transfer, not annihil- 
 ation, L, 356. 
 by vapors (table), L, 
 
 868-354. 
 in vaporization, D, i, 
 
 200,229; F, 370. 
 by the vapors of many 
 volatile organic liq- 
 uids, such as alcohol, 
 ether, benzol, chloro- 
 form, etc, L, 354-368. 
 action of, on matter, E, 5f56. 
 
 mixed oxygen and hy- 
 drogen, L, 281. 
 
 amount developed by chemical action, 
 E, 751; L, 
 163. 
 
 the collision of a 
 
 falling body, 
 
 law of, L, 56. 
 
 the collision of 
 
 meteors with 
 
 the sun, L, 436. 
 
 combination of 
 
 carbon and 
 
 oxygen, L, 163. 
 
 combination of 
 
 hydrogen and 
 
 oxygen to form 
 
 water, L, 163. 
 
47 
 
 Heat} amount developed by the destruc- 
 tion of moving 
 force, L, 57. 
 by the expenditure 
 of a given 
 amount of 
 force, L, 52, et 
 seq. 
 
 the impact of pro- 
 jectiles, L, 56. 
 stopping the mo- 
 tion of a rifle 
 ball, L, 56. 
 
 that would be developed by 
 the falling of the earth or 
 the planets into the sun, L, 
 57, 443; or by stoppage of 
 the earth or a planet in its 
 orbit, L, 57, 443. 
 analysis, J, 343. 
 animal, A, i, 591 ; B, 551 ; D, in, 752 ; 
 
 E, 756; K, 324. 
 antagonistic to cohesion, D, I, 33. 
 aqueous vapor absorbs those rays of 
 
 which if emits, L, 426. 
 augments as the square of the veloci- 
 ty when a body is stopped, L, 56. 
 Bacon's conception of, L, 66. 
 calculation of amount developed by 
 
 the impact of projectiles, L, 56. 
 calculation of the mechanical equiva- 
 lent of, L, 85. 
 capacity for, A, ix, 19; F, 367; G, 
 
 247; L, 38; N, 206. 
 is different in different bodies, 
 
 L, 38. 
 
 explained by reference to in- 
 terior work, L, 159. 
 is increased by rarefaction 
 and diminished by com- 
 pression of the body, A, 
 ix, 19. 
 for, means of determining, 
 
 L, 158. 
 
 of capillarity, E, 741. 
 causes of, F, 359. See below, sources 
 
 of. 
 
 causes change of aggregation, L, 161. 
 causes of its distribution on earth's 
 surface, L, 189, 193. 
 
 Heat, characteristics of, G, 206. 
 
 central of the earth, see below, earth's 
 
 interior, 
 chemical action of, D, II, 1106; E, 
 
 757-748; F, 375; K, 64. 
 chemical and magnetic influence of, 
 
 K, 64. 
 of chemical action, E, 748-757; L, 
 
 163; G, 212. 
 circular polarization of, see below, 
 
 polarization, 
 and cohesion, D, I, 33. 
 and cold, F, 360; opposite effects of 
 
 on thermo-electric pile, L, 16. 
 coloration, E, 646, 
 combined, F, 359. 
 of combustion, C, 649; D, in, 789; 
 
 E, 749; J, 401. 
 Favre and Silber- 
 rnann s determina- 
 tion of, D, m,792; 
 J, 401. 
 communication of, A, ix, 17; E, 554; 
 
 E, 612; G,216. 
 compound bodies are good absorbers 
 
 and radiators of, why, L, 365. 
 conducting power of animal sub- 
 . stances (ta- 
 ble), L, 242, 
 246; E, 
 564. 
 
 apparatus for 
 finding, E, 
 556; L, 
 233. 
 
 the bark of 
 trees is low, 
 L, 242. 
 bodies, how 
 diminished, 
 G, 218. 
 clothing is 
 low, A, ix, 
 17; E, 
 625; E, 
 566; F, 
 366 ; L, 
 246 ; G, 
 220. 
 
48 
 
 Heat, conducting power of crystals, E, 
 559; E, 
 616; H, 
 141; L, 
 231, et seq. 
 c r y s tallized 
 silica is 
 high, L, 
 242. 
 
 gases, C, 657; 
 E, 561; 
 E, 620; 
 I, 209; J, 
 308 ;L, 255. 
 gases, Mag- 
 nus' experi- 
 ments, L, 
 253. 
 
 gypsum is 
 
 low, L, 248. 
 
 hydrogen, L, 
 
 253, 255. 
 
 influenced by mo- 
 lecular struc- 
 ture, L, 231. 
 Ingenhouse's ex- 
 periment, J, 
 819; L, 223. 
 of ivory is low, 
 
 L, 242. 
 
 liquids, C, 656, 
 657; D, I, 
 188; E, 
 660; E, 
 619; 1,208; 
 J, 322; L, 
 252, 25.3, 
 313. 
 
 metals (table), 
 C, 656; D, 
 n, 188; E, 
 615; F, 
 223; H,139; 
 L, 221, 224; 
 J, 320, 321. 
 organic sub- 
 stances, E, 
 564; L, 
 241. 
 
 powders, E, 
 624, L. 247. 
 
 Heat, conducting power of solids, C, 654, 
 656, 635; E, 
 557; E, 
 614, 621, 
 622; F, 366; 
 I, 207; L, 
 231. 
 
 solids not al- 
 w a y s the 
 same in ev- 
 ery direc- 
 tion, D, i, 
 90; L, 231. 
 various sub- 
 stances, A, 
 ix, 17; 
 (table), D, i, 
 188; E, 
 662; E, 
 622,623; G, 
 216; J, 319; 
 L, 224; N, 
 203. 
 
 wood, A, ix, 17; 
 E,558; E, 
 617; L, 
 229, 232, 
 240; ap- 
 paratus for 
 ascertaining 
 L, 233. 
 
 conduction of, A, ix, 17; C, 659; D, i, 
 
 187; E, 555; E, 
 
 613; F, 365; H, 139; 
 
 J, 319; L, 219. 
 
 in crystals, C, 656; L 
 
 231. 
 defined and illustrated, 
 
 C, 655: L, 219. 
 formula for, C, 659. 
 Despretz's method of ob- 
 serving, L, 223. 
 in experiments on, the 
 specific heat should 
 be known, L. 243. 
 a parallel to that of elec- 
 tricity, L, 225. 
 a transmission of molec- 
 ular motion, L, 218. 
 three axes of in wood, 
 L, 241. 
 
49 
 
 Heat, conduction of, unequal in different 
 
 directions, D, I, 90; L, 231. 
 - conductors (bad) of, A, ix, 17; C, 
 654 ; L, 220, et seq. ; G, 
 216. 
 
 (good) are good conduc- 
 tors of electric- 
 it}^ L, 225. 
 prevent local ac- 
 c u m u 1 ation of 
 heat, L, 249. 
 
 of, fluids are bad, F, 366. 
 constant proportion between it and 
 
 work, L, 53. 
 consumed in change of aggregation, 
 
 L, 161, 164. 
 when compressed gases 
 
 expand, L, 27. 
 conferring potential en- 
 ergy on the ultimate 
 particles of matter, L, 
 162. 
 expansion, D, I, 213 ; L, 
 
 155. 
 forcing atoms asunder, 
 
 L, 155. 
 
 liquefaction, E, 607. 
 solution, F, 370. 
 work, L, 26. 
 , . the production of vapor, 
 
 L, 168, 206. 
 
 convection of, A, ix, 17; D, I, 191; E, 
 567; E, 626; F, 
 367; G, 216; I, 208; 
 J, 323; L, 191-193, 
 255. 
 
 in air, L, 181. 
 defined, L, 191. 
 examples of, L, 192. 
 in hydrogen, L, 255. 
 in liquids, D, i, 191 ; E, 
 
 568; L, 191. 
 converted into light, K, 63. 
 
 mechanical energy, L, 
 
 112, 155. 
 motion, A, ix, 21; L, 
 
 155. 
 
 organizing force, K, 412. 
 potential energy, L, 230, 
 155. 
 
 Heat converted into sound, L, 112, 117 
 Davy's views of, L, 24, 41. 
 definition of, C, 430; I, 182; K, 39, 
 
 226; L, 37. 
 terms of, E, 487. 
 depolarization of, F, 385. 
 developed by the arrest of a falling body 
 is proportional to the 
 height from which 
 the body falls, L, 55. 
 arresting revolving 
 iron by means ot 
 magnetism, A, xi, 
 71; L, 50. 
 change of aggregation, 
 
 L, 166. 
 
 chemical substitutions 
 (basic), D, m, 804, 
 table. 
 
 chemical union, A, ix, 
 21, v, 530; B,550; C, 
 649; D,l,12, m, 793; 
 E, 748-757; cause 
 of, K, 161 ; of acids 
 and bases, D, m, 
 805 ; of chlorine, 
 bromine and iodine 
 with other bodies, 
 D, in, 794. 
 collision of a leaden 
 
 ball, L, 55. 
 
 combustion of alcohol, 
 D, lit, 794;-of di- 
 morphous bodies, D, 
 in, 795; ; of ho- 
 mologous bodies, D, 
 in, 797 ; of poly- 
 meric bodies, D, in, 
 796; of fuel, A, VII, 
 778; E, 715, 753; 
 K, 261. 
 
 compression, D, I, 213; 
 K, 32 ; L, 
 19; E, 
 739. 
 
 of g a s e s , 
 A, ix, 21 ; 
 C,648;I, 
 240; L, 
 
50 
 
 Heat developed by condensation, A, ix, 
 
 20; C, 648; 1,240. 
 during crystallization, E, 
 
 88; L, 167. 
 the discharge of electricity, 
 
 F, 188. 
 drawing atoms together, L, 
 
 156. 
 
 electricity, A, ix, 21, and 
 vii, 65,66; D, 
 1,362; L,117, 
 226; E, 886, 
 887; F, 224; 
 J, 802. 
 in conductors, 
 
 D, i, 301 (ta- 
 ble). 
 
 by the extinction of light, 
 
 A, ix, 21. 
 fall of a body from 
 
 a height, L, 64. 
 falling water or mer- 
 cury, L, 20. 
 
 friction, A, ix, 21; C, 
 648; D, I, 162; 
 
 E, 735, 736; 
 G,214;H,339; 
 J,395;K,277; 
 L, 18, 23. 
 
 of air on solids, 
 
 L, 28. 
 
 ice, L, 40, 108. 
 railway axles, 
 
 L, 21. 
 
 Rumford's experi- 
 ments upon, L, 23. 
 of tidal wave, L, 
 
 440. 
 galvanic action, A, vn, 
 
 65, 66. 
 impact of particles ot 
 
 matter, L, 77. 
 liquids changing to sol- 
 ids, L, 166. 
 mechanical processes, 
 
 G,213; L, 17. 
 metallic precipitation 
 
 (table), D, HI, 802. 
 moistening, D, i, 163. 
 motion of ultimate par- 
 ticles of matter, L, 39. 
 
 Heat developed when motion of air is 
 
 stopped, L, 28, 45. 
 by percussion, A, xi, 71 ; C, 
 
 C, 648; D, I, 163; E, 
 740; J, 397; L, 19, 20, 
 28, 45, 50-55, 77. 
 
 pressure, J, 396 ; rota- 
 tion of matter in the 
 magnetic field, L, 51. 
 
 solidification, A, ix, 20; 
 
 D, I, 220; E, 615; E, 
 663; F, 370; L, 166. 
 
 stretching caoutchouc, L, 
 
 101. 
 
 vital action, G, 214. 
 waterfalls, L, 20. 
 diffraction of, E, 649. 
 diffusion of, G, 206; J, 354. 
 diminishes as the square of the dis- 
 tance, Melloni's proof, L, 299. 
 distinction between heat and ordinary 
 
 motion, L, 313. 
 distribution of, D, I, 208; J, 866. 
 
 in the electric spectrum, 
 
 L, 266. 
 dynamical effects of, K, 40. 
 
 theory of, A, ix, 20, 21 ; E, 
 707; E, 762; H, 338; 
 J, 341 ; L, 26, 39. 
 dynamic absorption of, L, 383. 
 
 radiation of, L, 383, 386, 
 
 388. 
 
 of the earth, sources of, A, xi, 415. 
 earth's interior, A, iv, 652 ; C, 647 ; K, 
 
 300. 
 
 rate of increase with 
 the depth, A, iv, 
 
 652. 
 Poisson's view of, A, 
 
 iv, 652. 
 
 elastic force of, E, 37. 
 of electric current, etc., see under 
 
 Electric and Electricity, 
 emission of, see below, radiation of. 
 evolution of, ; see above, develop- 
 excitution of, ) ment of. 
 
 expansion by, C, 430, 492, 493; D, I, 
 164; E, 589. 597, 606; F, 360; 
 G, 228; I, 183; L, 73, 104. 
 expansive force of, L, 78, 79, 154; G, 
 229. 
 
51 
 
 Heat, experiments of Andrews, D, in, 
 
 789. 
 of Favre and Silbermann, 
 
 D, in, 792. 
 
 fibrous substances are non-conduct- 
 ors of, G, 219. 
 
 forces are produced by, K, 57. 
 and force (mechanical), K, 262. 
 force only available by cooling, K, 228. 
 of fusion, C, 555, 559, 560; E, 658. 
 generated, see Heat developed, 
 general effects of, I, 183. 
 
 nature of, D, I, 161-164. 
 glaciers require for their formation, L, 
 
 206. 
 good absorbers of, are also powerful 
 
 radiators, L, 359. 
 greatest artificial, G, 212. 
 Helmholtz's calculation of the amount 
 that would be caused by stoppage 
 of earth's motion, L, 57. 
 Herschellian rays of, J, 344. 
 imparted to a gas under constant 
 pressure, L, 80; constant volume, 
 L, 82. 
 
 imponderable, E, 489; E, 11. 
 independence of, and light, E, 590. 
 indicated by the deflection of a mag- 
 netic needle, L, 15. 
 influence of, extends far into the earth, 
 
 G, 211. 
 
 on affinity, D, n, 1106. 
 influenced by the mechanical state of 
 
 the body,' L, 2# ; K, 57. 
 intense of compound blowpipe, A, in, 
 
 384. 
 
 interference of, E, 649. 
 of interior of earth, see above, earth's 
 
 interior. 
 
 interior work done by, L, 155. 
 isodiabatic lines of, H, 350. 
 latent, A, vii, 346, ix, 19, xv, 46; B, 
 496; C, 603; D, I, 161, 216; 
 E, 606; E, 655; F, 369; 
 G, 213; H, 348; I, 187; J, 
 265 ; K, 41, 348 ; L, 162 ; N, 207. 
 of alcohol vapor, D, i, 231. 
 application of the dynamical 
 theory to the phenomena of, 
 L, 150 ; in the case of steam, 
 C, 611. 
 
 Heat, latent, definition of, L, 162. 
 determination of, C, 603. 
 of ether vapor, 1), i, 231. 
 the experiments of Brix on, C, 
 
 604. 
 
 in equal volumes, C, 606. 
 of fusion, I, 220. 
 
 ice, D, i, 161-216. 
 illustrations of, C, 608. 
 Leslie's experiment upon, C, 
 
 609. 
 
 of liquids (table), D, i, 218; L, 
 165 ; and vapors, H, 348 ; L, 
 162. 
 
 Person's theory of, D, i, 217. 
 Regnault's experiments upon, 
 
 C, 607. 
 
 and sensible, of steam, A, xv, 
 46; D, I, 283; E, 638; E, 
 (table), XII; E, 609 (table), 
 of steam, A, xv, 46; B, 696; C, 
 606, 607. 632; D, I, 232; E, 
 637; F, 370; L, 40, 162; 
 N, 207; formula for, C, 
 607. 
 
 solid carbonic acid, C, 610. 
 is that consumed in conferring 
 potential energy on the ulti- 
 mate particles of matter, L, 
 - 162. 
 
 of vapors, B, 530 ; D, I, 230 ; I, 
 236; J, 379; L, 168; H, 
 348. 
 
 water, steam and aqueous 
 vapor, L, 40, 162, et seq., 
 206. 
 
 Watt's theory of, C, 606. 
 when rendered sensible, G, 246. 
 law of inverse squares applied to, L, 
 
 298. 
 and light, analogy of, E, 765; E, 
 
 591; L, 277, et seq. 
 by chemical and mechani- 
 cal action, E, 76L 
 possibly independent, D, I, 
 
 209*; E, 590. 
 relations between, G, 208; 
 
 E, 591. 
 living animals can bear intense, L, 
 
 229. 
 Locke's view of, L, 39. 
 
52 
 
 Heat lost by volcanoes, K, 310; by the 
 
 ocean, K, 311. 
 
 indicated by magnetic needle, L, 15. 
 from magnetism, E, 918. 
 material theory of, L, 37. 
 
 destroyed by Rum- 
 ford^ K, XXIII, 
 XXIV; L, 39. 
 means of detecting minute amounts 
 
 of, L, 342. 
 
 measurement of, compare Thermome- 
 ter, B, 636; D, i, 
 170, etseq; G, 206; 
 H, 342; L, 342,52, 
 et seq. 
 
 the amount gener- 
 ated by a given 
 e x p e n d i ture of 
 force, L, 52, et seq. 
 from mechanical action, see above, 
 
 developed by. 
 
 mechanical (or Joule's) equivalent of, 
 C, 484, 633; 
 E, 713- 
 715; E, 
 758-760; J, 
 480; K, 316, 
 891; L, 64, 
 83, et seq., 
 62, et seq.t 
 86, 87; M, 
 32-35. 
 its applications, 
 
 K, 353. 
 
 d e t ermination 
 of the, E, 
 713. Com- 
 pare Calor- 
 imeter. 
 
 Joule's experi- 
 ments, L, 25, 
 86; E,713, 
 714,715; H, 
 339. 
 
 Mayer's essay 
 upon, K, 316; 
 his views, L, 
 85. 
 
 theory of, see Heat, dy- 
 namical theorv. 
 
 Heat and motion, convertib ility of, B 
 
 652 ; K, 323. 
 a mode of molecular motion, A, ix, 
 
 21 ; L, 24, 39, 41, 70, 74-218, 301. 
 motion of, interferes with electrical 
 motion, L, 226 ; its motion is more 
 impeded by groups of atoms than 
 by single atoms, L, 301. 
 of the moon, D, i, 209; L, 421, 422. 
 
 mountain tops, K, 282. 
 mutual exchange of, between bodies, 
 
 I, 197. 
 nature of, G, 207; E, 488; L, 37, 
 
 et seq. 
 nocturnal radiation of, the cause of 
 
 dew, L, 414, et seq. 
 
 nocturnal radiation of, ice crop of In- 
 dia by, L, 418. 
 table of chilling 
 by, from Gla- 
 isher's, Wells' 
 and others' ex- 
 periments, L, 
 420. 
 not equally possessed by every body, 
 
 L, 220. 
 
 number of luminous and obscure rays 
 of, transmitted by alum, chromate 
 of potash, rock salt and selenite, L, 
 317. 
 
 obscure of the moon, almost wholly 
 absorbed by atmospheric 
 vapor, L, 422. 
 
 rays ef the spectrum, J, 
 344 ; L, 268 ; obey same 
 laws as light, L, 277. 
 ratio of luminous to obscure 
 rays from various sources, 
 L, 323. 
 
 transmutation of, J, 347. 
 lost by ocean, K, 311. 
 opacity of glass to, L, 310. 
 origin of terrestrial, E, 746. 
 origin of that produced in boring can- 
 non, L, 67. 
 
 passage of, through a vacuum, L, 258. 
 performance of work by, in a steam 
 
 engine, L, 132. 
 
 polarization of, D, I, 211; E, 649; 
 F, 334, 383,384; J, 674. 
 
53 
 
 Heat, polarization of, by mica, F, 384. 
 
 refraction and by 
 reflection, F, 384. 
 tourmaline, F, 384. 
 circular, F, 385, 386. 
 
 by reflection and 
 refraction, F, 
 386. 
 power of, in expanding bodies, L, 
 
 154. 
 
 practical application of, K, 77. 
 as producing motive power, K, 68. 
 produced by various causes, see Heat, 
 
 developed by. 
 produces the various forces, K, 57. 
 
 two kinds of motion in bodies, 
 
 L, 155. 
 the production of, is inexhaustible, L, 
 
 70. 
 
 propagation of, I, 196. 
 proximate causes of, F, 359. 
 quality of, defined, L, 317. 
 
 how changed, E, 770. 
 quantity of different, in all bodies, G, 
 
 247. 
 
 evolved during the com- 
 bustion of various sub- 
 stances, A, v, 530. 
 yielded up by different 
 bodies in cooling, L, 157. 
 and intensity, E, 771. 
 radiant, A, ix, 17, 18; B, 542; C, 651; 
 D, I, 197; E, 570; F, 
 376; H, 628; 1,204; J, 319- 
 325; L, 257, 265, et seq., N, 
 205. 
 
 absorption of, by different me- 
 *dia, B, 548 ; C, 
 652; E, 571; 
 F, 382; J,355, 
 338; L, 48, et 
 seq., 314, 373- 
 376, 378, 381, 
 383, et seq., 
 409. 
 by gases, L, 48^ 
 
 et seq. 
 vapors, L, 
 
 368. 
 
 occurs within the 
 body, L, 314. 
 
 Heat, radiant, action of aqueous vapor 
 
 on, L, 409 ; of the odors 
 
 of aromatic herbs on,L, 
 
 374 ;-of ozone on, L, 376, 
 
 378 ; of perfumes and 
 
 scents on, L, 373, et seq. 
 
 analogous to light, C, 651. 
 
 angle of incidence of, equals 
 
 angle of reflection, L, 274. 
 angular velocity of the re- 
 flected ray of, L, 276, 277. 
 apparatus used in investigat- 
 ing, D, i, 205; L, 345. 
 applications of, E, 581. 
 consists of undulations, F, 376. 
 effect of screens upon, F, 382. 
 emission of. by all bodies, C, 
 
 653; L, 273. 
 
 Franklin's experiments, C, 653. 
 as a hygrometer, L, 409. 
 influence of colors on, L, 302. 
 intensity of, E, 572 ; F, 377 ; 
 
 J, 327; L, 297, 297, et seq. 
 laws of, C, 651 ; F, 377 ; I, 196 ; 
 
 J, 326; L, 277, 297, et seq. 
 and light, analogy of, E, 765; 
 
 L, 274. 
 
 measurement of, J, 325. 
 Melloni's apparatus and re- 
 searches, D, I, 205; E, 
 642; J, 341; L, 310. 
 in its passage through diather- 
 mic bodies does not heat 
 them, L, 318, 320. 
 reflected by various bodies, F, 
 
 377. 
 
 to a focus, F, 376. 
 reflection of the ravs 
 of, C, 
 652, F, 
 377; L, 
 278,306. 
 of, from curved 
 surfaces, L, 
 279. 
 
 from parabo- 
 lic mirrors, 
 L, 280; 
 from plane 
 surfaces, 
 L, 274. 
 
54 
 
 Heat, radiant, refraction of, through 
 lenses, F, 382 ; through 
 prisms, F, 383. 
 sifting of, L, 321. 
 theory of exchanges of, L, 273. 
 transmission of, A, ix, 18; C, 
 652; E, 583; 
 E, 641; L, 
 307, 311 (table), 
 313. 
 
 influence of the 
 nature of the 
 screens on the, 
 E, 585; of 
 the source, E, 
 586. 
 
 of, through liquids 
 (Melloni's ta- 
 ble), L, 313; 
 solids and liq- 
 uids, L, 807, 
 311. 
 radiation of, A, ix, 17, 18; D, I, 197; 
 
 E, 570; 1,204. 
 and absorption, dynamic, 
 
 table of gases, L, 383. 
 dynamical effects of, K, 408, 
 
 404. 
 
 by gas- 
 e o u s 
 matter, 
 a paper 
 on, L, 
 409. 
 
 a gas or 
 v a por, 
 determ- 
 i n e d 
 without 
 exter- 
 nal heat 
 L, 381. 
 are re- 
 cipro- 
 cal, G, 
 216; J, 
 338; L, 
 303, 
 304. 
 
 of, amount of solar, D, I, 
 197; L, 431. 
 
 Heat, radiation of, by carbonic acid 
 gas, L, 359, et scq. ; 
 by carbonic oxide, L, 
 359. 
 
 causes dew, A, vi, 433. 
 cold, A, vi, 433; 
 
 J, 407. 
 
 effects of, K, 236. 
 effect of color, A, ix, 18; J, 
 339; L, 302; G, 
 222. 
 
 darkness and rough- 
 ness, A, ix, 18; J, 
 339; G, 222. 
 
 of, by gases and vapors, J, 
 346,360; L, 337,358,360, 
 et seq. 
 
 good and bad, L, 301. 
 is less influenced by nature 
 of a body than by the 
 state of its surface, A, ix, 
 18; F, 377. 
 of, by metals is low, L, 301, 
 
 417. 
 
 nitrogen, L, 360, et seq. 
 through moist air, L, 389. 
 by powders, J, 363. 
 ratio of obscure to lumin- 
 ous radiation in vari- 
 ous flames, L, 323. 
 is universal, E, 674 ; E, 
 
 633 ; G, 223. 
 in vacuo, D, I, 203. 
 by various bodies, E, 
 
 579; F, 378; 1,204. 
 rays, A, xr, 416; G, 224; I, 314; J, 
 
 325, 342, 343; L, 268. 
 absorption of, A, ix, 18. 
 beyond visible spectnim, L, 
 
 268. 
 reflection of, A, ix, 18; F, 376; 
 
 E,677; 1,202. 
 
 from different sources possess 
 different penetrating powers 
 in regard to different sub- 
 stances, A, xi, 416. 
 sifting of, by glass, water, etc., 
 
 L, 316. 
 transmission through solids, A, 
 
 ix, 18. 
 a rectilinear motion, L, 76. 
 
55 
 
 Heat, reflection of, A, ix, 18; D, i, 197; 
 
 E, 576; E, 635; F, 
 
 377; G, 224; I, 198, 
 
 200; J, 331, 335; K, 
 
 61 ; L, 274-280, 306. 
 
 from concave mirrors, I, 
 
 200 ; parabolic 
 
 mirrors, L, 279, et 
 
 seq. 
 
 conjugate mirrors, 
 
 D, I, 197, 200. 
 laws that govern the, I, 
 
 199; L, 274. 
 reflective power for, of bodies, E, 
 
 577, 580; I, 202, 205. 
 refraction of, D, i, 208; E, 592; E, 
 
 648; F, 382, 383. 
 relation of force to, E, 712. 
 to velocity, L, 56. 
 vital forces, K, 401, 420. 
 repulsion of, C, 118; L, 41, 107, 110. 
 
 Davy's view of the, L, 
 
 41, 107. 
 restored to universe by decay, K, 
 
 419. 
 
 Eumford's view of, L, 39, 41, 67. 
 scattered, J, 337. 
 sensible, A, ix, 19, xv, 46; G, 213; I, 
 
 187. 
 
 and latent, of steam at differ- 
 ent temperatures, A, xv, 
 46 ; D, i, 233 ; E, 638. 
 separation of, from light, F, 383. 
 sidereal, or Heat of stars, A, xi, 415. 
 solar, C, 647; D, i,197; E, 742-743; 
 G, 227; K, 236, 243, 264, 266, 
 276, 403-404; L, 431-436, 57. 
 amount of, C, 647; D, I, 197; L, 
 
 431; K. 243, 264. 
 its chemical origin, K, 266. 
 emission of, L, 431. 
 maintenance of, L, 435. 
 measure of, K, 264. 
 meteoric theory of, L, 57, 436, 
 
 440. 
 
 origin of, K, 276. 
 radiation of, J, 398 j K, 403, 404. 
 and sound, difference between the 
 
 waves of, L, 300. 
 
 sonorous motion converted into, M, 28, 
 177. 
 
 
 >, 
 
 Heat, sources of, A, ix, 23, 
 
 647 ;D, I, 1*2; E,V 
 716; E, -734-757; G,, 
 209; 1,255; J, 19^-406; 
 K, 261. See Hea^ytie- 
 velopment of. 
 chemical, A, ix, 23, 
 cosmical, A, ix, 23. 
 mechanical, A, ix, 23. 
 physical, A, ix, 23. 
 physiological, A, ix, 23. 
 a species of motion (Bacon's view), 
 L, 66. See above, a mode of motion, 
 specific, C, 464; D, I, 211, in, 784; E, 
 595; F, 368; J T 365; L, 
 158; G,247. 
 
 aid from, in fixing chemical! 
 equivalents, C, 471 ; D, i, 
 216, n, 1151; m, 784; E, 
 604, 605 ;E, 654; F, 368. 
 application of the dynamical 
 theory of heat to the phe- 
 nomena of, L, 150. 
 of a body in different states,. 
 E, 603; D,i,215 (table), 
 compression alters, D, i, 213 - f 
 
 E, 601. 
 
 how determined, L, 159; M, 
 31 ; J, 367- 
 370. 
 
 by mixture,. 
 C, 466-468. 
 
 of the elements, C, 466. 
 experimental illustrations of, 
 
 L, 157. 
 
 explained by reference to in- 
 terior work and to atomic 
 number, L, 159. 
 of gases,, C r 467-489;. E, 
 5S9; E, 652,. 
 652;- F, 369; J,. 
 375. 
 
 under constant 
 pressure, C, 477 ; . 
 does not vary 
 with the temper- 
 ature or pres- 
 sure, C, 477 ; or 
 volume, C, 480; 
 formula for, C, 
 481. 
 
56 
 
 Heat, specific, of gases, determination of, 
 from velocity of 
 sound, C, 482. 
 Dulong's experi- 
 ments and 
 laws, C, 483, 
 484, 489. 
 
 lead is low, L, 157. 
 liquids, C, 466, 475; 
 D, I, 215; I, 243; 
 is greater than that 
 of solids, C, 475 ;D, 
 I, 215. 
 
 masking the conducting 
 power of a body, L, 
 
 243. 
 mercury is low, D, I, 212; 
 
 L, 157. 
 
 platinum, C, 473. 
 relation to atomic weight, 
 see above, aid from in 
 fixing, 
 rises with the temperature 
 
 (table), D, I, 216. 
 Of solids, C, 466 ; D, I, 213, 
 in, 786; 1,243. 
 and liquids, C, 466. 
 determina- 
 tion of, 
 C, 466, 
 467. 
 
 table of, E, 600; L, 158. 
 unit of, C, 464; 472. 
 of various substances, A, 
 
 ix, 19; C, 466. 
 velocity of sound indicates 
 
 the, M, 31. 
 of water is highest of all, 
 
 C, 476; L, 160. 
 
 structure influences, K, 57 ; L, 247. 
 of the sun, see Heat, solar and side- 
 real. 
 
 terrestrial, F, 379; J, 398. 
 theories of, C, 430; F, 359; G, pp. 
 207, 208; 1, 182; L, 37. See Heat, 
 dynamical theory of. 
 transmission of, A, vi, 449 ; E, 583- 
 586; E, 641; G, 226; J, 319; L, 
 311-321, 
 
 Heat, transmission of through liquids 
 (Melloni's ta- 
 ble), L, 313. 
 through opaque 
 bodies, L, 
 321. 
 rock salt, A, 
 
 vi, 449. 
 screens (ta- 
 ble), E, 
 585, 586. 
 solids (Mel- 
 loni's ta- 
 ble), L, 
 311, 312, 
 317. 
 woo d, L , 
 
 233, 240. 
 transparency of bromine to, L, 366. 
 
 bisulphide of carbon 
 
 vapor, L, 309, 313. 
 transversal undulations of waves of, 
 
 L, 300. 
 unequal distribution of, in spectrum, 
 
 D, I, 208. 
 
 unit of, A, ix, 19, xv, 45; D, I, 139. 
 units of produced in combustion, K, 
 
 261. 
 
 universal law of, K, 261. 
 upon high mountains, K, 282. 
 velocity of, G, 223. 
 a vibratory motion, as thought by 
 
 Davy, L, 111. 
 lost by volcanoes, K, 310. 
 has no weight, G, 209. 
 and work, K, 326, 68. 
 
 Joule's experiments, L, 52. 
 Mayer's views, L, 52. 
 of steam engine, L, 132. 
 zero of, or Absolute zero, A, ix, 18; J, 
 
 407. 
 
 Heating of buildings, A, xvi, 208; D, 
 I, 192,221; E, 
 405, 700, 
 et seq.; E, 
 727, etseq.^G, 
 260 ;H, 354; I, 
 240; J, 402, 
 406. 
 
57 
 
 Heating of buildings by hot air fur- 
 naces, E, 
 702. 
 water, D, 
 I, 192; 
 E, 703; 
 H, 354; 
 Per- 
 kin's sys- 
 tem, E, 
 704. 
 open fires, E } 
 
 429. 
 
 steam, D, i, 
 221; E, 
 705 ; I, 240 ; 
 Gold's 
 system, E, 
 ' 705. 
 
 and cooling, laws of, F, 365. 
 Heights, measurement of, C, 304, 305 ; 
 D ; I, 226; E, 272, 679; F, 125: 
 G, 242; J, 127, 274; N, 169. 
 Heliometer, A, ix, 62, xv, 357; H, 358. 
 Heliostat, J, 442. 
 Heliotrope, A, ix, 63. 
 Helix, D, I, 382, 384; E, 1017, 1020; 
 
 E, 910; J, 26, 746; G, 432. 
 a magnet^while conveying an electric 
 
 current, D, I, 384. 
 electro-magnetic, D, i, 382. 
 magnetizing by a, E 7j 1020. 
 Herapath's polarizing salt, J, 554. 
 Hiero's fountain, B, 142; E, 377; E, 
 
 295 ; F, 136. 
 High pressure, see Steam. 
 Hoar frost, B, 596; F, 379; J, 846. 
 Homologous and Heterologous series 
 in chemistry, A, v, 42-44; D, in, 
 26-33. 
 
 Hope's experiment, J, 252. 
 Horn, A, ix, 276. 
 Horse, day's work of a, A, xi, 326. 
 mechanical efficiency of a, A, ix, 23. 
 power of a, A, xi, 326. 
 power, A, ix, 290, and xi, 326; E, 
 189, 686; E, 714; G, 88 
 J, 394. 
 
 machines, E, 187; E, 132. 
 nominal, A, xv, 57. 
 
 8 
 
 Horse works to best advantage when, A, 
 
 xi, 326, or 320. 
 Hot beds, influence of radiant heat in, 
 
 C, 654. 
 
 blast in metallurgy, D, n, 877. 
 Hotness, J, 225. 
 Hour, J, 10. 
 Humidity, absolute and relative, E, 
 
 1065; E, 972; G, 268. 
 Hurricanes, A, ix, 385; E, 968; G, 
 
 285. 
 
 space traversed by, G, 286. 
 where most frequent, G, 285. 
 velocity of, G, 286. 
 Hydraulic engines, cause of loss of 
 
 power in, G, pp. 158, 169. 
 press (Bramah's), A, in, 634, ix, 412; 
 
 C, 220; E, 254; E, 296; F, 
 137; G, 126, 127; I, 79; J, 79; N, 
 121, or 150. 
 
 ram, A, ix, 406; E, 378; G, 161, 
 
 162; H, 368; K, 4; N, 121, or 150. 
 tourniquet, J, 167. 
 Hydraulics, A, ix, 419; E, 213; G, 
 
 148; H, 362; J, 69. 
 
 Hydrodynamics, A, ix, 414; E, 233; 
 E 186; F, 129; H, 368; J, 69; I, 
 73; N, 118. 
 Hydro-Electric machine, A, vn, 62; 
 
 D, I, 310; F, 185; H, 227; J, 638. 
 Hydro-extractor, see Centrifugal dry- 
 ing machine. 
 
 Hydrogen, action on the voice of, M, 9. 
 
 Hydrogenium, i. e., Occluded hydro- 
 gen, A, '68, 100, 345. 
 
 Hydromechanics, A, ix, 412. 
 
 Hydrometer, A, n, 63, ix, 416; B, 
 
 101, 105; C, 249; D, I, 31; E, 
 
 212; F, 114; G, 141; H, 39, 372; 
 
 I, 103; J, 89, 310-316; N, 135. 
 
 Beatime's, A, ix, 416; B, 105; C, 253; 
 
 E, 268; E, 212; I, 102; J, 95; D, 
 in, 807 (table). 
 
 Brisson and Schmidtz's, B, 101. 
 Cartier's, A, IX, 416; N, 135. 
 Fahrenheit's, C, 251; J, 93. 
 formulas for, C, 251, 252. 
 Nicholson's, C, 250; E, 264; J, 90; 
 
 N, 136. 
 pump, N, 136. 
 
68 
 
 Hydrometer, Rousseau's, C, 255. 
 
 Twaddell's, (tables), A, ix, 416; D, 
 
 in, 808. 
 
 uses of tables for, J, 94. 
 of volume, constant, J, 95. 
 variable, J, 95. 
 Hydrostatic balance, B, 95; C, 248; E, 
 
 257 ; J, 85. 
 
 bellows, A, ix, 413; J, 75; N, 126. 
 paradox, A, ix, 413; C, 228; E, 
 253 ; E, 195 ; G, 126 ; H, 375 ; J, 76. 
 press, see Hydraulic press, 
 pressure, F, 107. 
 
 Hydrostatics, A, ix, 412; B, 80; E, 
 186; F, 104; G, 123; H, 373; I, 
 73; N, 118. 
 
 Hygrometer, A, vn, 345, ix, 419; B, 
 
 890; 0,639; E, 1066; E, 973; 
 
 F, 374; G, 269; H, 377; J, 310- 
 
 316. 
 
 August's, (chemical), A, ix, 421; E, 
 
 1066; F, 374; H,379; J, 310. 
 DanielPs, A, IX, 420; B, 591; C, 643; 
 D, I, 248; E, 1066; F, 374; H, 
 379; J, 312. 
 Deluc's, C, 645. 
 De Saussure's, A, ix, 419; B, 695; C, 
 
 645; J, 316; I, 247. 
 hair, C, 645; 1,247. 
 Regnault's, A, ix, 420; C, 642; J, 313. 
 use of radiant heat as an, L, 409. 
 wet bulb, A, ix, 421; C, 644; D, I, 
 250; F, 375; J, 314; formula and 
 factors for, D, I, 250, 251. 
 Hygrometry, A, ix, 419; C, 636, 638; 
 I, 245 : Dalton's laws of, C, 638; 
 problems in, J, 317. 
 Hygroscopes, A, vn, 345, ix, 419 , E, 
 
 1066; I, 246. 
 Hygroscopic state, J, 309. 
 
 substances, J, 309. 
 Hypothesis defined, E, 3. 
 of Grothuss, J, 721. 
 relation of, to law, C, 7. 
 Hypsometer, E, 634; E, 679; J, 
 285. 
 
 Ice, A, ix, 433; J, 848. 
 
 amount melted per minute by solar 
 radiation, Herschel's and Pouillet's 
 measurements, L, 431. 
 
 Ice, amount melted per hour by total 
 
 emission of sun, L$ 434. 
 artificial formation of, by nocturnal 
 
 radiation, L, 418. 
 bubbles of air in, cause of, G, 232; L, 
 
 329. 
 
 carrier or cryophorus, L, 169. 
 cause of freezing together of two 
 
 pieces of, L, 335. 
 currents produced by, E, 724. 
 dissected by heat, L, 123. 
 effect of heat upon, L, 324, et seq. 
 examination of water-blebs in, L, 334. 
 expansive force of, J, 23. 
 flowers, L, 122, et seq., 324, et seq. 
 formed in Bengal by nocturnal radia- 
 tion, L, 418. 
 heat developed by rubbing together 
 
 bits of, G, 206. 
 not homogeneous, L, 328. 
 liquefied by friction, L, 40, 108. 
 
 pressure, L, 121, 148, 32 8 
 machine, Twining's, E, 681. 
 moulding of ice by pressure, L, 200. 
 physical properties of, L, 146, 324. 
 power of absorbing heat, L, 320. 
 planes of freezing in, how recognized, 
 
 L, 324. 
 produced by escape of compressed 
 
 air, L, 46. 
 
 evaporation, F, 372. 
 proofs of non viscosity of, L, 214. 
 regelation theory of, L, 199, et seq. 
 specific gravity of, D, I, 94. 
 
 heat of, D, I, 215. 
 streams, see Glaciers, 
 structure and beauty of, L, 122. 
 theory of melting interior of, by con- 
 duction of heat, L, 332. 
 use of sawdust in preserving, G, 220. 
 viscous theory of, L, 198, 203, 214. 
 why it swims on water, L, 93. 
 Icebergs, A, ix, 436. 
 Iceland spar, J, 554. 
 Idio electrics, F, 170; J, 608. 
 Ignis fatuus, B, 613. 
 Ignition of vapor of bisulphide of car- 
 bon by compression, L, 43. 
 Illumination, products of, E, 721. 
 railway, E, 827; E, 520. 
 sufficiency of, E, 477. 
 
69 
 
 Images, distinctness of, conditions, J, 
 
 483. 
 
 ' distortion of, E, 768 ; G, 303. 
 formation of, by lenses, B, 282; E, 
 
 453; F, 294. 
 mirrors, concave, B, 
 265; E, 
 433; F, 
 284; I, 
 279; J, 
 437. 
 
 convex, E, 
 
 435; F, 285; 
 
 I, 282 ; J, 
 
 438. 
 
 inclined mirrors, E, 
 
 422; E, 740. 
 plane mirrors, E, 
 419; F,282; 1,271; 
 J, 428. 
 two plane mirrors, 
 
 E, 421: F, 282. 
 multiple in mirrors, E, 
 420; 1,273; J, 430. 
 by small apertures, E, 
 
 412; J, 417. 
 inversion of, J, 516. 
 inverted, in the eye, E, 470. 
 optical, F, 282. 
 
 ocular, brightness of, E, 784. 
 real, I, 279; J, 429. 
 repeated by inclined reflectors, E, 
 
 740. 
 
 secondary, B, 312. 
 vertical, J, 429. 
 virtual, E, 750 ; E, 434 ; I, 281 ; J, 
 
 429. 
 
 Imbibition, C, 363; I, 68. See Ab- 
 sorption. 
 
 heat produced by, J, 107. 
 Impact, E, 127; E, 112; H, 382. 
 of elastic bodies, E, 132; E, 182; 
 
 H, 382. 
 liquids upon solids, A, ix, 416; H, 
 
 372. 
 in relation to momentum, E, 112. 
 
 vis viva, E, 112. 
 results of, E, 112, 
 
 Impenetrability, C, 19; E, 19; E, 
 14: F, 50; G, 12, 13; H,385; I, 13; 
 J,3 
 
 Impenetrability of air, E, 314 ; E, { 
 
 259. 
 
 a property of matter, N, 15. 
 Imponderable matter, J, 3. 
 
 density of, F, 43. 
 elasticity of, F, 43. 
 effects of the undula- 
 tions of, F, 45. 
 Imponderables, E, 11. 
 Impressions of light and heat, E, { 
 
 766. 
 
 on our senses are interpreted with a 
 certain latitude by the mind, A, 
 xvi, 132. 
 
 Incandescence, E, 767. 
 Incidence, Angle of, G, 71. 
 Inch, J, 94; of water, E, 221. 
 Inclination compass, J, 591. 
 magnetic, F, 158, 160; J, 189. 
 map, isoclinal lines, E, 794 ; E, 889. 
 Inclined plane, A, xi, 327, 328; B, 48; 
 E, 208; E, 121, 
 124; F, 99; G, 105, 
 H, 386; I, 55; J, 24. 
 applications of, I, 57. 
 application of power to, 
 in different directions, 
 E, 209, 211. 
 effect of power applied 
 
 to, E, 212. 
 motion on, J, 50. 
 theory of, F, 100; G, 
 
 106. 
 
 Incombustible cloth, A, ix, 476. 
 Incrustations in steam boilers, see 
 
 Boilers. 
 Indestructibility of force, see Force, 
 
 conservation of matter, K, XII. 
 India rubber, shortened by heat, L, 102. 
 shortening of, Joule's ex- 
 periments on, L, 101. 
 stretching, produces heat, 
 
 L, 101. 
 Indicator, steam engine, A, xv, 55 ; H, 
 
 388. 
 
 Induction, electric, see Electricity; in- 
 duction of coil, see Coil. 
 RuhmkorfTs, A, xi, 69; E, 933, 934. 
 Ritchie's, A, xi, 69. 
 Saxton's, A, xi, 68. 
 Inductive philosophy, E, 4. 
 
60 
 
 Inertia, A, xi, 318, 321, 323; B, 33; C, 
 32; E, 27; E, 26; F, 56; G, 
 16, 17; H, 389; I, 14; J, 9, 12. 
 
 of air, E, 315; E, 260. 
 
 proportional to the quantity of matter, 
 
 E, 28. 
 
 relation to forces, K, 369. 
 Inorganic growth, E, 51. 
 Insulating stool, see Electric stool. 
 Insulation, see Electricity. 
 Intensity, see Electricity, Light, Sound. 
 Interaction of natural forces, K, 211. 
 Interference, see Light. 
 Interior work, different kinds of, L, 160. 
 
 done by heat, L, 155. 
 Interplanetary spaces, temperature of, 
 
 A, xi, 415. 
 
 Interval, E, 454; E, 371; 1, 171; J, 
 192. 
 
 optically illustrated, M, 313. 
 Invisible rays, see Light. 
 Ions, D, 1,370; E, 882. 
 
 unequal transfer of, during electrolysis, 
 
 1), u, 1115. 
 
 Iridescence, A, v, 499. 
 Iron fiddle, M, 132, 156. 
 
 meteoric, A, '61, 461, '66, 484. 
 
 passive state, J, 725. 
 
 ships, principle of flotation of, G, 140. 
 
 and steel, A, '63, 634. 
 
 why stronger than wood, G, 29. 
 Irradiation of light, see Light. 
 Isochimenal lines, B, 570; J, 866. 
 Isochronism of pendulum, E, 80. 
 
 vibrations, E, 303; 
 
 F, 80, 89; H, 398. 
 Isoclinical lines, A, xi, 64; E, 889; 
 
 F, 159; J, 691. 
 Isodynamic lines, A, xi, 64; E, 891; 
 
 E, 796; F, 161; J, 594. 
 Isogeothermic lines, J, 866. 
 Isogonalic lines, A, xi, 64; E, 884; 
 
 E, 789; J, 5S5. 
 Isologous groups, D, in, 429, and table, 
 
 433. 
 
 Isomerism, A, ix, 635; D, H, 653. 
 Isomorphism, A, v, 42, ix, 638 ; D, i, 
 
 108; E, 98. 
 
 aid of, in fixing equivalents, D, n, 1153. 
 Isomorphous bodies, rotation of, D, n, 
 
 718. 
 
 Isomorphous bodies, table of, D, I, 110- 
 
 Isotheral lines, J, 866. 
 
 Isothermal lines, A, ix, 638; B, 567; 
 
 E, 950; F, 379; 
 
 H, 399; J, 866. 
 run north and south 
 
 in England, H, 399; 
 
 L, 193. 
 Isothermal zones, J, 840. 
 
 Jar, luminous, J, 667. 
 Jet, form of, J, 166. 
 
 height of, J, 164. 
 
 lateral, J, 164. 
 Jets of air, action of sound onj M, 243. 
 
 of water, E, 225. 
 Joule's equivalent, M, 35. 
 
 experiments on heat, E, 760, 761. 
 
 Kaleidescope, A, x, 95; E, 741; E, 
 
 424; G, 307; H, 405; J, 431; N, 
 
 227. 
 Kaleidophone, H, 405; J, 525; M, 132, 
 
 156. 
 
 Kalychromatics, E, 464. 
 Kathode, see Anode, J, 719. 
 Keeper of magnet, D, I, 268; J, 603. 
 Key note, G, 201. 
 
 of nature, E, 335. 
 Khamsin,. J, 836. 
 Kienmayer's amalgam, J, 636. 
 Kilogramme, origin and history of, C, 
 
 15; J, 11,95. 
 Kilogrammeter, J, 395. 
 Kilometre, E, 18. 
 Kite, how sustained, N, 30. 
 Knife edge, J, 47. 
 
 Lactometer, I, 104; J, 95. 
 Lamp, A, x,277; H, 406; J, 443. 
 
 Argand, A, n, 68, x, 278. 
 
 Bunsen's, L, 62. 
 
 Carcel, A, x, 278. 
 
 Davy's, see below, safety. 
 
 Doebereiner's, B, 146. 
 
 hydrogen, E. 354. 
 
 safety, A, x, 280; D, II, 636; H, 406; 
 L, 251. 
 
 solar, A, x, 279. 
 
 vapor, A, x, 279. 
 Land and water, distribution of, J, 868. 
 
61 
 
 Laud and sea breezes, D, 1, 196; L, 187. 
 Lanterns, Magic, see Magic lantern. 
 Laplace's correction of Newton's form- 
 ula for the velocity of sound, M, 28. 
 Larynx, B, 246; E, 470; E, 388; G, 
 
 203. 
 
 Latent heat, see Heat. 
 Lateral explosion, see Lightning, return 
 
 stroke. 
 
 Latitude, parallel of, J, 60. 
 Latour's experiments, J, 285. 
 Laughing, theory of the act, G, 205. 
 Law, E, 3 ; J, 2. 
 of cooling, E, 632. 
 cosine, J, 330. 
 
 criterion of the validity of a, C, 8. 
 Dulong and Petit, J, 374. 
 Latour, E, 692. 
 Lenz, J, 766. 
 
 Mariotte and Boyle's, A, xui, 412 ; 
 B, 128; C, 301; E, 343; E, 
 274; J, 131-136; N, 167. 
 universal gravitation, E, 59. 
 Ohm's, J, 702. 
 Pascal's, J, 71. 
 
 physical, what is a, C, 7, 300; G, 10. 
 Poggendorf s, J, 683. 
 Laws of acoustics determine specific 
 
 heat, E, 653. 
 Bernoulli's, E, 384. 
 of capillarity, E, 237-240. 
 
 electrical attraction,- E, 819-822. 
 
 induction, E, 829. 
 electro-chemical action, E, 890- 
 
 898. 
 
 dynamics, E, 902. 
 magnetism, E, .915. 
 falling bodies, E, 71-73. 
 fusion, E, 658; J, 263. 
 gaseous mixture, J, 139. 
 Ohm, E, 880. 
 radiation, J, 326. 
 solidification, E, 662. 
 storms, A, IX, 385; B, 588; E, 
 
 971; J, 837. 
 tenacity, E, 170. 
 torsion, E, 166. 
 vibrations, J, 414. 
 Lead tree (Arbor Saturni), J, 725. 
 Leaning towers, F, 70; G, 49; J, 44. 
 Lecoiite's sensitive flames, M, 230. 
 
 Leidenfrost's experiment, J, 303. 
 Length of undulation, J, 174. 
 
 units of English and French, C, 11, 
 
 14; J, 10. 
 Lens, the crystalline, A, VI, 115, and 
 
 xvi, 129; F, 354. 
 Lenses, A, x, 454, xn, 538; B, 274; D, 
 
 I, 130; G, 319; E, 754; E, 593; 
 
 E, 438; F, 290; H, 414; I, 294; 
 
 N, 235. 
 aberration of, E, 454; E, 767; F, 
 
 295. 
 achromatic, A, I, 72, xv, 352, 353; E, 
 
 466, 504, 508, 511; F, 306, 349; 
 
 G, 328; 1,322; J, 479; N, 242. 
 aplanatic, A, x, 455, xv, 354. 
 axes of, G, 321. 
 axis, secondary, J, 458. 
 classification of, I, 295. 
 Coddington, A, xi, 474; F, 348. 
 compound, E, 450. 
 combined, A, xi, 473, 475; E, 763. 
 concave, E, 761 ; E, 448 : I, 299, 
 
 305. 
 convex, B, 298; D, i, 130; E, 759: 
 
 E, 447; F, 294; 1,298,301. 
 definition of terms, I, 297. 
 determination of magnifying power, 
 
 F, 295. 
 
 of diamond and other gems, A, xi, 473. 
 
 double convex, E, 759. 
 
 echelon, J, 500. 
 
 field or field glass, J, 490. 
 
 focal distance of, G, 321. 
 
 foci, E, 447-450; E, 762; F, 291, 
 
 292; J, 457, 455, 459, 462. 
 conjugate, I, 299. 
 compound, E, 450. 
 concave, E, 448; N, 238. 
 convex, E, 447. 
 principles of, E, 445. 
 rules for finding, E, 762 ; E, 
 
 449; F, 292. 
 
 Fresnel, E, 828; J, 507. 
 images formed by, E, 766 ; E, 453 ; 
 
 F, 294; N, 237. 
 
 meniscus, B, 275; F, 290; J, 99. 
 magnifying power of, E, 803; F, 294; 
 
 how determined, F, 295. 
 optical centre of, E, 765 ; E, 452 ; 
 J, 458; N, 236. 
 
62 
 
 Lenses, plano-convex, E, 760. 
 
 re fraction of oblique rays by, E, 451. 
 
 sound by, M, 20. 
 spherical aberration of, E, 767; F, 
 
 295. 
 
 Stanhope, A, xi, 474. 
 sulphide of carbon, A, xv, 355. 
 Wollaston's doublet, F, 349. 
 Leroy's dynamometer, E, 37. 
 Leslie's experiment, J, 289. 
 
 thermometer, see Thermometer. 
 Level, A, x, 480; G, 53. 
 
 spirit, E, 256; H, 422; 1, 86; J, 82; 
 
 G, 137. 
 
 surface, J, 42; N, 82, 128. 
 water, E, 255; I, 87; J, 81. 
 Levelling staff, J, 82. 
 Lever, A, xi, 327; B, 54; C, 97, 98; E, 
 198; E, 113; F, 92, 95; G, 94; 
 H, 423; 1,34; J, 23; N, 42-45. 
 applications of, E, 201; E, 115. 
 arms of, C, 98; G, 93. 
 conditions of equilibrium of, C, 98; F, 
 
 96; G, 94; 1,35. 
 
 compound, E, 200; G, 9; disad- 
 vantages of, G, 97. 
 kinds of, G, 93; 1,37. 
 modification of the, F, 95. 
 momentum of long arm of, in action, 
 
 F, 95. 
 
 three kinds of, C, 97. 
 theory of the, C, 97. 
 Leverage, A, xi, 327 ; C, 100. 
 Levers in the animal economy, F, 101. 
 Lewis, N, 63. 
 
 Leyden jar, A, vn, 63, xi, 71, xv, 344; 
 B, 393; D, I, 291; E, 
 945; E,847; F, 194; G, 
 382; I, 410; J, 653-661; 
 N, 295-299. 
 discharge of, F, 195. 
 
 not single but 
 serial, A, xi, 
 71. 
 
 electricity in, E, 946. 
 manner of charging, F, 195. 
 residual charge in, D, I, 299 ; 
 
 F, 197. 
 
 vacuum, F, 200. 
 
 Life of the higher animals, in what it 
 consists, K, 432; E, 10. 
 
 Life boats, how prevented from sinking, 
 
 G, 147. 
 
 Lifting a weight, A, xi, 319. 
 Light, A, x, 514; B, 252; E, 718; E, 
 
 398; G, 292; H, 425; 1,259. 
 aberration of, A, i, 34; F, 278. 
 
 chromatic, A, x, 455, xn, 
 539, XV, 349; E, 777; E, 
 465; F, 305; I, 321; J, 
 475; N, 241. 
 
 spherical, A, xv, 349, 353; 
 B, 264; E, 768; E, 
 455 ;F, 296; G, 329; H,2; 
 J, 441, 462; N, 238. 
 absorption of, A, x, 516; D, I, 135; E, 
 725; F, 301; G, 300; I, 262; K, 
 139; in Fresnel's lenses, A, vii, 
 754. 
 
 action of colored vapors on, D, i, 137. 
 eye on, E, 780; E, 469. 
 on silver salts, F, 387. 
 affects all matter, K, 115. 
 amount reflected, A, xv, 356; E, 
 
 407. 
 
 increases with the 
 angle of incidence 
 A, xii, 537 ; E, 
 726. 
 
 by mirrors of vari- 
 ous substances, 
 A, xv, 356. 
 analogy of, and heat, E, 591; E, 
 
 765. 
 
 analysis of, see decomposition of. 
 artificial, A, '62, 520, '63, 512; D, I, 
 
 135; E, 768. 
 colored, F, 299. 
 beams of, A, x, 515, 518; E, 720; I, 
 
 262. 
 
 chemical action of, A, xni, 287; D, 
 I, 115, II, 1133; F, 305, 387; K, 
 111. 
 color of, corresponds to pitch of sound, 
 
 L, 272. 
 depends on temperature, E, 
 
 768. 
 
 colored, action of crystals on, F, 317. 
 polarization of, see below, po- 
 larization. 
 
 conversion of, into chemical force, A, 
 x, 516. 
 
63 
 
 Light, conversion of, into electricity, A, 
 
 x, 516; heat, A, x, 516. 
 corpuscular theory of, A, x, 517; G, 
 
 293; H,426. 
 
 decomposition of, A, xn, 539; B, 287; 
 E, 769 ; E, 456, 458 ; G, 325 ; J, 
 464 ;'N, 239. 
 
 deoxidizing action of, D, n, 1133. 
 depolarized, modes of analyzing, F, 
 
 332. 
 
 developed by compression of air, L, 43. 
 crystallization, D, I, 117 ; 
 
 E, 89. 
 
 friction of quartz, L, 23. 
 heating solids, A, x, 514; 
 
 D, i, 116. 
 
 diffracted, fringes produced by, F, 308 ? 
 diffraction of, A, vi, 470 ; E, 839 ; 
 E, 532; F, 308; H, 173; J, 41T, 
 545; N, 262. 
 
 diffused, D, I, 126; E, 743; E, 410. 
 diminution of, with distance, laws of, 
 
 D, I, 123; L, 298. 
 
 dispersion of, A, x, 516, xn, 539; E, 
 725; E, 406; F, 301; H, 429; J, 
 449; N, 241. 
 
 dispersive power of bodies for, A, xv, 
 352; D, I, 135; 
 F, 302; J, 465. 
 diamond, A, vi, 442. 
 divergence of rays of, G, 296. 
 Drummond's, A, vi, 629. 
 duration of impression, B, 309. 
 electric, see Electric light, 
 elliptical polai'ization, see below, po- 
 larization, 
 emission of, A, x, 515; E, 721; F, 
 
 280. 
 
 theory of, L, 263. 
 emitted from all visible objects, E, 
 
 721; F, 280. 
 during crystallization, etc., 
 
 see above, developed, 
 epipolic dispersion of, A, VH, 575; E, 
 
 846; F, 302. 
 
 extinction of, A, x, 515, 516. 
 of flames, diminished by the rarefac- 
 tion of air, L, 64. 
 
 function of, in organization, K, 415. 
 of gas diminished by mixture with 
 air, L, 62. 
 
 Light and heat, analogies between, E, 
 
 590, 591. 
 
 Herschellian rays, J, 344. 
 homogenous, J, 469. 
 Huygen's theory of, F, 275 ; L, 263. 
 illuminating power of, N, 224. 
 image by, from small holes, E, 
 
 730. 
 
 index of refraction of, see below, re- 
 fraction of, index, 
 inflection of, F, 308. 
 influence of the recipient surface up- 
 on, K, 120. 
 upon vegetation, D, n, 481 ; 
 
 1133. 
 
 intensity of, A, x, 517; B, 256; E, 
 731, 732, 742,775; E, 
 413,463; F, 775; G, 
 297; 1,265; J, 422, 431; 
 N, 223. 
 
 diminishes as the square 
 of the distance, A, x, 
 517; B, 256; E, 731; 
 F, 279. 
 
 rays of, E, 775. 
 reflected, E, 742. 
 interception of, by air, A, x, 515. 
 
 water, A, x, 515. 
 
 interference of, B, 330; D, i, 143; E, 
 
 834; E, 527, 
 
 529; F, 306, 307; 
 
 G, 339; J, 542,545. 
 
 Fresnel's experiments 
 
 on, F,*307. 
 produces darkness, D, 
 
 i, 143. 
 
 internal reflection of, E, 727. 
 irradiation of, J, 525. 
 of lamps due to what, L, 60-62. 
 latent, A, xiv, 173: K, 41, 348. 
 lavender rays (of Herschel), F, 299. 
 law of sines, F, 286. 
 length of waves of colored, E, 531 ; 
 
 F, 299. 
 loss of, by absorption, K, 139. 
 
 in passing 
 through Fres- 
 nel's lenses, 
 A, vii, 754. 
 
 from magnesium in burning, A, xi, 61. 
 magnetism influences, E, 919. 
 
64 
 
 Light, measurement of, A. x, 517, xm, 
 290; compare Photometer and 
 Photometry. 
 
 media for, D, i, 127; I, 261, 292. . 
 modifications of, F, 280. 
 molecular changes, K, 130. 
 monochromatic, J, 469. 
 moves in straight lines, G, 295. 
 is motion of ordinary matter, K, 
 
 130. 
 
 nature of, E, 718. 
 Newtonian theory of, A, x, 617; F, 
 
 275. 
 non-luminous bodies made invisible 
 
 by, G, 301. 
 number of impulses involved in the 
 
 perception of light, L, 272. 
 oblique pencils of, transmitted through 
 
 lenses, E, 764. 
 opacity of bromine to, L, 366. 
 ordinary and extraordinary ray, law 
 
 of the rapidity of, F, 316. 
 oscillatory theory of, A, x, 518. 
 parathermic rays of, F, 394. 
 passage of, through different media, E, 
 
 758. 
 
 narrow fissures, 
 phenomena of 
 its, F, 309. 
 
 pencils of, E, 720; 1,262. 
 plane of polarization of, rotated by 
 
 crystals, C, 162, 167. 
 
 polarization of, B, 337; D, I, 149; E, 
 
 847; H,590; K, 110. 
 
 by absorption, A, xm, 
 
 439; E,851; 
 
 E, 645; F, 
 319. 
 
 in tourmaline, 
 F, 319. 
 
 by the atmos- 
 phere, E, 
 866; E, 
 561; F, 325. 
 
 by bundles of 
 glass plates, 
 D, I, 154; 
 
 F, 323, H, 
 592. 
 
 Light, polarization of circular, D, 1, 158; 
 ,861,864; 
 F, 326, 336, 
 349; H, 115, 
 695; J, 564; 
 Bioton,F, 
 341 ; con- 
 ditions for, 
 F, 336. 
 
 d e v e lopment 
 of the, by 
 e 1 e c tricity 
 and magnet- 
 ism, F, 339; 
 
 by dif- 
 ferent flu- 
 ids, F, 341; 
 
 formula 
 for, F, 349; 
 
 Fresnel's 
 experiments 
 on, F, 336; 
 
 of homo- 
 g e n e ou s 
 light, F, 338; 
 
 mode of 
 pro ducing, 
 F, 336; 
 m o 1 e c ular 
 force of, F, 
 340; -- of 
 quartz, D, I, 
 158; F, 337; 
 
 by sugar, 
 F. 341;-by 
 turpentine, 
 D, I, 158. 
 
 of colored circular, D, 1, 158 ; 
 
 E, 861; F, 326. 
 by compression, E, 864. 
 methods of effecting the, 
 
 F, 318. 
 
 by dispersion 
 of part of 
 the light, 
 A, xm, 439 
 through 
 agate, F, 
 319. 
 
65 
 
 N- 
 
 polarization of, by absorption by 
 double refrac- 
 tion, A, xm, 
 438; D, I, 150; 
 E, 858. 
 
 elliptic, A, xm, 
 439; F, 342; H, 
 596; angles 
 for, F, 343; 
 produced by 
 metallic reflec- 
 tion, F, 342. 
 
 by heat, E, 864. 
 
 homogeneous, F, 
 325. 
 
 by Iceland spar, 
 D, i, 150. 
 
 magnetic, D, i, 
 160, 414; E, 
 919; F, 339. 
 
 by Nicol's prism, 
 
 D, i, 159; F, 
 319; J, 555. 
 
 partial, E, 855 ; 
 
 E, 549; F, 
 323. 
 
 plane of the, D, i, 
 152. 
 
 reflection, A, 
 xm, 439; D, I, 
 154; E, 852; 
 
 F, 320. 
 refraction, A, 
 
 <>v ^ x,515. 
 
 through 
 glass 
 p lates, 
 F, 323 ; 
 H,592; 
 Ice- 
 1 a n d 
 spar, 
 F,319; 
 E, 853. 
 rotatory, A, xm, 
 
 440; E, 862. 
 by successive re- 
 fraction, E, 
 854. 
 
 .- 
 
 Light, polarization of, by tourmaline, D, 
 I, 150; F, 
 319. 
 transmission, 
 
 D, i, 154. 
 
 polarized, B, 337; D, I, 149; E, 847; 
 E, 545; F, 318; H, 590; 
 G, 341 ; J, 538, et seq. ; K, 
 110. Compare Light, po- 
 larization of. 
 action of sugar upon, D, I, 
 
 158, and in, 61. 
 analysis of, F, 332 ; J, 574. 
 ferment by, D, 
 
 in, 108. 
 
 analyzing plate for, D, i, 154. 
 applications of, E, 868; E, 
 
 563. 
 
 Brewster's law of, F, 324. 
 colors of, D, i, 155; E, 555; 
 
 E, 863; F, 327, 
 329, 366 ;J, 567-570, 
 
 exhibited by selenite, 
 
 F, 366; by mica, 
 F, 327. 
 
 produced in, D, i, 155 ; 
 
 F, 325; are always 
 
 com plementary, 
 
 F, 327 ; cause of 
 
 the, F, 327. 
 
 deviation of planes of, F, 338. 
 d i ft' e r ence from common 
 
 light, D, i, 153. 
 by dispersion, A, xm, 439 ; 
 
 F, 319. 
 
 double refraction, A, xm, 
 438; D,I,150; E,858; 
 E, 552 ; J, 549. 
 elliptic, A, xm, 439 ; F, 342 ; 
 
 H, 596; J, 566, 569. 
 extinction of by glass, agate 
 
 and tourmaline, F, 323. 
 general properties of, F, 321. 
 by heat, E. 864; E, 559. 
 Iceland spar, D, i, 150. 
 internal refraction, F, 325. 
 interference of, F, 326. 
 by metallic reflection, F, 342. 
 law of Brewster, F, 324. 
 
66 
 
 Light, polarized by Nicol's prism, D, i, 
 
 169 ;F, 319; J, 555. 
 position of planes after 
 
 refraction, F, 319. 
 presence of, in common 
 
 daylight, F, 325. 
 by reflection, A, xm, 
 439; D,i,154; E, 
 852; E, 546; F, 
 320; J, 560. 
 refraction, A, x, 615 ; 
 E, 853 ;E, 547, 
 648; F, 323; H, 
 592 J, 551. 
 
 rings of color in, D, 1, 155 ; 
 E,863; 
 E668; 
 F, 328- 
 330. 
 
 calc spar, 
 D,i,156. 
 exhibited by 
 ft cone of 
 rays, F, 
 828; by 
 homogene- 
 ous light, 
 F, 330; 
 in biaxial 
 crystals, F, 
 330; in 
 selenite, F, 
 366. 
 rotatory, A, xm, 440; E, 
 
 862; E, 666. 
 by tourmaline, D, 1, 160; F, 
 
 319. 
 
 transmission, D, I, 164. 
 vibratory bars examined by, 
 
 M, 168. 
 polarizing angle, J, 511. 
 
 instruments, E, 860 ; E, 
 
 664; J, 652. 
 
 power of agate, F, 319; 
 of organic liq- 
 uids, F, 340- 
 342. 
 
 sugar, F, 341; 
 of tourmaline, 
 D, I, 150; F, 
 319. 
 
 Light, prismatic decomposition of, F, 
 
 297. 
 refraction of, D, i, 130, 
 
 133. 
 
 produces the other forces, K, 116. 
 is produced by animals, D, i, 117. 
 properties of, E, 725 ; E, 406, 460. 
 is propagated in straight lines, A, x, 
 515; by means of waves or undu- 
 lations, A, x, 618. 
 
 propagation of, A, x, 515, 618, xin, 
 
 437; E, 722; E, 
 
 642; 0,296; J,416, 
 
 448; L,264; N,222, 
 
 in a homogeneous 
 
 medium, E, 722. 
 and sensation of, L, 264. 
 radiation of, A, x, 616. 
 rays of, A, x, 616, 618; E, 720; E, 
 401; F, 280; G, 296; 1,262; 
 J, 416; N, 222. 
 actinic or chemical, A, x, 518; 
 
 D, i, 139, IT, 1145. 
 calorific, A, x, 618. 
 ordinary and extraordinary, F, 314. 
 refrangibility of, A, x, 518. 
 are rendered parallel by convex 
 
 lens, A, vn, 764. 
 
 recom position of, B, 287; E, 770; E, 
 457; F, 298; I, 311; J, 447; N, 
 241. 
 
 reflection of, A, x, 515, xn, 536; B^ 
 258; D, I, 125; E, 
 725; E, 406; F, 281; 
 G, 301; H, 427; 1,267; 
 J, 426-443; L, 275; N, 
 224 ; compare Mirrors, 
 influence of recipient 
 
 surface on, K, 120. 
 internal, E, 727; E, 
 
 408; F, 288. 
 irregular, E, 743 ; E, 
 
 410; J, 431. 
 
 laws of, A, xii, 537 ; E, 
 726; G, 71; I, 269; J, 
 333 ; N, 225. 
 by parabolic mirrors, L, 
 
 279. 
 
 the quantity varies with 
 the angle, F, 281; G, 
 305. 
 
67 
 
 Light, reflection of, by transparent bod- 
 ies, I, 274. 
 specular, J, 431. 
 total, D, I, 130; E, 
 728; E, 409; G, 
 316; N, 234. 
 
 refraction of, A, x, 515, xn, 537 ; B, 
 270; D, I, 127, 128; 
 
 E, 725; E, 406; 
 
 F, 286; G, 312, 317; 
 H, 427; I, 283; J, 184, 
 444-447; compare 
 Lenses. 
 
 atmospheric, E, 842; 
 
 G, 314. 
 
 by bisulphide of carbon, 
 
 A, xv, 355. 
 from dense, through rare 
 
 media. F, 286. 
 
 of, double, D, i, 147; E, 
 856; E, 550; F, 314; G, 
 340; J, 538, 542.- by Ice- 
 land spar, D, I, 147; F, 
 315, 328; axes of, F, 315; 
 lines of, F, 315; ordinary 
 and extraordinary rays of, 
 D, I, 148; F, 314,315; 
 phenomena of, F, 314. 
 of, experimental proofs of 
 
 the, I, 285. 
 
 index of, A, vi, 442 ; D, 
 I, 129-133; E, 757; 
 E, 440; G, 316; F, 
 287-303; I, 285; J, 
 445, 451- (table) 453; 
 for ordinary and ex- 
 traordinary rays, F, 
 314; ratio of, to an- 
 gle of polarization, F, 
 324; to velocity of 
 undulations, F, 288. 
 laws of, I, 284. 
 limit to the, F, 288. 
 by liquids, A, v, 579. 
 media bounded by 
 parallel surfaces, 
 F, 289. 
 
 prisms, E, 756; F, 
 290; compare 
 Prisms. 
 
 Light, refraction of, some effects of the 
 
 1, 287. 
 
 by structures of the 
 eye, F, 354; 
 by spheres, F, 
 291. 
 
 two media, F, 
 287; bound- 
 ed by curves, 
 F, 288. 
 refractive indices of colored rays of, 
 
 F, 298. 
 
 power of bodies for, D, i, 
 128; F, 303; I, 
 285 ; table of, 
 D, i, 129, 133. 
 the diamond in- 
 creased by heat, 
 A, vi, 442. 
 double of various 
 
 bodies, F, 315. 
 of oxygen, D, I, 129; 
 of tabasheer, F, 
 291. 
 refrangibility, change in, D, i, 134. 
 
 of colored rays, F, 298. 
 relation of bodies to, E, 719. 
 
 to the vital forces of plants 
 and animals, K, 401, 
 420. 
 
 scattering of, D, i, 126. 
 action of, on silver salts, F, 387. 
 and sound, analogies of, K, 126; M, 
 
 13, 20. 
 
 of sun and stars, A, '63, 151. 
 sources of, E, 399; G, 294; I, 260. 
 spherical aberration of, see above, 
 
 aberration of. 
 
 theories of, A, x, 517; D, i, 118; E, 
 718, 724; E, 398, 405; F, 275, 
 296; H, 426; I, 259; J, 469; L, 
 263, 23; M, 22; N, 221, 258; total 
 reflection, see Light, reflection of; 
 transmission of, see Light, prop- 
 agation of. 
 
 three principles contained in, G, 344. 
 undulations of, D, I, 122, 142; L, 300. 
 frequency of the in 
 different colors, D, 
 i, 142. 
 
68 
 
 Light, undulations of, length of the, J, 
 
 173. 
 mechanism of the, 
 
 D, i, 122. 
 
 transversal, L, 300. 
 undulatory hypothesis of, A, x, 518; 
 
 D, i, 118; F, 275; G, 293; L, 263. 
 unpolarized, F, 275. 
 
 action of, on vapors, A, '68, 102. 
 velocity of, A, x, 517; D, I, 141; E, 
 723, 838; E, 404; F, 
 278, 288; G, 298, 299; 
 H, 430; I, 263; J, 413- 
 422. 
 Fizeau's experiments, J, 
 
 422. 
 Fouca ult's, E, 723; E, 
 
 404; J, 419. 
 influenced by refraction, 
 
 F, 288. 
 variable in different media, 
 
 D, i, 141; F, 288. 
 waves of colored, F, 299. 
 voltaic, D, i, 336; of voltaic arc, 
 
 cause of, K, 88. 
 waves of, L, 272; vibrations of, A, 
 
 xm, 290; G, 339. 
 white, composition and decomposition 
 
 of, B, 287; G, 326. 
 
 Young's theory of, L, 23; his estab- 
 lishment of the undulation theory, 
 L, 263; F, 275. 
 
 Lighthouses, A, MI, 754, x, 618; E, 
 829, 830; E, 522, 523; I, 307; J, 
 507. 
 
 Fresnel's system in, A, vii, 754. 
 system of lenses in, A, vii, 764. 
 
 parabolic reflectors in, A, 
 
 vii, 753. 
 
 Lights, sea, E, 829. 
 revolving, E, 830. 
 Lightning, A, x, 526; B, 390; D, I, 310; 
 
 E, 1089; E, 990, 991; F, 207; 
 G, 392; H, 431; I, 423; J, 857; N, 
 311. 
 
 classes of, see below, varieties of. 
 
 conductors of, B, 389, 398, 621 ; D, I, 
 311; J, 858; see Electricity, con- 
 ductors of. 
 
 effects of, B, 619; G, 396; I, 424. 
 
 its explosive power, D, i, 311. 
 
 Lightning, identical with electricity, D, 
 
 1,310; I, 421. 
 
 menus of safety from, T, 425. 
 photogi-aphs, A, xiv, 174. 
 return stroke of, E, 1091; E, 992; 
 
 F, 203; I, 426; N, 311. 
 rods, A, x, 527; E, 1094; E, 993; 
 F, 208; G, 394, 395; I, 427; J, 
 858; N, 312; protective power of, 
 E, 1095. 
 
 varieties of, G, 393; E, 1090. 
 Limits of elasticity, E, 168. 
 
 magnitude, E, 103; E, 
 
 173. 
 
 viability, B, 309. 
 Line of direction, A, xi, 321; G, 49; N, 
 
 36. 
 
 sight, J, 492. 
 vertical, G, 63. 
 Lines of spectrum, J, 471. 
 Liquation, D, n, 1029. 
 Liquefaction, E, 655; G, 237. 
 a cooling process, D, I, 216. 
 crystallization by, E, 80. 
 of gases (table), E, 664; E, app., 
 
 table XX. 688; J, 296-299. 
 ice by friction, G, 206, L, 40, et 
 
 seq. 
 
 pressure, L, 121, 148, 328. 
 vapors, E 646 ; E, 685. 
 Liquid columns balance by pressure, 
 not by weight, A, ix, 413; G, 128. 
 condition of matter, the, C, 117; F, 
 
 42, 51; L, 76. 
 
 surfaces, E, 234; G, 133; N, 127. 
 veins, action of sound on, M, 247. 
 
 constitution of, E, 277 ; E, 
 
 222. 
 contractions of, A, ix, 415; E, 
 
 278. 
 
 as sound reagents, M, 250. 
 Liquids, C, 117: E, 186; F, 42, 51; J, 
 
 9, 69; L, 75; G, 23. 
 absorption of, by porous solids, C, 363. 
 buoyancy of, C, 235-247. 
 calorific transmission of, L, 313 (ta- 
 ble). 
 
 centre of pressure of, C, 220. 
 characteristic properties of, C, 215. 
 compressibility of, A, v, 579; B, 115; 
 C, 217,215, 114; D, I, 34: N, 119. 
 
69 
 
 Liquids, conduction of heat by, B, 548 ; 
 C, 657; D, I, 188; E, 278; E, 
 619; 0, 217. 
 contracted vein in, see above, Liquid 
 
 veins, 
 convection of heat by, D, I, 191 ; E, 
 
 568; E, 627. 
 how cooled, G, 222. 
 currents, latent, reaction of, F, 130. 
 curves of expansion of, E, 541. 
 delivery of, through pipes, see below, 
 
 discharge of. 
 
 diamagnetism of, D, I, 417; J, 805. 
 diffusion of, A, xvi, 729; C, 384; D, I, 
 
 67-70; F, 64; J, 104. 
 apparatus for measuring 
 
 the, C, 384; D, i, 68. 
 chemical decomposition 
 
 by means of, D, I, 70. 
 illustrations of the, C, 384. 
 influence of temperature 
 
 upon, D, i, 70. 
 is proportional to strength 
 
 of solution, D, I, 69. 
 laws of the, 0,385; D, I, 
 
 68, et seq. 
 
 direction of pressure of, C, 219. 
 discharge of, A, ix, 415. xin, 413; C, 
 273; D, i, 77, tables; 
 E, 272-281; G, 149; 
 N, 144. 
 appearance of surface 
 
 during the, E, 272. 
 means of obtaining a 
 
 constant, E, 276. 
 efflux of, D, i, 77, (tables). 
 elasticity of, A, v, 579; B, 115; C, 
 
 115, 215; E, 188. 
 
 equilibrium of, conditions of the, B, 
 80; C, 228-232; E, 
 249-250; E, 199, 
 200; I, 82-85. 
 in communicating ves- 
 sels, I, 83. 
 
 of different densities 
 in communicating 
 vessels, E, 250; I, 
 84. 
 
 in same vessels, E, 
 249; heterogene- 
 ous, I, 85. 
 
 Liquids, escape of, through capillary- 
 tubes, E, 281; long tubes, A, 
 IX, 415; E, 280; from orifices, 
 A, ix, 415 ; short tubes, A, ix, 
 415; E, 279. 
 
 expansion of, C, 507; D, I, 168, tables, 
 I, 166 ; E, 536, 539, ta- 
 ble; E, 597-603, appen- 
 dix tables XVI-XIX; G, 
 229; L, 91; N, 201. 
 above boiling, E, 602. 
 friction of, against liquids, A, ix, 416; 
 F, 132; G, 124; against solids, A, 
 
 ix, 416. 
 
 frothing of, G, 180. 
 lateral pressure of, B, 185; F, 130; I, 
 
 76 
 
 level surface of, E, 248. 
 mechanical condition of, C, 215. 
 pressure of, A, ix, 412; 0,219-232; 
 E, 238,271; E, 189- 
 193; G, 125; I, 75-79; 
 N, 120. 
 
 on bottom of a vessel is 
 independent of its 
 shape, I, 78. 
 containing vessels, A, 
 ix, 413; C, 224-227; 
 E, 271. 
 
 is due to gravity, i. e., to 
 the weight of the liq- 
 uid, C, 223; I, 75. 
 formula for, C, 219, 227, 
 
 232. 
 Pascal's experiments on, 
 
 1,79. 
 principle of Archimedes, 
 
 see Archimedes, 
 is proportional to area of 
 receiving surface, A, 
 ix, 412. 
 
 is transmitted in all di- 
 rections, A, ix, 412 ; E, 
 238; I, 74; upwards, 
 I, 77. 
 
 properties of, C, 215 ; I, 73. 
 resistance of, N, 146. 
 refraction of light by, A, v, 579. 
 sound transmitted by, M, 79; N, 183. 
 
 velocity of, in, E, 427. 
 Specific gravity of, see Specific gravity. 
 
70 
 
 Liquids, some are susceptible of mag- 
 netic polarization, D, I, 415, 417. 
 spheroidal state, see Spheroidal state, 
 transmit forces, F, 105. 
 
 pressure in all directions, A, 
 IX, 412; C, 218; E, 238; 
 E, 189-192; G, 125; I, 
 74: N, 120. 
 
 vapors of, tension, J, 278. 
 vaporize instantly into a vacuum, A, 
 
 xv, 44. 
 
 vaporization of, is retarded by the at- 
 mosphere, A, xv, 44. 
 velocity of discharge of from orifices, 
 
 A. xin, 413. 
 sound in, E, 427. 
 volatile and fixed, J, 269. 
 volume of, C, 666. 
 when do they wet a surface, G, 30. 
 will not flow from a tight cask, G, 
 
 179. 
 Lissajous's experiments, J, 217-222; 
 
 M, 60. 
 
 Litre, C, 17; J, 11. 
 Living force, see Vis Viva. 
 Loadstone, D, I, 264, II, 895; E, 869; 
 E, 774; G, pp. 416,417; J, 676; 
 N, 264. 
 
 Lock, Bramah's, A, in, 634. 
 Locks in canals, A, ; G, 137. 
 Locomotive, see Steam engine. 
 Longsightedness, A, xvi, 129; B, 303; 
 E, 795; E, 486; J, 518, 527; 
 G, 352. 
 
 Looking glasses, see Mirrors. 
 Looming, see Mirage. 
 Loops and nodes, J, 203. 
 Lubricants, A, vn, 758, x, 708; L, 21; 
 use of, on wheels and axles, L, 
 21. 
 
 Luminosity, secondary, A, x, 516. 
 Luminous bodies, F, 278 ; J, 415. 
 jar, J, 667. 
 pane, J, 666. 
 point, B, 252. 
 rays of spectrum, D, I, 133. 
 
 wave lengths of, A, x, 518; E, 
 
 838; F, 299, table, 
 undulations of comparison be- 
 tween, and sonorous, 
 F, 307. 
 
 Luminous rays, interference of, D, x t 
 
 142; F, 306,307, 309. 
 tube, J, 666. 
 
 vibrations, nature of, E, 847, 838 
 (tables); transmission of, E, 848.' 
 Lustre, metallic, D, n, 665. 
 
 Machinery, elements of, A, xi, 325. 
 Machine, Atwood's, see Atwood's ma- 
 chine. 
 Machines, A, xi, 327; E, 187,192- 
 
 197; E, 105-107; G, 90; H, 446; 
 
 I, 33-38; K, 79,214, 387; N, 41, 
 
 42, 64. 
 
 classification of, E, 197. 
 compared with the living system, K, 
 
 79. 
 
 diminish force, G, 90. 
 driving force of, K, 214, 387. 
 do not produce power, G, 90. 
 economy of, G, 91, 92, 94. 
 elements of, A, xi, 325; G, 93; N, 42. 
 equilibrium of, E, 192. 
 "loss in time and gain in power," 
 
 meaning of the expression, G, 93. 
 motion in, when, G, 92. 
 practical power necessary to main- 
 tain, A, xi, 328. 
 Utility of, E, 193. 
 when caught on a centre, G, 112. 
 Mackerel sky, J, 839. 
 Magdeburg hemispheres, B, 137; F, 
 
 127; G, 177; I, 110; J, 115; N, 
 
 158. 
 Magic lantern, A, xi, 56; B, 283, 320; 
 
 E, 822; E, 515; F, 347; G, 367; 
 
 I, 334; N, 252. 
 squares, E, 954; E, 852. 
 Magnetic attraction, D, I, 264; E, 
 
 780; E, 875; F, 212; G, 419; J, 
 
 595; N, 266. 
 
 axes of astatic needles cross, L, 33. 
 bars, action of electric currents on, F, 
 
 240. 
 
 battery, J, 602. 
 bodies, list of, D, I, 272, 417, 421; F, 
 
 168; 1,363. 
 
 curves, E, 872; E, 777. 
 declination, A, xi, 64 ; F, 157, et seq. ; 
 
 H, 354 or 468; I, 367; J, 586; N, 
 
 273-275. 
 
71 
 
 Magnetic deviation, quadrantal, J, 601. 
 dip, E, 791; N, 276. 
 equator, B, 359; D, I, 271; E, 886; 
 
 F, 159; N, 276. 
 field, D, I, 416. 
 
 apparent viscosity of, L, 49, 51. 
 figures, E, 873; E, 778. 
 fluids, B, 349; E, 880; I, 361; J, 
 
 578; N, 264-268. 
 force, F, 164; G, 418. 
 
 diminution of, by distance, B, 
 
 364. 
 distribution of, E, 871 ; E, 
 
 776; N, 264. 
 lines of, A, xi, 61; E, 894; E, 
 
 799; F, 153. 
 formulae, Ampere's, F, 241. 
 formula, Coulomb's, F, 164. 
 
 Eschenmaier's, F, 156. 
 inclination, A, ir, 64; F, 158, 160. 
 indications, theory of, F, 156. 
 induction, A, xi, 61; B, 493; D, I, 
 265; E, 878, 929; E, 783; F, 
 154 ; H, 451 ; J, 769 ; N, 266 ; G, 421. 
 influence, F, 168; J, 381; K, 145. 
 intensity, A, xi, 64: D, i, 269; E, 
 890; E, 795; F, 164; N, 278, 279. 
 iron (soft) made, G, 421; N, 331. 
 law (Krafft's), F, 160. 
 limit, J, 605. 
 
 machinery, see Magnetic electric ma- 
 chines, 
 meridian, B, 356; E, 883; E, 788; 
 
 F, 158; G, 425; I, 367; J, 584; N, 
 276. 
 
 needle, A, '68, 446; B, 359; E, 882, 
 E, 775, 787; F, 154; G, 423, 426; 
 action of the earth upon, F, 161 , 
 directive tendency of, E, 882; 
 variations of, E, 885 ; disturb- 
 ance of the, in auroral displays, E, 
 1042. 
 
 neutral line, J, 577. 
 
 observations, E 893 ; E, 798. 
 
 perturbations, see Magnetic storms, A, 
 xi, 65; J, 585, 286. 
 
 phantom, E, 872; E, 777. 
 
 polarity, D, i, 267; E, T76; F, 154; 
 
 G, 419. 
 
 poles, A, xi, 64; F, 154; J, 576-583; 
 N, 265, 277-279. 
 
 Magnetic poles of earth, F, 
 
 mutual action rtf, J, 577. 
 
 precise definition of x J 
 r > 
 
 579. 
 
 position, axial, D, I, 416; G/ 42J. 
 processes, F, 163. 
 properties assumed by wires conduct- 
 
 ing electricity, F, 243. 
 of metals, F, 162 ; of oxygen, D, I, 
 
 420; of salts, F, 162. 
 repulsion, see Magnetic attraction. 
 saturation, J, 602. 
 action of earth on solenoids, J, 739. 
 storms, A, xi, 66 ; D, I, 271 ; E, 1042 ; 
 
 F, 160; J, 585; N, 281. 
 cycle of the, corresponds with 
 that of the solar spots, A, 
 xi, 67. 
 theory, see above, law, and below, un- 
 
 der Magnetism. 
 
 variation chart, E, 883; E, 789. 
 variations, A, xi, 64; E, 788-790; 
 
 F, 160; G, 428; I, 367; J, 584-586; 
 
 diurnal and horary, F, 160. 
 Magnetics and diamagnetics, table, D, i, 
 
 421; E, 877; E, 782; F, 162, 
 
 167, 168. 
 Magnetism, A, xi, 61; D, i, 420; F, 
 
 162; G, 417; I, 358; J, 2, 576. 
 action of, on light, E, 1024. 
 Ampere's theory, B, 467; E, 908 ? 
 
 F, 251; 1,453-455. 
 memoria technica of, J, 697. 
 of all bodies which are conducting 
 
 the voltaic current, D, I, 318. 
 animal, A, I, 93; G, 418. 
 atmospheric, E, 895 ; E, 800. 
 coercive force of, I, 365. 
 by contact, E, 876. 
 of copper wire, cause of, L, 35. 
 definition of, I, 358. 
 developed by electric discharge, A, 
 
 vn, 63 ; in the vicinity of electric 
 
 currents, A, ix, 21; by galvanic 
 
 action, A, xi, 62, 67; H, 451; by 
 
 induced currents of ordinary elec- 
 
 tricity, A, xi, 69. 
 and diamagnetism, A, vi, 440, vn, 73, 
 
 xi, 63; D, i, 417-424; E, 641; E, 
 
 920; F, 166-168; G, 441; H, 168; 
 
 J, 805-807. 
 
72 
 
 Magnetism a directive force, D, i, 264; 
 
 E, 787; I, 366; K, 142. 
 distribution of, E, 776; J, 605. 
 of the earth, A, xi, 63 ; B, 361 ; D, I, 
 
 270; E, 887-896; E, 787, 792, 
 
 801; G, 422; H, 468; J, 593; N, 
 
 270-280, 338. 
 of the earth, action of, on the dipping 
 
 needle, E, 887; inductive power 
 
 of, E, 892; origin of, E, 896; 
 
 variation of intensity of, D, I, 
 
 271 ; amplitude of the diurnal 
 
 variations, B, 361 ; H, 475. 
 by electric discharge, A, vu, 63; J, 
 689. 
 
 electricity, A, xi, 62, 67 ; E, 904- 
 
 915; F, 240,249; G, 
 
 432; H, 451; J, 745; 
 
 N, 306. 
 
 induced, A, ix, 21, xi, 
 
 69. 
 
 of green silk, L, 35. 
 heat diminishes, D, I, 269; F, 165; H, 
 
 454. 
 
 impaired, E, 904; E, 808; N, 270. 
 by induced electric currents, F, 458. 
 induction of, A, xi, 61; F, 154; H, 451. 
 
 by currents, F, 249. 
 inductive power of the earth's, E, 
 
 892. 
 influence of, on light and heat, K, 145; 
 
 on matter, F, 168. 
 as an initiating force, K, 147. 
 intensity of, how determined, D, I, 269. 
 of nickel, F, 162. 
 
 in non-ferruginous bodies, E, 877. 
 and p;ir;im:i<inetism, see Magnetism 
 
 and diamagnetism. 
 a polar force, D, I, 264; G, 419. 
 retention of, by metals, F, 164. 
 static and dynamic, K, 149. 
 of steel by sun's rays, E, 903; E, 
 
 807. 
 
 terrestrial, see above, of the earth, 
 theories of, A, vu, 70; B, 467; E, 
 
 879; E, 908; F, 155, 251; G, 423; 
 
 1,453-455; J, 548; N, 333. 
 of iron vessels, J, 600. 
 what bodies susceptible of, D, I, 272, 
 
 417, 421. 
 
 Magnetism, why not available for driv- 
 ing machinery, G, 433. 
 Magnetization, D, i, 267, 384; E, 
 876; E, 781, 803, 912; F, 163; H, 
 452; I, 371; J, 689, et seg.; N, 272, 
 336. 
 is attended with molecular action, D, 
 
 i, 382. 
 
 Magnetized bodies, I, 363. 
 Magnetizing by terrestrial induction, I, 
 
 371 ; by friction, I, 372. 
 Magnets, A, xi, 61; E, 869; 1,358; 
 
 H, 451. 
 
 action of currents on, F, 240 ; I, 453 ; 
 
 J, 729-736, 801; N, 326-330. 
 
 upon currents, F, 243 ; I, 453 ; 
 
 J, 737, 738; N, 329. 
 rotating disc of metal upon, 
 D, i, 403; on suspended 
 rectangles, F, 247; on 
 wires conducting electric- 
 ity, F, 243. 
 
 anomalous, E, 874 ; E, 779. 
 armature, Siemen's, J, 786. 
 armatures, B, 351; G, 423; H, 39; I, 
 
 374; J, 603; N, 267. 
 artificial, G, 418, 423; E, 870; E, 
 775; J, 576; N, 264, 272; compare 
 .Magnetization. 
 broken, D, i, 266; F, 155; J, 580; N, 
 
 267. 
 
 bundles of, I, 374. 
 circumstances affecting value of, E, 
 
 898. 
 
 coercing power of, F, 164. 
 compound, E, 902 ; E, 806. 
 consecutive poles of, F, 162. 
 constitution of, F, 153. 
 declination of, F, 157; H, 468. 
 deviation of by electric currents, F, 
 
 240. 
 
 to deprive of their power, E, 904. 
 directive force of, I, 366. 
 distribution of force in, I, 359. 
 effects of fracture on, F, 155; D, i, 
 
 266 ; of heat on, F, 165. 
 electro, see Electro-magnetism. 
 Henry's, E, 1021. 
 
 horseshoe, G, 420; E, 900; E, 804; 
 F, 164. 
 
73 
 
 Magnets, inclination of, F, 158. 
 
 keeper of, use, D, i, 268; J, 603. 
 making of, F, 163. 
 
 natural. D, I, 264, II, 895 ; E, 869 ; E, 
 774; F, 153; G, 417; J, 576; N, 264. 
 optical effects, J, 804. 
 poles of, B, 347; F, 154; G, 418. 
 
 repulsion of bodies by both, 
 
 F, 165. 
 production of artificial, D, I, 267; F, 
 
 163; E, 897; H, 452. 
 rotation of, around a wire conducting 
 
 electricity, F, 244; G, 431. 
 by touch, E, 899. 
 are said to " traverse " when, G, 419. 
 steel, how made, G, 421. 
 variations of, self indicated, F, 160, 
 
 392. 
 Magneto-electric action, law of, D, i, 
 
 404; intensity of, F, 241. 
 apparatus, E, 1042; E, 938; J, 
 
 776. 
 currents of different orders, A, xi, 69; 
 
 F, 253. 
 
 induction, D, i, 397; E, 1037; F, 
 
 252-254. 
 machines, A, '64,489; B, 475; D, I, 
 
 405; E, 938; E, 1023; F, 260; 
 
 G, 433, 438; J, 781-790; K, 222; 
 N, 335. 
 
 shock, F, 254. 
 
 spark, F, 259. 
 
 Magneto-electricity, A, VH, 69, xi, 
 67; A, '64, 489; B, 470; D, I, 397; 
 F, 252; G, 429. 
 
 chemical effects of, D, i, 407 ; F, 257. 
 
 Faraday's discovery of, L, 50. 
 
 Joule's experiments upon, L, 86. 
 
 calorific effects of secondary currents 
 of, F, 254. 
 
 electrolysis by, F, 257. 
 
 induction of currents of, by perma- 
 nent magnets, F, 253 ; by tempo- 
 rary magnets, F, 253; of second- 
 ary currents bv electricity, F, 253; 
 by electro-mngr.ets, F, 253, by 
 magnets, F, 253; shock from sec- 
 ondary currents of, F, 254. 
 Magneto-optical properties of silico- 
 borate of lead, D, i, 414. 
 10 
 
 Magnifying glasses, compare Lenses; 
 B, 316; E, 802; E, 493; G, 324; 
 J, 481. 
 power, A, xi, 474; E, 803; E, 494; 
 
 J, 492. 
 
 measure of, J, 484, 490. 
 Magnitude, E, 13 ; G, 12 ; J, 4. 
 centre of, G, 45. 
 limits of, E, 103; E, 173. 
 Major chord, J, 192. 
 Malleable cast iron, D, u, 881. 
 Malleability, A, vi, 648; C, 205-208; 
 D, i, 54, n, 668; E, 174; G, 26; 
 J, 3, 67; I, 72. 
 
 and ductility (table of), D, n, 669. 
 order of, C, 207. 
 
 variations of, with temperature, G, 208. 
 Man, mechanical efficiency of a, A, 
 
 ix, 23. 
 
 power of a, A, xi, 327; E, 131. 
 works to best advantage when, A, xi, 
 
 327. 
 
 Manometers, A, xi, 152, xm, 412; B, 
 143, 201; D, I, 43; E, 345; E, 
 278; G, 88; I, 126; J, 136. 
 with compressed air, C, 310; E, 347; 
 
 E, 280; I, 127; J, 136. 
 free air, E, 346; E, 279; I, 
 
 126; J, 136. 
 
 metallic, Bourdon's, C, 189 ; see Ane- 
 roid Barometer. 
 
 Manometer, Regnault's, C, 308 ; J, 138. 
 Marcet's apparatus, C, 574; E, 635. 
 Mare's tails, J, 838. 
 Marriotte's flask, formula for, C, 323, 
 
 324; J, 169. 
 
 law, A, xm, 412; B, 128; C, 293, 
 301; D, I, 35; E, 343; E, 
 274 ; F, 125 ; G, pp. 166, 167 ; H, 
 488; I, 124; J, 131-136; N, 167. 
 departure from, A, xni, 412; C, 
 290, 299, 532, 586, 602; D, I, 
 36 note, 255; E, 656, 344. 
 experiments on, C, 290-295. 
 formula for. C, 287, 288. 
 history of, C, 290. 
 illustrations of, C, 288. 
 limits of, E, 344. 
 relation of, to the expansion of 
 gases, C, 532, 586. 
 
74 
 
 Marriotte's law, statement of, C, 287. 
 
 variations from, see above, de- 
 parture from, 
 receiver, N, 159. 
 tube, I, 124, J, 132. 
 Mass, A, xr, 318; B, 37; C, 18, 91; E, 
 
 41, 96; J, 10. 
 influence of, on affinity, see Chemical 
 
 affinity, 
 unit of, C, 91', 
 Masses, F, 510. 
 Mastics, A, iv, 641. 
 Mathematics, function of, in investiga- 
 tion, K, 377. 
 
 Matter, C, 3; K, 6; E, 1; G, 11; J, 1. 
 accessory or accidental properties of, 
 
 C, 10; E,21; E, 19; F, 62. 
 cause of changes in, G, 21. 
 compressibility of, see Compressibility, 
 density, see Specific gravity, and 
 
 Density. 
 
 divisibility, see Divisibility, 
 essential properties of, C, 10; E, 17; 
 E, 12; F, 50; G, 12; N, 
 16-18. 
 nature of, not understood, C, 
 
 3; K, 187. 
 
 expansibility of, C, 113. 
 forms of, E, 38; E, 15; F, 42, 61; 
 
 N, 14. 
 general laws of, C, 3 ; E, 6 ; E, $ 6 ; 
 
 G, 11. 
 indestructibility of, D, I, 10, II, 445; 
 
 E, 9; G, 18; K, 12; N, 15. 
 minute division of, E, 13, 14. 
 physical and chemical properties of, 
 
 C,3. 
 
 porosity of, illustrated, C, 110. 
 smallest quantity visible to the eye, 
 
 G, 14. 
 
 specific properties of, C, 3. 
 three states of, E, 38; F, 42, 51. 
 ultimate structure of, may never be 
 
 known, K, 187. 
 Matting, action of, in excluding frost, 
 
 G, 272. 
 
 Measures, see Weights. 
 3Ieasurers, stream, E, 284. 
 Measurements, barometrical, A, in, 
 659 ; compare Barometer. 
 
 Mechanical advantage, A, xi, 327. 
 equivalent of heat r see Heat, 
 force, see Force, 
 origin of solar heat, K, 276. 
 powers, the, see Mechanism, ele- 
 ments of. 
 
 problem, the modern, K, 212. 
 processes, force, amount, formerly and 
 now possessed in our sys- 
 tem, L, 443. 
 
 generation of heat by, L, 17 ; 
 see Heat, 
 theory of heat, see Heat, dynamical 
 
 theory of. 
 
 ralne of the change from steam to 
 liquid water, L, 163; from water 
 to ice, L, 164; of union of oxygen 
 and hydrogen, L, 163. 
 work, consumption of heat in, L, 26. 
 Mechanics, A, xi, 317; C, 32; I, 22; N, 
 
 21. 
 Mechanism, elements of, A, xi, 327; 
 
 F, 92; G, 93; N, 63. 
 of voice, E, 389. 
 Megascope, F, 346. 
 Melde's experiments on sonorous rip- 
 ples, M, 154. 
 vibrating 
 strings, M, 
 105. 
 Melloni's apparatus, E, 642. 
 
 researches, J, 341. 
 Melodeon, silent, A, '68, 463. 
 Melody, E, 448. 
 Melting point, C, 648. 
 
 of alloys, C, 550, 554. 
 lowered by pressure, A, 
 
 IX, 21 ; C, 550. 
 
 Memoria technica for magnetism, J, 697. 
 Meniscus, B, 275; C, 347, 349; G, 320; 
 
 compare Lens, 
 of barometer, E, 238; J, 123. 
 Mensuration, A, xi, 385. 
 Mental and vital forces, K, XXXII. 
 Mercurial rain, E, 24. 
 
 trough, see Pneumatic trough. 
 Mercury, column of, how measured, C, 
 
 280. 
 
 expansion of, J, 248. 
 freezing of, B, 535 ; J, 288, 299, 304. 
 
75 
 
 Meridian, G, 36 ; J, 10 ; measurements, 
 E, 91. 
 
 Metacentre, A, ix, 414; C, 244; E, 
 208; J, 87. 
 
 Metals, A, xi, 405, xv, 138; B, 452; C, 
 
 120; D, II, 665; E, 995; E, 
 
 180, 615; F, 164, 231; A, '61, 455, 
 
 '65, 539, '66, 480, '68, 464. 
 
 become fragile after repeated shocks, 
 
 A, xv, 138. 
 
 conducting power of, A, xi, 406; B, 
 
 452. 
 
 crystallization of, C, 120. 
 density of, A, xi, 405. 
 deposition of, upon others, E, 995 ; 
 
 F,231. 
 
 ductility of, A, xi, 406. 
 fatigue of, A, xv, 138. 
 fusible, J, 264. 
 galvanic action between, G, 415. 
 
 deposition of, F, 231. 
 general properties of, D, n, 665. 
 hardness of, A, xi, 406 
 magnetic properties of, F, 162. 
 malleability and ductility of, D, n, 
 
 668. 
 
 occlude hydrogen, A, '68, 100. 
 power of retaining magnetism, F, 164. 
 pulverulent condition of, D, n, 665. 
 the so-called "tamtam," J, 68. 
 tenacity of, A, xi, 406. 
 volatility of, D, n, 672. 
 Metamerism and metameric com- 
 pounds, A, ix, 635; D, u, 653. 
 Metamorphoses by chemical substitu- 
 tion, D, in, 44. 
 Metamorphosis, retrograde in animals, 
 
 K, 421. 
 
 Metaphysics in science, K, 360. 
 Meteoric iron, A, '61, 461, '68, 474. 
 phenomena, G, 288. 
 theory, of the sun's heat, see under 
 
 Heat. 
 Meteorites, A, '65, 544, and '66, 484; 
 
 B, 614; G, 288; K, 270. 
 heat generated by, K, 234. 
 probably rendered incandescent by 
 
 friction against air, L, 23. 
 .Meteorology, A, xi, 415: B, 555; C, 
 2S7: E, 946; G. 266: L, 401, et 
 .seq.\ A, '62.570. 
 
 Meteorology, absorption of aqueous va- 
 por applied to phenomena of, L, 
 
 401, et seq. 
 
 use of the barometer in, C, 287. 
 Meteors, A, xi, 412; A, '66, 484, '68, 
 
 474; B, 614; G, 289, 290. 
 amount of heat generated by collision 
 
 with the sun, L, 438. 
 electric, F, 209. 
 
 number of, seen in Boston, L, 436. 
 periodic and sporadic, A, xi, 414. 
 sun's light and heat kept up by, L, 58, 
 
 436, 437. 
 Metre, C, 14-17; D, i, 25, in, 809; N, 
 
 112; compare Weights and Meas- 
 ures, French. 
 
 an arbitrary measure, C, 16. 
 origin and history of, C, 14. 
 subdivisions of, C, 17. 
 Metric system, A, '66, 493. 
 Metronome, I, 63. 
 Micrometer, A, xi, 472, xv, 357; H, 
 
 497; J, 5, 491; N, 62. 
 Microscope, A, xi, 473; A, '64, 533; 
 
 E, 513; F, 346; G, 360, 361; H, 
 
 499; 1,331; J, 5. 
 aberration of glass cover of object 
 
 corrected, E, 818; E, 510. 
 achromatic, E, 816, 819; E, 513, 
 
 511, 508; F, 349. 
 Amicis, J, 485, 486. 
 Chevallier's, J, 486. 
 compound, A, xi, 475; B, 320; E, 
 
 805; E, 496; F, 348; G, 361; J, 
 
 479; I, 333; N, 253. 
 dissecting, of Raspail, E, 804; E, 
 
 495. 
 
 eye-pieces of, E, 809: E, 500, 512. 
 field of, J, 480. 
 
 mechanical arrangements of, E, 821. 
 object glasses, E, 508; E, 816. 
 photo-electric, J, 338; J, 506. 
 polarizing, F, 335. 
 powers of, J, 490. 
 reflecting, F, 352. 
 simple, A, XI, 473; B, 316; E, 804; 
 
 E, 495; F, 346; I, 331; J, 481; 
 
 N, 250. 
 solar. B, 319; E, 823; E. 516; F, 
 
 347; G, 368; J, 504; N, 251. 
 stand, E, 821; E, 514, 
 
76 
 
 Millimetre, E, 18; see Metre and 
 
 Weights. 
 Mines, explosion of, by electricity, J, 
 
 672, 708. 
 
 Mirage, A, xi, 562; E, 844; E, 540; 
 F, 289; G, 315; H, 802; 1,290; J, 
 447. 
 
 Mirror, Soemmering's, F, 348. 
 Mirrors, A, xiv, 832, xv, 351-356; B, 
 261; E, 682, 735; E, 415-41T; 
 F, 282; G, 303; H, 506; I, 270; J, 
 430. 
 
 aberration of, E, 753 ; E, 437. 
 burning, J, 334, 442; G, 308. 
 coating of, D, n, 931, 1031. 
 concave, B, 262; D, I, 127; F, 284, 
 345; G, 308; I, 275; J, 
 332, 437; N, 230. 
 and convex, B, 268; E, 744. 
 formation of images by, F, 284. 
 principal focus of, I, 276. 
 reflections from, F, 283. 
 conjugate, for the reflection of heat, 
 D,i, 197,200; E, 635; 
 J, 333. 
 
 foci, 1,277; J, 434. 
 convex, B, 268; E, 744; F, 285 { G, 
 
 311; J, 435. 
 
 formation of images by, F, 
 285 ; reflection from, F,384. 
 curved, F, 283 ; I, 274. 
 foci of concave, E, 746. 
 
 conjugate, I, 277; J, 434. 
 rules for conjugate foci of con" 
 
 cave mirrors, E, 747- 
 convex, J, 435; N, 231. 
 curved, F, 283. 
 principal, I, 276. 
 spherical, J, 442. 
 
 images from, E, 738; 749; F, 286, 
 419, etseq., 470; G, 303; J, 
 437-439; N, 230. 
 formed by concave, E, 749; 
 by plane, E, 738; mul- 
 tiplied by glass, E, 739, 
 for light, E, 734. 
 parallel. G, 306. 
 
 plane, E, 737; E, 419-421; F, 282; 
 G, 303; I, 270; images formed by, 
 F, 282; reflection from, E, 737; 
 F, 282. 
 
 Mirrors, secondary, axes of, E, 746. 
 spherical, B, 268; E, 744; E, 426; 
 
 J, 432, 439-442. 
 aberration of, E, 753; E, 
 
 437 ; F, 296. 
 silvering of, by mercury, D, n, 931 ; 
 
 by reduced silver, D, II, 1031. 
 telescope, J, 498. 
 Mists, B, 596; E, 1067; G, 273; J, 
 
 837. 
 
 Mixture different from chemical combi- 
 nation, D, i, 8. 
 Mobility, E, 25 ; J, 3, 8. 
 Modern science, alleged materializing 
 
 tendency of, K, XI. 
 Modulus of elasticity, see Elasticity. 
 
 a machine, A, xi, 327. 
 Manser's figures, see Roric figures. 
 Moisture, see Vapor of water. 
 Molecular action in wood, effect of, L, 
 
 241. 
 
 attraction, E, 31 ; J, 60. 
 equilibrium, B, 72. 
 forces, see Forces. 
 
 Tyndall on, A, '68, 102. 
 repulsion, E, 36. 
 state, ,1, 2. 
 
 structure and velocity of sound, M, 40. 
 vibration and heat, E, 763; L, 74; 
 
 see Heat, dynamical theory, etc* 
 Molecules, E, 20; G, 14; K, 39; 
 
 J, 1. 
 
 Moment, definition of, C, 100. 
 Moments, equality of, A, xi, 327. 
 Momentum, A, xi, 325; C, 37; E, 
 125; E, 43; F, 77; G, 64, 65, J, 
 13; N, 27. 
 of air, G, 187. 
 Monochord, B, 241; E, 450; E, 
 
 367; J, 201; M, 86; N, 190. 
 Monsoon, A, xi, 667; B, 582; G, 283. 
 Moonbeams, cause of putrefying power 
 
 of, L, 418. 
 
 Moon blindness, cause of, L, 418. 
 effect of striking the earth, K, 304. 
 heat of, L, 422. 
 
 influence of, on weather, G, 291. 
 Mordants, D, n, 820, HI, 546. 
 Morin's apparatus, E, 72; J, 64. 
 Mortars and cements, D, n, 793. 
 Mortise, G, 118. 
 
77 
 
 Motion, A, xi, 317; B, 148; E, 114; 
 
 F, 71; G, 62; I, 23; J, 8,9; K, 25, 
 
 186; N, 22. 
 absolute, apparent and relative, A, xi, 
 
 319; G, 62. 
 accelerated, due to gravity, A, xi, 
 
 322; B, 150; F, 84; G, 63; 1,23; 
 
 formula for, F, 84. 
 
 as an affection of matter, K, 25, 186. 
 apparent, affected by distance, G, 359. 
 of bodies in curved paths, F, 88; 
 
 down inclined planes, F, 85. 
 of central forces, analysis of, B, 158; 
 
 E, 176. 
 
 centrifugal, F, 72; J, 31; N, 23; see 
 
 Centrifugal motion, 
 circular, G, 78. 
 
 common, not interfering with particu- 
 lar, E, 122. 
 composition of, A, xi, 319; B, 158; E, 
 
 119, 176; E, 44; F, 75; G, 72; 
 
 N, 32 ; examples of the, E, 120. 
 compound, A, xi, 320; G, 27; E, 
 
 122; G, 72. 
 
 conversion of, into heat, A, ix, 21. 
 curvilinear, A, xi, 319, 320; C, 29; E, 
 
 51; F, 87; J, 12,31,32; N, 23. 
 diffusion of, requires time, E, 130. 
 dynamical, of molecules, E, 708. 
 on earth's surface produced by heat of 
 
 the sun, A, xi, 415. 
 effect of on affinity, D, n, 1101. 
 of electricity interfered with by the 
 
 motion of heat, L, 226. 
 an essential property of matter, C, 21. 
 first law of, A, vm, 615, and xi, 321 ; 
 
 F, 72. 
 
 of fluids, gases, etc., see Gases and 
 
 Liquids, 
 gravity a source of. A, xi, 322; E, 
 
 151. 
 heat is an expansive, Bacon, L, 67 ; 
 
 Rumford, L, 70; Locke, L, 39. 
 and heat, their relations, A, rx, 21, 
 
 and xi, 415; E, 708; L, 39, 67, 70, 
 
 226. 
 
 of heat interferes with that of electric- 
 ity, L, 226. 
 , irregular, A, xi, 319. 
 Jaws of, A, vni, 615, and xi, 318-325; 
 
 E, 134; F, 72; N, 22-24. 
 
 Motion may be made to evolve the other 
 forms of force, A, ix, 21. 
 
 is never destroyed, A, xi, 321 ; K, 27. 
 
 not imparted to a body instantaneous- 
 ly, G, 65. 
 
 opposition to, F, 72-85. 
 
 opposed by friction, F, 85 ; by resist- 
 ing media, F, 85. 
 
 origin of the idea, C, 21. 
 
 originated by the other forms of force, 
 A, ix, 21. 
 
 oscillatory, A, xi, 324; N, 108. 
 
 parallelogram of, C, 27. 
 
 perpetual, see Perpetual motion. 
 
 persistence of, A, xi, 321. 
 
 point of maximum in a glacier, L, 
 210. 
 
 is possible in several directions at 
 once, C, 22. 
 
 from power through machines, E, 
 196. 
 
 of projectiles, E, 103 ; F, 85. 
 
 produces heat and other forces, K, 28, 
 37. 
 
 quantity of, B, 168; J, 13. 
 
 rectilinear, A, xi, 319; F, 74; G, 111; 
 J, 12 ; of the atoms of gases, L, 76. 
 
 reflected, A, xi, 320; F, 74; G, 71. 
 
 a relative term, C, 21. 
 
 resolution of, A, xi, 319; E, 119; F, 
 75 ; N, 32 ; examples of the, E, 
 121. 
 
 and rest, I, 22. 
 
 retarded, B, 150; I, 23; N, 87. 
 
 reversion of, by belting, G, 101. 
 
 rotatory, F, 86, 87; G, 111; of bodies 
 on horizontal and vertical axes, F, 
 86, 87, 
 
 a signal of force, D, I, 425. 
 
 second law of, A, vm, 615, and xi, 
 320; F. 73. 
 
 simple, illustrations of, G, 73. 
 
 sources of irregularity of, in machin- 
 ery, N, 66. 
 
 third law of, A, xi, 325 ; F, 74. 
 
 three laws of, A, xi, 318; F, 72, 73, 
 74. 
 
 transference of, from mass to mole- 
 cules, L, 74. 
 
 translation of, A, xi, 319. 
 
 uniform, B, 148; C, 23; E, 30; 1,23. 
 
78 
 
 Motion uniformly retarded or acceler- 
 ated, C, 23,26; E, 118; E, 32; 
 G, 63; J, 28: formula for, C, 24- 
 2T. 
 variable, C, 23; E, 117; E, 31; I, 
 
 23. 
 
 varieties of, E, 115; E, 28. 
 vast effects of, K, 217. 
 vibratory, B, 207; see Vibrations, 
 when imperceptible to the eye, G, 359. 
 Motions, compound, A, xt, 320. 
 
 uniform, formula for, C, 23. 
 Motors, enumeration of, A, xi, 326. 
 Mountains, are good condensers, why, 
 
 L,i482, et seq. 
 
 height of, how determined, see Barom- 
 eter and Boiling point. 
 Mountings for telescopes, E, 505. 
 Mouth pipes, E, 380; J, 204. 
 
 resonance of, M, 197. 
 
 Moving bodies, velocities of, F, 76; N, 24. 
 force, see Momentum, 
 or dynamic energy, defined, L, 161. 
 power, A, xi, 326; of steam, L, 133. 
 Multiple proportions, law of, D, i, 13. 
 Multiplier, J, 697. 
 Music halls, E, 442; E, 362. 
 
 and noise, difference between, M, 48, 
 
 83. 
 
 theory of, E, 363; J, 191. 
 Musical box, M, 132, 166. 
 
 consonance, notions of the Pythago- 
 reans concerning, M, 288. 
 instruments, A, '63, 428; E, 466; E, 
 
 383 ; J, 204. 
 reed, A, '66, 666. 
 stringed, I, 175 ; J, 212. 
 wind, I, 181; J, 204, 213. 
 note?, B, 236; F, 143; G, 196; 1,169; 
 J, 192-194; N, 193; Euler's, 
 F, 145. 
 
 how indicated, G, 196. 
 obtained by burning coal gas, 
 L, 284, et seq., 287; D, II, 469; 
 E, 465. 
 
 pitch of, D, I, 120; I, 169. 
 scale, E, 449; E, 366; I, 170; G, 
 
 196. 
 
 new, E, 373. 
 
 sounds, E, 335; G, 194; N, 187, 189; 
 M, 1, et seq. 
 
 Musical sounds of burning gases, D, n, 
 469; E, 465 ;L, 284, 
 etseq. ; see Flame. 
 
 of heated metals, F, 148. 
 from magnetism, E, 
 916. 
 
 action of, on jets of 
 smoke, M, 244. 
 
 produced by gyroscope, 
 
 M, 52. 
 temperament, J. 194. 
 
 Nascent state, D, n, 1120; J, 62. 
 Natural diapason, E, 395. 
 
 philosophy, A, xu, 119; E, 9; G, 
 
 9; N, 13. 
 Nearsightedness, A, xvi, 129; B, 303; 
 
 E, 794; E, 485; G, 352. 
 Nebula, A, xu, 157. 
 Nebular hypothesis. A, xir, 158; H, 522 ; 
 
 K, 230. 
 Nerve force and electricity, how related, 
 
 A, xix, 21; F, 268. 
 source of, K, 430. 
 Newton's disc, J, 468. 
 
 formulae for the velocity of sound, E, 
 
 653; M, 27. 
 rings, E, 837; E, 530; F, 311; J, 
 
 647; N, 262. 
 NicoPs prism, D,-l, 159, note; E, 859; 
 
 E, 553; F, 319; H, 606; J, 555. 
 Nitric acid, table of specific; gravity of, 
 
 B, 107. 
 
 Nitro- glycerine, A, '66, 546. 
 NobilPs rings, E, 996; E, 894; J, 
 
 725. 
 Nodal figures, E, 397; E, 317. 
 
 linns, E, 393; determination of, E, 
 394; deliueitiou of, E, 39tf;-in 
 sounding bodies, D, i. 121. 
 points, E, 385; F, 81, 147; see 
 
 Nodes. 
 Nodes, D, i, 121.; E, 385, 393; E, 
 
 305,313; F, 81, 147; M, 97, 98. 
 determination of, E, 394. 
 the organs of vibration, M, 209. 
 position of, E, 314. 
 not at rest, M, 100. 
 of a tuning fork, M, 137-139. 
 made visible, E, 396; E, 316; M, 
 139-141. 
 
79 
 
 Noise, E, 355; J, 171. 
 
 ho\v produced by insects, G, 205. 
 
 physical difference between music 
 
 and, M, 48. 
 
 Nomenclature of Faraday, E, 882. 
 Nonconductor, see Heat, Electricity. 
 Nut of a screw, G, 108; J, 26. 
 Nutation, A, xn, 449; H, 539. 
 
 Object glasses, A, xi, 475; E, 816; J, 
 
 485. 
 
 American, A, xv, 355. 
 compound, E, 817. 
 for microscopes, E, 508. 
 Observation and experiment, E, 1; 
 
 E, 2. 
 Occlusion of hydrogen by metals, A, 
 
 '68, 100. 
 
 Ocean, depth and extent of, G, 123. 
 influence of, on climate, G, 268; L, 
 
 160. 
 
 Octave, F, 144; G, 195; M, 71. 
 Odometer, A, xn, 488. 
 CErsted's experiments, B, 115,439; E, 
 
 903; G, 429; N. 326. 
 Ohm's formula, F. 222. 
 
 law of retarding power, B, 447; E, 
 
 983; E, 880. 
 theory of the voltaic circuit, D, I, 349, 
 
 353. 
 
 Oil, IIOVY it lessens friction, G, 112. 
 Ombrometer, B, 600. 
 Opacity, not perfect, D, I, 122. 
 Opaque bodies, E, 719; F, 278; G, 
 
 294; I, 261; J, 415. 
 Opera glass, E, 494; G, 365. 
 Ophthalmoscope, J, 530. 
 Optic angle, E 782; E, 471; J, 516. 
 axis, B, 342; E, 782; E, 471; J, 
 
 516. 
 of crystals, D, r, 148; K, 171. 
 
 relation to their mag- 
 netism, 1), I, 423. 
 Optical centre of lens, E, 765; E, 
 
 452. 
 instruments, E, 493; F, 345; G, 
 
 360; I, 323; J, 481. 
 properties of glass, unannealed, F, 332. 
 Iceland spar, F, 315; mica, F, 327, 
 330; nitre, F, 331, 335. 
 
 Optical properties of quartz, F, 337; 
 selenite, F, 327; topaz, F, 830; 
 zircon, F, 291, 316. 
 toys, E, 797; E, 488. 
 Optics, A, xn, 535; E, 397; G, 292; 
 
 1,259; N, 221. 
 medium in, G, 312. 
 Optometer, B, 303; J, 518. 
 Organ, Poole and Alley's, E, 375. 
 pipes, see Pandean pipes, B, 233 ; J, 
 
 206; M, 178,213. 
 open, M, 182, 214. 
 reeds, M, 192. 
 state of air in sounding, M, 185, 
 
 214. 
 stopped, vibrations of, M, 180, 
 
 213. 
 Organs, reed, A, '68, 664; M, 192. 
 
 of hearing, G, 201. 
 Organic beings, source of their motions, 
 
 K. 237 ; L, 85. 
 coordination, K, 410. 
 correlations, Grove on, K, 172. 
 and inorganic growth, E, 51, 52. 
 kingdoms, their relations, K, 433. 
 motion, Mayer on, L, 85. 
 solutions, osmose in, E, 248. , 
 
 structures, table of conductivity of, L, 
 
 242. 
 Organization, distinction between high 
 
 and low grades of,. K, 408. 
 Oscillation, centre of, E, 165 ; E, 
 
 83; N, 108. 
 
 defined, Oscillations, J, 33. 
 Oscillations of elasticity, E, 46. 
 barometer, B, 579. 
 method of J, 596. 
 Osmometer, D, i, 72; C, 387. 
 Osmose, or osmotic action, C, 387, 389; 
 E, 246-249 ; H, 559 ; see Endos- 
 mose. 
 
 of gases, D, I, 88; E, 306. 
 conditions necessary for, E, 300. 
 how allied to chemical action, C, 391. 
 with inorganic solutions, E, 304. 
 laws of, D, I, 73. 
 materials for septa in, E, 301. 
 with organic solutions, E, 303. 
 positive and negative, D, I, 73. 
 theories of, E, 305. 
 
80 
 
 Outcrop, J, 84. 
 
 Overtones, definition, M, 117. 
 influence of, on harmony, M, 301. 
 relation of the point plucked to the, 
 
 M, 119. 
 
 of a rod fixed at both ends, M, 128. 
 rods vibrating longitudinally, M, 
 
 166. 
 
 the syren, M, 293. 
 tuning forks, M, 137-139. 
 made visible, M, 139-141. 
 Oxyhydrogen blowpipe, see Blowpipe. 
 Ozone, E, 859; J, 671. 
 
 Paddles of steamboat, when most effect- 
 ive, G, 154. 
 Pallet, J, 59. 
 Pandean pipes, M, 182. 
 Papin's digester, B, 528; D, i, 229; E, 
 
 680; H, 181; 1,234; J, 286. 
 Parabolic curves, F, 85; G, 74. 
 Parachute, E, 342 fcE, 273 ;L I, 153; 
 
 J, 145. 
 
 Parallax, A, xn, 750. 
 Parallel forces, resultant of, E, 4$. 
 
 of latitude, J, 60. 
 Parallelogram of forces, B, 44. 
 
 rotations, E, 56. 
 velocities, E, 84. 
 Paramagnetism, see Magnetism. 
 Parathermic rays, F, 894. 
 Paratonnerres, see Lightning rods. 
 Parhelia, B, 612; E, 537. 
 Particles of matter, space between, L, 
 
 110. 
 
 ultimate, im pact 
 of, gives 
 the sen- 
 sation 
 of heat, 
 L, 77. 
 motion of, 
 is heat, 
 L, 39, 
 
 in what sense Grove 
 uses the term, K, 
 39. 
 
 Passive resistance, E, 136. 
 state of iron, D, n, 891. 
 
 Pendulum, A, xi, 324; B, 163; C, 66; 
 E, 161; E, 78; F, 88; G, 35; 
 H, 565; 1,58; J, 33; N, 105. 
 how affected by air, C, 75. 
 amplitude of oscillation, B, 164; C, 
 
 68; H, 566. 
 applications of the, E, 166 ; E, 84, 
 
 87; 1,61; J, 58. 
 Bailey's, N, 109. 
 Balistic, A, n, 539; E, 131; E, 
 
 104. 
 
 Bessel's experiments on, C, 74, 76. 
 Borda and Cassini's experiments on, 
 
 0,74,76; N, 109. 
 
 compensating^ C, 506; E, 534; E, 
 696; F, 91; G, 60; I, 
 213; J, 245 ;N, 111. 
 formula for, C, 506. 
 with strips, J, 246. 
 compound, B, 170; C, 66, 69; E, 83; 
 
 1,59; N, 105. 
 length of, J, 56; N, 108. 
 conical, J, 34. 
 
 cycloidal, E, 85; F, 89; N, 107. 
 definition of, C, 66. 
 demonstrates the earth's rotation, E, 
 
 164; E, 86. 
 determination of gravity by, C, 73; 
 
 E, 87; F, 89. 
 electrical, J, 607. 
 formula for, C, 68, 69, 73, 75, 76 ; E, 
 
 81 ; F, 89. 
 
 gridiron, C, 505; F, 91; J, 245; N, 111. 
 isochronism of, C, 68; E, 80; F, 88. 
 Rater's, N, 109. 
 
 experiments on, C, 12, 71. 
 laws of, verified, J, 57. 
 length of, E, 89; F, 89; G, 59. 
 virtual, C, 70, 
 seconds, D, I, 25, note ; E, 
 
 89; G, 61. 
 
 a measure of time, C, 71. 
 mercurial, J, 246. 
 motion of, J, 33. 
 oscillations of, B, 164; F, 88; G, 58; 
 
 N, 105. 
 
 amplitude of, C, 68. 
 centre of, C, 70; F, 91; 
 G, 59. 
 
81 
 
 Pendulum, oscillations of, cycloidal, F, 
 
 W, 
 isochronous, 
 
 F, 88. 
 
 laws of, C, 
 69; E, 
 162, 163; 
 I, 60; J, 
 37. 
 
 time of, G, 
 58 ; N, 
 106. 
 
 propositions respecting, E, 82. 
 rotation of earth, demonstrated by, E, 
 
 164. 
 simple and compound, C, 66, 69; E, 
 
 79. 
 
 theory of, C, 67. 
 use of the, as a standard of measure, 
 
 G, 61. 
 
 virtual length of, C, 70. 
 Penetrating power of microscopes, E, 
 
 513. 
 telescopes, E, 
 
 507. 
 Penumbra, E, 729; E, 411; J, 416; 
 
 N, 223. 
 
 Perception of distance, see Distance. 
 Percussion, F, 91. 
 
 a source of heat, E, 740. 
 Perfect concord, E, 372. 
 Perfumes, how propagated, L, 76. 
 Periscopic glasses, J, 528. 
 Perkin's apparatus, E, 731. 
 Perpetual motion, A, xi, 315, and xm, 
 151: E, 135; G, 91; K, 191, 192, 
 212, 219,^221, 223, 388. 
 Personal equation, A, xm, 173. 
 Perspective, A, xm, 173 ; G, 356. 
 
 aerial, A, xvi, 133; E, 791. 
 Perspiration, use of in hot climates, 
 
 L, 230. 
 
 Phantascope, E, 797. 
 Phantasmagoria, A, xi, 56; I, 336. 
 Phantasmoscope, A, xvi, 131. 
 Phases of undulations, E, 304. 
 Phenakistoscope, B, 310; E, 797; J, 
 
 525. 
 
 Phenomenon, E, 2 ; J, 2. 
 Philosophy, inductive, E, 81. 
 11 
 
 Philosophical egg, E, 852. 
 Phlogiston, theory of, A, v, 34. 
 Phonautograph, J, 223-225. 
 Phosphorescence, A, x, 514, xm. 281; 
 
 E, 399,534; J, 531-535. 
 developed by electric discharge, F, 
 
 200. 
 
 diamonds have no, A, vi, 442. 
 Phosphorescent bodies, D, i, 117. 
 Phosphori solar, D, i, 140. 
 Phosphorogenic power of the spec- 
 trum, D, i, 140; J, 471. 
 Phosphoroscope, J, 533. 
 Photo-electric lantern, E, 884. 
 Photogenic drawing, D, IT, 1135. 
 Photographic action of red glass, D, 
 
 n, 1148. 
 
 apparatus, A, '62, 426. 
 engraving, D, n, 1141. 
 image, latent, D, n, 1136. 
 impressions, fixing of, D, n, 1138, 
 
 1140. 
 
 printing, D, II, 1135. 
 uses of Judean bitumen, D, n, 1141. 
 silver, iodide of, D, n, 1136, 
 
 1143. 
 
 Photographs, development of collodion, 
 
 D, n, 
 1140. 
 
 talbotype, 
 D, n, 
 1137. 
 
 use of 
 sulphate 
 of iron 
 in the, 
 D, ii, 
 1140. 
 fixing of, use of cyanide of potassium 
 
 in the, D, n, 1140. 
 on glass and albumenized paper, J, 
 
 512. 
 
 paper, J, 511. 
 negative, D, H, 1135. 
 positive, D, n, 1135, 1138. 
 Photography, A, xm, 286; A, '66, 
 617; B, 344; E, 826; E, 519; 
 
 F, 387; I, 350; J, 509-512. 
 chemistry of, K, 111. 
 influence of color on, D, n, 1149. 
 
82 
 
 Photolithography, D, n, 1142. 
 Photometer, A, x, 517, and xm, 290; 
 E, 414; G, 298; H, 579; J, 424- 
 426. 
 
 Astro-photometer, results of, A, '66, 46. 
 Bunsen's, A, x, 517; E, 733; J, 425. 
 Wheatstones, F, 242; J, 425. 
 Photometry, A, x, 517: D, i, 124; F, 
 
 279; 1,265. 
 Photometric consideration of the sun 
 
 and stars, A, '63, 151. 
 Photosphere of sun, action of, on solar 
 
 rays, L, 429. 
 Physical agents, I, 11 ; J, 2. 
 
 changes, how distinguished from 
 
 chemical, C, 4. 
 force, see Forces, 
 geography, A, xm, 29&. 
 optics, E, 527. 
 pores, E, 23. 
 properties, how distinguished from 
 
 chemical, C, 6. 
 science of the present distinguished 
 
 from that of the past, K, 402. 
 states of matter, D, i, 3. 
 tables, E, p. 669. 
 
 Physics, definition of, B, 26; G, 10; 1, 11. 
 how distinguished from chemistry, C, 
 
 5; E,9. 
 objects of, J, 1. 
 subjects of, E, 4. 
 Piano wires, clang of, M, 121. 
 
 curves described by vibra- 
 ting, M, 123. 
 friable, E, 180. 
 Picard's discovery, B, 400. 
 Piezometer, J, 69. 
 
 Pile, B, 407 ; D, I, 321 ; E r 967 ; E r 
 864; F, 219; G, 404; J, 684-696; 
 L, 434; N, 814. 
 Baconia's, F, 273. 
 carbon, I, 437. 
 chemical effects of the, B, 421 ; E, 
 
 990. 
 chemical theory of the, E, 999; I, 
 
 436. 
 
 closed, B, 410. 
 Deluc's, D, 1,375; E, 979. 
 dry, A, vn, 68; B, 410; E, 979; F, 
 
 225. 
 La Grave's, F, 273. 
 
 Pile, magnetic and electrical effects of 
 
 the, E, 998. 
 physiological effects of the, E, 997, 
 
 '998. 
 
 source of electricity in, F, 219. 
 theory of action of, E, 999. 
 thermo-electric, see Electricity, ther- 
 
 mo pile. 
 
 voltaic, see Pile. 
 Wollaston's, E, 973. 
 Zamboni's, B, 404; D, I, 376; E, 
 979; F, 225; J, 695; G, 404. 
 Piles, grouping of, E, 982. 
 Pinions, N, 52. 
 
 Pipes, see Organ pipes, and Liquids, dis- 
 charge of. 
 
 Pisa, tower of, see Leaning towers. 
 Pitch, E, 444; G, 195; M, 57. 
 concert, J, 195. 
 
 depends on rapidity of vibration, L, 271. 
 illustration, 
 
 M, 67. 
 
 influence of, on flames, M, 239. 
 relation oif, to velocity, M, 171. 
 Plane, J, 24. 
 
 the inclined, B, 48. 
 
 Planetary atmospheres, K, 137; see 
 "Roscoe's Spectrum Analysis." 
 motions, K, 267. 
 system, structure of, K, 230. 
 Planets, temperatures of, K, 121. 
 Plants, chemistry of, K, 420. 
 Plastic theory of ice, L, 203. 
 Plaster of Paris, D, i, 800. 
 Plateau's experiment, E, 200. 
 Plates, vibrations of thin, E, 312 ; N, 
 
 194. 
 
 Platform scales, G, 98. 
 Platinode, D, i, 370. 
 Platinum spongy, action of hydrogen 
 
 on, D, i, 80. 
 mode of preparing, 
 
 1), n, 1060. 
 
 Plenum, a universal, K, 134. 
 Pliability, G, 26. 
 Plumb line, I, 42; J, 42; G, 53. 
 
 action of earth on, F, 65. 
 near mountains, E, 141. 
 use of, C, 57. 
 
 Plurality of worlds, K, 122. 
 Pluviometer, J, 840. 
 
83 
 
 Pneumatic dispatch, A, '67, 624; G, 
 
 181. 
 
 experiments, E, 367. 
 ink bottle, E, 359; E, 284; G, 179; 
 
 I, 138. 
 
 paradox, N, 170. 
 syringe, J, 111, 397. 
 trough, C, 311, 680; D, I, 47. 
 Pneumatics, A, xm, 410; E, 252; G, 
 
 163; H, 586; N, 153. 
 Polariscope, see Light polarized. 
 Polarity, A, xi, 61; D, i, 264; E, 871; 
 
 H, 590. 
 
 chemical, A, IX, 637. 
 of the compound circuit, E, 981 ; E, 
 
 878. 
 
 electrical, J, 687, 684; G, 419. 
 Polarization, electric, F, 174, 212 ; of 
 
 electrodes, F, 230 ; see Electric, 
 of light, see Light, 
 magnetic, F, 154; see Magnetic. 
 Poles of earth, F, 156; G, 426; J, 53. 
 magnets, B, 347; F, 154; see Mag- 
 nets. 
 
 Polymerism, A, ix, 635. 
 Polymorphism, C, 184; E, 95. 
 Polyrama, I, 338. 
 Poole's musical scale, E, 373. 
 
 and Alley's organ, E, 375. 
 Pop gun, G, 167. 
 
 Pores, physical, E, 23; G, 14, 15. 
 sensible, E, 24. 
 size of, Herschel's opinion, C, 113. 
 Porosity, A, xm, 493; B, 30; C, 110; 
 E, 24; E, 23; G, 14; I, 15; J, 
 3-6 ; N, 19. 
 application of, J, 7. 
 of bodies, proofs of, D, i, 3. 
 cast iron, A, ix, 590. 
 Florentine experiments on, C, 112. 
 illustrations of, C, 111. 
 implies compressibility, C, 113. 
 relation of, to weight and density, E, 
 
 25. 
 Porous water jars, C, 608; see Alcar- 
 
 azzas. 
 
 Position of a body, how defined, C, 20. 
 origin of the idea of, 
 
 C, 20. 
 Positive on glass, J, 612. 
 
 elements (in Chemistry), A, vn, 65. 
 
 Positive and negative crystals, E, 857 ; 
 
 E, 551. 
 
 electricity, see Electricity. 
 Potential or possible energy defined, H, 
 
 602; L, 151. 
 Pound, J, 94. 
 
 Avoirdupois, J, 11, 14. 
 Troy, C, 90. 
 
 United States' standard, C, 90. 
 Power, E, 191 ; N, 41. 
 
 adaptation 'of, to weight, E, 195; E, 
 
 HO. 
 
 agents of, in nature, G, 87. 
 of a force, C, 37, 52. 
 expended in work, G, 89. 
 gain in, is lost in time or velocity, A, 
 
 xi, 327. 
 mechanical effect, how estimated, G, 
 
 92. 
 
 of a microscope, J, 485. 
 moving, effect of how expressed, G, 
 
 89. 
 necessary waste of, in machines, A, 
 
 xi, 327. 
 
 origin of terrestrial, K, pp. 236, 340. 
 ratio of, to resistance, F, 94. 
 relation of, to weight, E, 194; E, 
 
 106-109; G, 92. 
 and resistance, G, 63. 
 solar, maintenance of, L, 435. 
 space and time, how exchanged for, 
 
 G, 92. 
 
 unit of, A, xi, 326. 
 Precession, A, vm, 615. 
 
 of the equinoxes, A, xm, 551; H, 603, 
 Presbyopia, B, 303. 
 Presbytism, J, 518, 527. 
 Preservation of food in a vacuum, I, 
 
 133. 
 wood, Boucherie's 
 
 process, D, in, 95. 
 
 Press, Bramah's hydraulic, A, in, 634, 
 and ix, 412, C, 220; E, 254; E, 
 190; F, 137; G, 127; I, 79. 
 screw, A, xiv, 452; E, 216. 
 Pressure apparatus, Haldat's, E, 240. 
 of the atmosphere, see Atmosphere, 
 centre of, E, 247; E, 197; J, 75, 
 centre of fluid, F, 110. 
 effect of, on point of fusion, A, ix, 21 ^ 
 L, 119, 148. 
 
84 
 
 Pressure, effect of, on crust of earth, L, 
 
 119. 
 equality of liquid, A, ix, 412; B, 76; 
 
 E, 238; J, 71. 
 of fluids, see Fluids, 
 gauge for air pumps, D. I, 43. 
 
 condensed gases, D, I, 255. 
 and the heating of gases thereby, L, 
 
 80, 84. 
 
 hydrostatic, F, 107. 
 of impact, E, 112. 
 independent of form of vessel, J, 73; 
 
 N,24. 
 lateral of liquids, F, 110. 
 
 increases with depth, E, 243. 
 liquefaction of ice by, L, 121. 
 of liquids, N, 122. 
 
 on immersed bodies, J, 84. 
 
 in motion, B, 185; E, 266. 
 
 upward and downward, E f 
 
 239, et seq. ; E, 191 ; 
 
 F, 108; J, 73. 
 
 on wall of containing ves- 
 sels, E, 271; E, 193, 
 214; J, 75; X, 123. 
 lowers freezing and melting point, A, 
 
 ix, 21; L, 119, 148. 
 resistance to, E, 101 ; F, 54. 
 standard for comparison of gases, B, 
 
 1113; D, 1,49. 
 total on walls and bottom of vessels, 
 
 E, 244, 245. 
 transmitted by gases, E, 255. 
 
 liquids, E, 189, 
 
 upward of liquids, E, 241; F, 108, 
 varies with specific gravity, E, 198. 
 of water, see Water. 
 Prime mover (in machines), A, xi, 326. 
 
 seventh, E, 373. 
 Prince Rupert's drops, C, 212, 202, 201 ; 
 
 D, H, 769; E, 178; L, 99; N, 21. 
 Prism, A, xm, 695; B, 292; E, 754; 
 
 E, 438; G, 318; H, 606; 1,292; 
 J, 448-451; N, 234. 
 
 course of luminous rays in, I, 293. 
 experiment with obtuse, N, 259. 
 Nicol's, D, I, 159, note; E, 859; E, 
 
 553; F, 319; H, 606; J, 555. 
 Problems on acoustics, E, p. 289. 
 
 on the elasticity and tenacity of solids, 
 E, p, 146. 
 
 Problems on electricity, E, p. 667. 
 gravity, E, p. 73. 
 heat, E, p. 506. 
 hydrodynamics, E, p. 199. 
 machinery, E, p. 107. 
 optics, E, p. 392. 
 pneumatics, E, p. 234. 
 vibrations, E,*p- 251. 
 on weights and measures, E, p. 37. 
 Projectile force, formula for, E, 129. 
 Projectiles, A, xi, 322; B, 158; E, 168- 
 173; E, 103; F, 84; G, 74, 76; 
 H, 617; N, 90, 91. 
 motion of, F, 84; H, 617. 
 theory of, A, xi, 322 ; H, 617. 
 time of flight of, E, 173. 
 Projection and gravitation, E, 167- 
 
 171; F, 84. 
 
 of a body in a direction other than 
 vertical, E, 171 ; vertically down- 
 wards, E, 169 ; upwards, E, 170. 
 Proof plane, see Electricity. 
 Propellers, why better than paddle 
 
 wheels, G, 155. 
 Psychrometer, A, ix, 421; B, 693; C, 
 
 644; .1,314. 
 Pseudomorphism, A, xm, 642 ; E, 96 ; 
 
 causes of, E, 97. 
 Ptolemaic system, K, 11. 
 Pulleys, A, xi, pp. 327, 328; B, 60; F, 
 
 97; G, 102-104; J, 24; N, 54-57. 
 angular divergence of cords of, F, 99. 
 in the animal economy, F, 103. 
 compound, E, 120; E, 207; F, 99. 
 fixed and movable, E, 206; E, 118; 
 
 F, 97; G, 102, 103; N, 54. 
 formulae for, F, 97, 99, 
 systems of, F, 98. 
 Smeaton's, N, 56. 
 White's, J, 24; N, 57. 
 Pulse glass, X, 209; sonorous, how pro- 
 duced, L, 271. 
 
 Pumps, A, xin, 658-660, XV, 268; B, 
 126-125; D, I, 41; E, 370-374; E, 
 289-293; F, 135; G, 160, 183; H, 
 707; I, 139-142; J, 154-160; N, 171. 
 air, see Air pump, 
 boxes of, G, 181. 
 
 chain, A, xm, 660; E, 370; G,160. 
 forcing, A, xm, 659; B, 126; E, 
 374; G, 183; I, 142. 
 
85 
 
 Pumps, lifting, A, xm, 658, 660; E, 
 
 373; G, 181, 160; 1,139. 
 rotary, A, xm, 659; E, 375. 
 stomach, A, xvi, 268 ; F, 135. 
 suction, A, xm, 659; B, 125: E, 
 372; G, 181; I, 146; when in- 
 vented, G, 160. 
 Vera's, G, 145. 
 Pupil, B, 2S9. 
 
 Pyroheliometer, J, 398; L, 431. 
 Pyrometers, A, xm, 682; D, i, 176; E, 
 518-520; E, 582-585; F, 365; G, 
 233; J, 238 and 816; I, 195; L, 97. 
 Pyrometer, air, C, 539. 
 
 Darnell's, A, xm, 682; D, I, 176; E, 
 
 518; F, 365. 
 
 different forms of the, D, 1, 176. 
 Draper's, E, 519. 
 Saxton's, E, 520. 
 Wedge wood's, A, xm, 682; E, 617; 
 
 F, 365. 
 
 Quadrant, A, xm, 690. 
 
 Qualities of matter, transference of, 
 
 K, 15. 
 Quality of sound, B, 223; E, 363; M, 
 
 117, 127. 
 
 Radiant heat, see Heat. 
 Radiation, see Heat. 
 Railways, atmospheric, A, n, 311. 
 
 illumination of, E, 520. 
 Rain, A, xm, 740; B, 600; E, 1070; 
 E, 980; G, 273, 277; H, 632; I, 
 250; J, 840. 
 annual depth of, E, 1074; E, 983; 
 
 G, 279; H, 633. 
 
 cause of the torrents of, in tropics, B, 
 
 602; L, 188, 401. 
 days of, E, 982. 
 distribution of, E, 1072; E, 981; 
 
 G, 278; L, 190, etseq. 
 fall, J, 841; greater on west than on 
 
 east coast of Ireland, L, 190. 
 gauge, A, xm, 743; B, 600; E, 
 
 1071; G, 277; J, 840. 
 is most abundant where, L, 190, et seq. 
 regions destitute of, E, 1072; G, 279. 
 upon what dependent, L, 190. 
 Rainbow, B, 608; E, 536; G, 333, 
 
 335; J, 859; N, 243-245; A, xm, 
 
 744; E, 840; F, 313; H, 636. 
 
 Range, in gunnery, G, 75. 
 Rarefaction, chilling effect of, L, 44 
 will not by itself lower mean tempera- 
 ture, L, 88. 
 in air pump, J, 149; of Sprengel, J, 
 
 149. 
 
 Reaction, see Action. 
 Receiver, with two barometers, N, 162. 
 
 in machines, A, xi, 326. 
 Reed instruments and Reeds, A, '66, 666; 
 
 J, 205, 206 ; M, 195. 
 pipes, B, 242: E, 381; M, 192. 
 Reflection of heat, etc., see Heat, etc. 
 
 angle of, G, 71. 
 Reflectors, compare Mirrors, A, x, 521 ; 
 
 B, 260; E, 582; E, 748. 
 Refraction of light, sound, etc., see 
 
 Light, Sound, etc. 
 
 Refractometer (Arago's), A, v, 579. 
 Refractory bodies, E, 660. 
 Refrigeration, compare Cold, Heat. 
 
 by expansion of a gas, L, 85. 
 Refrigerators, C, 543; E, 697; E, 
 
 724; G, 221. 
 
 Regelation of ice, compare Ice, L, 199. 
 Faraday's discovery, 
 
 L, 199. 
 
 Thomson's explana- 
 tion, L, 146. 
 
 of snow granules, L, 216. 
 Regulators of machinery, G, 256; N, 66. 
 Relation of atomic weight and specific 
 
 heat, E, 654. 
 
 Repulsion, compare Heat, Electricity, 
 Magnetism, E, 146; E, 36-39; 
 F, 51, 61 ; G, 22. 
 and attraction of floating bodies, F, 
 
 62 ; E, 39. 
 capillary, F, 61. 
 electric, F, 169, 188. 
 molecular, E, 36 ; relation between 
 
 attraction and, E, 39; F, 62. 
 Reservoir, J, 110; of Furens, A, '67, 
 
 675. 
 
 Residual charge, see Leyden jar. 
 Resistance, A, xi, 319,326; E, 219; 
 
 H, 650. 
 
 coils, D, i, 356. 
 of columns, E, 171. 
 fluid, see Fluids, 
 frictional, see Friction. 
 
86 
 
 Resistance of liquids to moving solids, 
 
 A, IX, 416. 
 media, F, 66, 85. 
 to pressure, E, 101 ; F, 54. 
 ratio of power to, F, 94. 
 
 velocity to, F, 95. 
 
 of the voltameter to the voltaic cur- 
 rent, D, I, 354 
 Resistances, mechanical how overcome, 
 
 A, XT, 326. 
 
 Resonance, I, 162; M, 172. 
 of air, M, 172, 213. 
 coal gas, M, 175. 
 mouth, M, 199. . 
 Respiration in cold blooded animals, 
 
 K, 429. 
 
 products of, E, 691 ; E, 718. 
 why it makes air impure, G, 260. 
 Rest, absolute, apparent and relative, 
 
 A, xi, 318; E, 25; N, 22. 
 and motion, I, 22. 
 a relative term only, C, 21. 
 Resultant, E, 46, 47 ; N, 28-31 ; see 
 
 Forces. 
 
 tones, M, 276, 27.8, 281-283. 
 Retina, B, 298; G, 348; N, 246. 
 
 duration of impressions on, E, 796 ; 
 
 E, 487; F, 366. 
 Retinal points, A, xvi, 132. 
 Retorts, E, 643. 
 Return stroke or shock, see Lightning, 
 
 return stroke of. 
 Revolving balls, Gore's experiment, L, 
 
 117. 
 
 lights, E, 523. 
 magnet, E, 914. 
 
 Revolution around axes, E, 178. 
 Rheostat, D, I, 355; E, 1013; E, 
 
 907; ,T, 817. 
 
 Rhigolene, A, '66, 669. 
 Richochet firing, G, 77. 
 Rifle, Minie, G, 77. 
 Rigidity of ropes, E, 142. 
 Ripples, Faraday's & Melde's experi- 
 ments, M, 144, 155, 158. 
 sonorous, in liquids, M, 153, 154, 158. 
 Ritteric rays, ,T, 347. 
 River, Mississippi, does it flow up hill, 
 G, 152 ; quantity of water in, G, 
 152. 
 Rivers, I, 88. 
 
 Rivers, point of swiftest motion in, L, 
 
 209. 
 
 velocity of, G, 152. 
 water discharge of, G, 152. 
 why rarely straight, G, 86. 
 Roads, inclination of how estimated, 
 
 G, 106. 
 
 how they should be made, G, 106. 
 Rockers of Trevelyan's experiments, 
 
 L, 113. 
 Rocksalt and heat, L, 310. 
 
 deposition of moisture on avoided, 
 
 L, 394. 
 
 Herschel's note on, L, 340. 
 hygroscopic nature of, L, 393, 394, 
 
 410. 
 
 transparency of to heat, L, 310. 
 Rods, vibrations of, J, 214. 
 
 fixed at both ends, M, 
 
 128, 157. 
 one end, M, 
 163, 129, 157. 
 free, M, 164. 135, 157. 
 Roget's vibrating spiral, E, 1015. 
 Rooms for speaking, how constructed, 
 
 G, 201. 
 
 Rope dancing, art of, G, 52. 
 Ropes, rigidity of, K, 219. 
 Roric figures, A, xiv, 172; F, 379. 
 Rotascope, E, 181 ; E, 57. 
 Rotation, A, vm, 615, xi, 319, 320; E, 
 
 56; H,654. 
 of eurth, diminution of the, K, 299. 
 
 effect of, on English climate, 
 L, 189; on trade winds, 
 L, 183. 
 
 pendulums show the, E, 86. 
 of electric currents and magnets, E, 
 936; F, 244-250; of electric cur- 
 rents around each other, F, 250 ; 
 of electro-magnets, F, 246 ; of 
 coils of wire between poles of a 
 magnet, F, 248; of magnets 
 around wires conducting electric- 
 ity, F, 244. 
 of moving bodies, F, 86. 
 
 silver medal stopped by magnet, 
 
 L, 60. 
 
 Rotations, parallelogram of, E, 56. 
 Rotating bodies on horizontal axes, F, 
 86 ; on vertical axes, F, 87. 
 
87 
 
 Rotating disks between poles of a mag- 
 net, F, 246. 
 electro-magnets, F, 250. 
 
 Rotary polarization, see Light, polariza- 
 tion of. 
 
 Ruhmkorft's coil, see Coil. 
 
 Rules for philosophising, Newton's, F, 39. 
 
 Rupert's drops, see 'Prince Rupert's 
 drops. 
 
 Rupture* resistance to, C, 201 ; law of, 
 C, 202. 
 
 Safes, fire proof, A, xiv, 255 ; G, 221. 
 Safety tubes, B, 143 ; C, 315-317 ; E, 
 
 379; J, 295. 
 
 formulae for, C, 316, 317. 
 theory of, C, 315. 
 Welter's, C, 317. 
 
 valve, C, 619, 620 ; formula for di- 
 mensions of, C, 620. 
 Salt lakes, origin of, G, 124. 
 Sandstone, a poor building material, G, 
 
 123. 
 Saturated space, see Tension of vapors, 
 
 maximum. 
 Saturation, E, 614, 661, 669; see 
 
 Solution. 
 
 Savart's toothed wheel, E, 441. 
 Scale, chromatic, etc., E, 458; F, 312, 
 
 N, 191. 
 see Balances. 
 
 Science, discovery of its fundamental 
 principle, K, 316; tendency of, 
 towards materialism, K, XII; 
 true scope of, K, XXXI; the great 
 event in the general progress of, K, 
 XVI. 
 
 Scintillating tube, E, 954. 
 Scissors, a variety of lever, G, 94. 
 Sclerometer, C, 209. 
 Screw, A, xiv, 449; B, 50; E, 216, 
 101, 217, 218; E, 127; F, 100; 
 H, 664; N, 60; G, 109. 
 application of the, E, 218. 
 Archimedean, A, n, 32; E, 369; G, 
 
 159; H, 37; N, 149. 
 clock, A, xiv, 451. 
 efficiency of, E, 128. 
 endless, E, 129; G, 110; N, 61. 
 formula for the, F, 101. 
 Hunter's, A, xiv, 449; G, 110; N, 61. 
 
 Screw, mechanical efficiency of, E, 
 
 217. 
 
 propelling, A, xv, 67 ; G, 155. 
 thread, G, 109; J, 25. 
 Sea breeze, how produced, L, 187$ is 
 
 warmer after a storm, L, 20. 
 lights, E, 522. 
 shells, cause of the sound heard in, G, 
 
 199. 
 Seasons, cause of the, A, xi, 415; E, 
 
 947. 
 
 Seventh, harmony of the, E, 373. 
 Sextant, E, 425. 
 Shadow, A, x, 516; B, 253; G, 296; N, 
 
 222. 
 
 colored, B, 314. 
 inflection of light into, F, 308. 
 Shadows, how increase and diminish, 
 
 G, 297, 
 
 Sheathing of vessels, D, i, 331 ; G, 416. 
 Shooting stars, see Meteors. 
 Short-sightedness, B, 303; J, 518, 527; 
 
 G, 352. 
 
 Shot, how made, G, 30. 
 Silver, adulteration of how detected, 
 
 G,43. 
 
 Simoon, A, xiv, 669 ; I, 254. 
 Simmering, G, 241. 
 Simultaneous discovery, examples of, 
 
 K, XV. 
 
 Sine compass, see Electrometer. 
 Sines, law of, see under Light. 
 Singing flames, see Flames and Musical 
 
 sounds. 
 Siphon, A, xiv, 676; B, 121; C, 320; E, 
 
 360; E, 285; F, 136; G, 184 y 
 
 H, 666; 1,147; J, 158; N, 173. 
 intermittent, E, 361 ; J, 158. 
 at Paris, A, '8, 691. 
 Siren, see Syren. 
 
 Sirocco, A, xiv, 678; I, 254; J, 836. 
 Skull, human, combines the principle of 
 
 the arch, G, 120. 
 
 Sky, color of, B, 606; J, 846; L, 408. 
 Smoke, why rises in air and ascends in 
 
 chimney, G, 43, 261. 
 rings, G, 187. 
 
 Sneezing, theory of the act, G, 205. 
 Snow, A, xiv, 750; B, 603; E, 1080 ? 
 
 E, 984; G, 273, 280; I, 251; J, 
 
 847; L, 46,170, 194-213. 
 
88 
 
 Snow-ball, cause of adherence of its 
 
 particles, L, 200. 
 beauty of, L, 194. 
 bridges, how crossed, L, 201. 
 collection of upon mountains, L, 195. 
 colored, E, 1081. 
 crystals, L, 195. 
 formation of, L, 194. 
 
 of glaciers from, L, 197. 
 granules, regelation of, L, 213. 
 limit of perpetual, E, 1053. 
 line the, upon mountains, E, 1053; 
 
 E, 955; G, 248; L, 195. 
 protects against cold, G, 220. 
 regelation of, L, 197, 200, 201, 213. 
 a shower of, produced by the issuing 
 of compressed air, L, 46 ; of car- 
 bonic acid, L, 170. 
 squeezing of into ice, L, 197, 201. 
 Soap bubble, F, 51, 310; G, 43; J, 547; 
 
 see also Bubble. 
 Soda water apparatus, E, 648. 
 Softness, E, 61 ; G, 26. 
 Solar atmosphere, K, 288 ; L, 439; see 
 
 Sun. 
 
 chemistry, L, 429. 
 microscope, G, 368 ; B, 819 ; J, 504. 
 origin of organic life, K, 240; L, 445, 
 
 et seq. 
 
 radiation, measurements of, L, 431. 
 rays, force of those which fall annually 
 upon a square foot of land, A, ix, 
 23. 
 
 physics, A, '67, 69. 
 spectrum, see Spectrum. 
 Soldering? compare Brazing. 
 Solenoid, E, 1017; E, 910. 
 Solid condition of matter, C, 117; E, 
 
 49; F, 42, 51. 
 
 Solid of least resistance, N, 147. 
 Solidification, B, 497; I, 221; J, 65, 
 
 266. 
 
 change of volume",by, E, 617 ; E, 
 664; J, 267; L, 73 ; contraction at 
 moment of, L, 118. 
 elevation of temperature by, E, 616 ; 
 
 E, 663. 
 f expansion at moment of, E, f 87 ; L, 
 
 73. 
 of gases, theory of, E, J688. 
 
 Solidification, laws of, E, ft 615; see 
 
 Gases. 
 Solids, C, 110, 117; E, 49; E, 149; 
 
 F, 42, 51; G, 23. 
 absorption of gases by, C, 379; of 
 
 liquids by porous, C, 363. 
 adhesion between, C, 342; to liquids, 
 
 C, 345. 
 
 calorific transmission by, Melloni's ta- 
 ble, L, 311. 
 
 characteristic properties of, C, 110. 
 compressibility of, C, 113. 
 conduction of heat in, C, 656. 
 elasticity of, is imperfect and limited, 
 
 C, 116. 
 
 expansion of, by heat (table), D, I, 
 175, 166, and in, 767; E, f 528; L, 
 97. 
 
 porosity of, C, 110. 
 specific gravity of, C, 91, 247, 662. 
 structure of, E, 150. 
 symmetry of, E, 50. 
 why easily lifted in water, G, 139. 
 Solubility anomalous of sulphate of 
 soda, etc., C. 372-377; D, I, 66, and 
 ii, 747. 
 
 of gases, causes of variation, C, 398 ; 
 coefficient of absorption 
 of, C, 392; determination 
 of the, C, 398 ; expressed 
 by empirical formulae, C, 
 393. 
 
 when mixed, C, 406. 
 Tariation with the pressure f 
 C, 394 ; the temperature, 
 C, 393. 
 of salts, C. 367. 
 
 solids, curves of, C, 367 ; determi- 
 nation of, C, 369 ; empirical form- 
 ula? of, C, 366; uninfluenced by 
 fusion, C, 369; variation with 
 temperature, C, 365. 
 Solution, E, 614; E, 661; G, 237; J, 
 
 265. 
 
 difference between, and chemical affin- 
 ity, C, 371; D, I, 13, 65; G.237. 
 of gases in liquids, C, 392, 393. 
 Solutions, maximum density of, E, $ 
 
 604. 
 saturated, E, 614; G, 237. 
 
89 
 
 Solutions, supersaturation of, A, ix, 
 
 433; C, 376. 
 
 Sonometer, E, 450; E, 367; M, 86. 
 Sonorous waves, etc., see Sound. 
 Sounding bodies are in vibration, E, 
 
 418. 
 
 Sound, compare Acoustics, E, 417; E, 
 335; F, 138; I, 156; G, 188; J, 
 171, 184; N, 176, 181. 
 analogy of, and light and heat, D, I, 
 
 118; K, 259; L, 300; M, 13. 
 boards, M, 89. . 
 
 calculation of distance by, E, 426 ; 
 
 E, 346; F, 140. 
 
 communication of, see below, propa- 
 gation of. 
 conducting power of bodies for, A, 
 
 v, 579; F, 140-142; G, 191. 
 currents of electricity, cause, J, 749. 
 distance to which propagated, E, 
 423, 425, 432 ; in air, E, 423 ; 
 in gases, E, 425. 
 Duhamel's graphic method, J, 189. 
 figures, M, 202-207. 
 formula for, J, 179. 
 inflection of, M, 22. 
 intensity of, E, 445; E, 363; F, 
 139; G, 194; I, 164; J, 
 174, 192; M, 57, 83. 
 circumstances modi f ying 
 the, F, 139; I, 164; laws 
 of the, F, 139 ; in tubes, 
 I, 165. 
 
 interference, E, 349; E, 429; F, 
 141; G, 194; M, 259, 261-263, 272, 
 284. 
 
 law of decrease of its intensity, G, 192. 
 and light, K, 259. 
 limits of perceptible, G, 190; I, 169; 
 
 J, 188. 
 
 by magnetization, A, vn, 72, n, 62. 
 mode of its transmission, see below 
 
 propagation, 
 musical differs from noise in what, B, 
 
 222; F, 138; I, 168. 
 non-propagation of, in a vacuum, B, 
 224; E. 433; E, 339; F, 138, 
 142; I, 159-162; L, 259; M, 6, 44. 
 passage of through mixed media, F, 
 141. 
 
 12 
 
 Sound pitch, I, 169; M, 57, 83. 
 planes of vibration of, F, 143. 
 polarization of, A, i, 76. 
 
 produces heat, M, 177. 
 produced by combustion of gases in 
 tubes, L, 284; by contact of 
 bodies of different temperatures, 
 L, 112, 142; by flame, L, 261; 
 by cooling silver, L, 112 ; during 
 the magnetization of a bar of iron, 
 A, vn, 72, and xi, 62 ; by Treyel- 
 yan's instrument, L, 113. 
 production of, L, 271; M, 55-57; N, 
 
 194. 
 
 propagation of, A, i, 76; D, I, 119; E, 
 419; E, 337; F, 
 139; G, 190; I, 157- 
 159; J, 176; L, 260; 
 M, 2, 3, 9, 19, 78, 80; 
 N, 181-183. 
 
 in air, I, 157; L, 260; 
 in liquids and solids, I, 159. 
 properties of musical, J, 191. 
 quality, E, 443, 446; E, 363; J, 
 
 191; M, 117, 127. 
 
 reflection of, A, I, 76; B, 224; E, 
 
 433; E, 352; F, 142; G, 197; I, 
 
 162; J, 181; M, 13; N, 185; see 
 
 Echo. 
 
 refraction of, E, 431; E, 357; F, 
 
 141; J, 184; M, 20. 
 of rotating magnets, F, 250. 
 of steam jets, M, 211. 
 time requisite to transmit, A, I, 75. 
 transverse vibrations of, F, 143. 
 the undulations of its waves are longi- 
 tudinal, L, 300. 
 
 velocity of, A, i, 75 ; B, 223 ; F, 140 ; 
 G, 193; J, 178; N, 182. 
 in air, E, 423; E, 344; 
 I, 160; M, 37; dens- 
 ity and elasticity in- 
 fluence, M, 25 ; de- 
 termination of, M, 26, 
 170. 
 
 gases, E, 425; E, 
 
 345; J, 178; M, 25, 37. 
 
 liquids, E, 427; E, 
 
 347; I, 162; M, 37, 
 
90 
 
 Soand 9 velocity of, in metals, M, 39, 40, 
 
 162, 170. 
 
 Newton's formula, C, 
 482; E, 424; M, 
 27. 
 from pitch, M, 191, 
 
 190. 
 
 in solids, E,428;E, 
 
 348; 1,162; M, 
 
 solutions, M, 38, 37, 
 
 39. 
 effect of temperature 
 
 on, M, 24. 
 in water, fresh and 
 
 sea, M, 37, 38. 
 woods, M, 41. 
 
 waves, A, I, 76; F, 145; G, 188, 190; 
 1,167; J r 178, 196; L, 271, 
 300 ;N, 193. 
 are capable of passing each 
 
 other, F, 139; 1,158. 
 how different from waves of 
 
 light, L, 300. 
 Sounds of animals, E, 475-477; E, 
 
 392 ; J, 188. 
 
 compared with colors, F, 279. 
 inaudible, G, 190; L, 273. 
 interference of, E, 429. 
 loud travel faster than faint, A, i, 76. 
 seem louder by night than by day, G, 
 
 191. 
 
 musical qualities of, E, 443. 
 not propagated in a vacuum, see 
 
 Sound, nonpropagation of. 
 not heard alike by all, G, 208. 
 pitch of, I, 169. 
 propagated in elastic bodies, E, 
 
 420. 
 vary in intensity with density of the 
 
 air, F, 139. 
 
 Speaking, rooms suitable for, G, 201. 
 trumpet, A, xiv, 829; E, 438; E, 
 
 358; G, 199; I, 166; N, 186. 
 tubes, E, 437; J, 177; N, 185. 
 Specific gravity, A, vm, 429; B, 39, 97; 
 0,91,247; D, I, 27; 
 F, 52, 113; G,37,38; 
 I, 96 ; J, 11, 89. 
 of alcohol and spirit 
 tables, D, HI, 
 814, 815. 
 
 Specific gravity of bodies lighter than 
 water, how de- 
 termined, G, 39. 
 bottles, C, 247; E, 
 265 ;E, 211; J, 91. 
 discovery of, G, 44. 
 cylinder and bucket, 
 experiment to illus- 
 trate, I, 91. 
 definition of, I, 96. 
 of different substances, 
 table, A, vm, 430 ; 
 F, 117. 
 formulae for, C, 247- 
 
 249, 257. 
 
 of gases, C, 93, 273; 
 D, I, 29, 181; F, 
 116; G, 41; form- 
 ula for, C, 673; 
 table of, D, I, 183; 
 table of (com- 
 pound gases and 
 vapors), D, HI, 760; 
 table of (elemen- 
 tary gases and va- 
 pors), D, in, 769; 
 determined by effu- 
 sion, C, 414, 
 of liquids, B, 97; C, 
 92, 247, et seq., 
 665; E, 268, 
 269; D, 1,28, 61; 
 F, 114; G, 39; I, 
 99; J,79, 93; N, 
 134. 
 
 correction of, for 
 temperature, 
 formula, C, 665. 
 dete r m i n e d by 
 flasks, E, 269; 
 by hydrome- 
 ters, E, 268. 
 and mass, formula for, 
 
 C, 92. 
 of metals, D, n, 671, 
 
 table. 
 
 methods of determin- 
 ing, C, 247, 257. 
 referred to air and wa- 
 ter, formulae for, C, 
 
91 
 
 Specific gravity of solids, C, 87, 91, 
 100, 247, 
 661-664; 
 
 D, I, 29; 
 E, 257- 
 264; F, 
 113; G, 
 39; 1, 97; 
 J,90; N, 
 113, or 
 133. 
 
 corre c t e d 
 for tem- 
 perature 
 formula, 
 C, 663. 
 
 determina- 
 tion of, 
 E,257, 
 264, 266. 
 
 h e avi er 
 than wa- 
 ter, E, 
 
 261 ; 
 1 i g h ter 
 than wa- 
 ter, E, 
 
 262 ; 
 sol u b 1 e 
 in water, 
 
 E, 263. 
 and specific weight, 
 
 formula for, C, 92. 
 etandard for estimat- 
 ing, G, 38. 
 
 of vapors, C, 675 ; D, 
 I, 184, 
 and, in, 
 760; E, 
 657. 
 
 process for 
 determ- 
 ining, D, 
 i,184;E, 
 657, 
 658. 
 and weight, formula 
 
 for, C, 91. 
 weight and volume, 
 
 C, 92. 
 heat, see Heat. 
 
 */, V t 
 
 Specific weight, fdraiula for, C,>Q. 
 
 gravities, various, A f ,ytu, 430; I/, 117. 
 
 heat, see under Heat, i I 
 
 weight, C, 90-92 ; E, 99. ' / 
 Spectacles, A, xiv, 831; G, 360; J, 528. 
 Spectra, ocular, A, xvi, 133. 
 Spectral colors, F, 357. 
 
 illusions, A, xvi, 133. 
 Spectroscope, J, 472, 475. 
 Spectrum, solar, A, xn, 539; B, 285; 
 
 D, i, 134; E, 769; E, 456; G, 
 326; H, 669; I, 311; J, 343, 464; 
 N, 240. 
 
 analysis, J, 472-477. 
 
 of the, K, 62. 
 
 by the electric light, L, 423. 
 bands, E, 298; J, 476; L, 424, 426. 
 calorific properties of, A, xm, 287 ; F, 
 
 304; H, 674. 
 of carbon, L, 428. 
 chemical actions of, D, n, 1147; F, 
 
 304. 
 colors of the, A, v, 494; F, 300; I, 
 
 313. 
 curves expressing properties of the, 
 
 E, 301-305. 
 
 dark lines in, D, I, 136, and n, 1146; 
 E, 774; E, 461; F, 302; J, 471, 
 476; L, 429-430; see Frauenho- 
 fer's lines. 
 
 dispersion of solar, E, 776. 
 distribution of heat in the, A, xm, 
 
 287. 
 
 electric, L, 266-269. 
 invisible, proved, L, 268, et seq, 
 is to the eye what the gamut is to the 
 
 ear, L, 272. 
 
 irrationality of thej F, 302. 
 lavender band of, F, 299. 
 light, distribution of, in, F, 303. 
 of a metal, L, 423. 
 photographic powers of, D, n, 1145. 
 simplification of by absorption, F, 
 
 300. 
 
 of sodium, L, 428, 431. 
 of zinc, copper, etc., L, 425, et seq. 
 Specula, see Mirrors. 
 Speculum metal, D, n, 931 ; H, 675. 
 Speech, see Voice. 
 Speed, see Velocity. 
 Spherical aberration, see Light. 
 
92 
 
 Spheroidal state of liquids, A, vii, 346, 
 xv, 60; C, 361, 
 611-614; D, I, 259; 
 E, 659-673; F, 
 372; G,240; J, 61, 
 303 ; L, 172-178. 
 
 applications of the, 
 E, 672. 
 
 bearing of the on 
 boiler explosions, 
 L, 178. 
 
 Boutigny's experi- 
 ments upon the, 
 C, 613; L, 178. 
 
 causes which pro- 
 duce the, E, 667. 
 
 connection of cer- 
 tain phenomena 
 with the, E, 669. 
 
 explosions produced 
 by, E, 671, 
 
 first observed by Lei- 
 denfrost, L, 177. 
 
 floating of the sphe- 
 roid in its own vor 
 por, L, 172. 
 
 illustrations of the, 
 E, 660; C, 614; 
 L, 172, et seq. on 
 liquid surfaces, E, 
 662. 
 
 the liquid is sup- 
 ported on a bed of 
 Its own vapor, H, 
 788: L, 172. 
 
 proof that the liquid 
 is not in contact 
 1 with the hot sur- 
 face of the metal, 
 L, 175. 
 
 rate of evaporation 
 from, E, 663. 
 
 repulsive action be- 
 tween surface and 
 liquid, E, 666. 
 
 temperature of the 
 vapor from the 
 spheroid, E, 664. 
 Spiral, J, 746. 
 Spirit level, E, 203. 
 Spontaneous combustion, A, v, 632. 
 
 Springs, A, xv, 11; G, 136; I, 88. 
 boiling, of Iceland, L, 134. 
 intermittent, E, 362; E, 286; G, 
 
 185; J, 159. 
 
 Spy-glass, see Telescope. 
 Stability, A, xi, 321; E, 207, G, 48; 
 
 1,48; N, 39. 
 Stalactite, A, xv, 26. 
 Stairs are inclined planes, G, 107. 
 Stars, colored stars Doppler's hypothesis, 
 
 M, 78. 
 
 composition of (chemical), J, 477. 
 heat from, A, xi, 415. 
 shooting, theory of, G, 289, 290; L, 23; 
 
 see Meteors. 
 Statics, A, xi, 318; B, 43; C, 34; E, 
 
 39; F, 49; N, 21. 
 Staubbach, the, J, 51. 
 Steam, A, xv, 43; A, '63, 825; C, 572; 
 N, 209; compare Vapor of water, 
 apparatus, De Caus's, A, xv, 47; 
 Branca's, A, xv, 47; E, 676; 
 Guericke's, E, 677. 
 application of latent heat of, C, 611. 
 behavior of in engine, and how known, 
 
 A, xv, 64. 
 
 boat, first, E, 675; E, 706. 
 boilers, A, xv, 59; 0,616; D, j, 227; 
 
 E, 686; E, 713, 733. 
 Cornish, C, 616. 
 explosions of, see Explosions, 
 high pressure, D, i, 227. 
 carriage for rails, A, xv, 61; for 
 
 roads, A, xv, 64. 
 cylinder (Pupin's), A, xv, 48; E, 
 
 * 680, 
 elastic force of, G, 249; is increased 
 
 by heating, L, 132. 
 electrical machine, B, 384. 
 engine, see below, 
 expansion at formation of, C, 603. 
 used expansively, A, xv, 49, 55, 58 { 
 
 G, 255; N, 220. 
 fire engine, G, pp. 261-254. 
 gauge, G, 259. 
 heating by, G, 265; J, 404. 
 high pressure, A, xv, 45; E, 635; Q> 
 
 250, 
 
 jet, D, j, 234; sound of the, M, 211, 
 is invisible, G, 238. 
 latent heat of, see Heat. 
 
93 
 
 Steam, limit to which expansion can be 
 
 advantageously carried; A, xv, 58. 
 
 mechanical power of, A, xv, 45 ; E, 
 
 686; E, 714. 
 power, E, 189. 
 how produced, L, 128. 
 production of, A xv, 59. 
 pressure of, how indicated, G, 260. 
 saturated, table of properties of, A, 
 
 xv, 47. 
 superheated, A, xv, 45 ; G, 250 ; used 
 
 in engines, A, xv, 58, 57, 55. 
 temperature of, at high pressures, D, 
 
 I, 228, table, 
 whistle, G, 260. 
 
 Steam-engine, A, xv, 47 ; B, 507 ; C, 
 615, et seq.; E, 703; G, 
 251; H, 701; J, 383; K, 220; 
 N, 212. 
 
 action of the, K, 220. 
 atmospheric, A, xv, 48 ; E, 
 
 681; J, 389. 
 
 Branca's, A, xv, 47 ; E, 676. 
 
 condensing, A, xv, 50, 53; C, 
 
 621,625, 633; E, 683; E, 
 
 710; G, 253; J, 394; N, 
 
 216. 
 
 dead points of, A, xv, 52. 
 De Caus's, A, xv, 47. 
 double acting, A, xv, 49; J, 
 
 385-389. 
 essential parts of described, A, 
 
 xv, 50. 
 , Guericke's, E, 677. 
 
 high pressure, A, xv, 50, 55 ; 
 0,628,633; E, 684; E, 
 711; G, 254; N, 214. 
 history of, A, xv, 47; E, 
 
 673. 
 
 Leopold's, A, xv, 48. 
 locomotive, A, xv, 61; B, 520; 
 C, 628; G, 29; J, pp. 390- 
 393. 
 
 locomotive, cars for, A, xv, 61. 
 
 road, A, 
 
 xv, 64. 
 
 low pressure, C, 621, 633 ; E, 
 
 683. 
 
 marine, A, xv, 67. 
 Newcomen's, A, xv, 48; E, 
 6SO; E, 707. 
 
 Steam-engine, noncondensing, A, xv, 
 
 50, 53; C, 628. 
 oscillating, A, xv, 62. 
 parallel motion, C, 624. 
 reaction, J, 393. 
 regulators for, G, 255. 
 Savory's, A, xv, 52,48; E, 
 
 679; N,212. 
 single acting, A, xv, 49. 
 varieties of, A, xv, 53 ; G, 253 ; 
 
 J, 394. 
 
 Watt's improvement of. A, xv, 
 48; E, 682; E, 709; H, 
 701; J, 385. 
 Worcester's, A, xv, 47; E, 
 
 678. 
 
 work of steam in the, A, xv, 
 55, 58; C, 631; G, 251; J, 
 894; N, 219. 
 
 Steel, tempering of, see Tempering. 
 Steel-yards, E, 201; E, 115; G, 97; 
 
 N, 48. 
 
 St Elmo's fire, D, i, 314. 
 Stere, E, 18. 
 
 Stereomonoscope, E, 833 ; E, 526. 
 
 Stereoscope, A, xv, 86 ; E, 832 ; E, 
 
 526; H, 705; I, 354; J, 521-524; 
 
 N, 254. 
 
 Stethoscope, A, n, 367; G, 192; J, 177; 
 
 M, 42. 
 
 Still, D, I, 235; E, 642; G, 243; J, 292. 
 Stomach pump, A, xv, 268; F, 135. 
 Stone for building, see Building stone. 
 Stopcock, doubly exhausting, J, 150. 
 
 Gay Lussac's, J, 300. 
 Storms, law of, A, ix, 385; B, 588; E, 
 
 971; J, 837. 
 
 produced by heated air, L. 182. 
 Stoves, J, 404. 
 
 how different from open fires, G, 263. 
 disadvantages of, G, 264. 
 why placed near the floor, G, 261. 
 why they snap when heated, G, 230. 
 Stratification, D, n, 667. 
 Stratus, J, 838. 
 Straw-fiddle, M, 137, 157. 
 Stream measures, E, 227. 
 Strength, absolute, B, 67 ; E, 100. 
 of animals, E, 185 ; E, 130. 
 of beams and tubes, E, 172. 
 crushing, A, xv, 136. 
 
94 
 
 Strength of cylinders, F, 53. 
 lateral, E, 102. 
 of materials, A, XV, 134 ; E, 99 ; E, 
 
 170; 0,115; N, 72. 
 of men, E 186, 188; E, 181. 
 
 and animals ( tables ), E, 
 
 188. 
 a structure, influence of the parts 
 
 upon, G, 117. 
 
 tensile, A, xv, 134, table, 135. 
 transverse, A, xv, 136; E, 102. 
 Strings, J, 201. 
 
 harmonic tones of, M, 115, 116, 126. 
 laws of vibrating, M, 90; N, ISO. 
 longitudinal and transverse impulses, 
 
 M, 107. 
 
 nodes and ventral segments, M, 97, 96. 
 vibrations of, B, 240; J, 201; M, 86; 
 
 N, 189. 
 
 waves in, direct and reflected, M, 98. 
 stationary and progressive, 
 
 M, 95/ 
 
 Strokknr, imitation of the, L, 139. 
 Structure of bodies as affecting heat- 
 motion, K, 55. 
 metals changed by blows 
 and jarring, A, xv, 138 j 
 D, i, 95. 
 
 Sturm's theory of vision, J, 519. 
 Stuttering, E, 391; E, 474. 
 Sublimation, A, xv, 150; E, 81: G, 
 
 243. 
 Substitution in chemistry, A, v, 42; 
 
 D, in, 44. 
 
 Sucker, the common, G, 175. 
 Suction, a purely mechanical action, A, 
 XHI, 413; B, 126; G, 169; J, 162; 
 see pump. 
 Sugar, how refined, G, 242. 
 
 absorbs water, G, 145. 
 Sulzar's experiment, N, 314. 
 Summation tones, M, 282. 
 Sun, compare Solar, A, xv, 185; E, 
 
 948, 742. 
 
 all energy, whether organic or inor* 
 ganic, derived from the, L, 445, et 
 seq. 
 
 analysis, J, 477 ; L, 430. 
 atmospheric absorption of heat of, L, 
 
 433. 
 beam, composition of, A, vii, 575. 
 
 Sun beam, penetrative power of, L, 320. 
 
 causes of the continuance of the light 
 and heat of, A, xv, 188; L, 58, 436. 
 
 chemical composition of the atmos- 
 phere of, A, xv, 188. 
 
 Constitution of the, L, 422, 429. 
 
 Cooling of, K, 265. 
 
 does not heat dry air to any sensible 
 extent, L, 319. 
 
 does not really rise and set, G, 84. 
 
 flame atmosphere surrounding, L, 439. 
 
 heat of the, see Heat. 
 
 heating power of, A, ix, 23; E, 743; 
 G, 209; L, 431-434; way of meas- 
 uring the, L, 437; why greatest 
 at noon, G, 210. 
 
 illuminating power of, A, x, 517. 
 
 light, analysis of, A, v, 494. 
 
 mechanical value of a cubic 
 mile of, A, ix, 23. 
 
 mass of, constant, K, 282. 
 
 origin of, and planets, L, 430. 
 
 presence of iron and other metals in 
 proved, L, 430. 
 
 production of winds by the heat of 
 the, L, 182. 
 
 radiation of the, mode of determining, 
 L, 432. 
 
 relation of, to animal and vegetable 
 life, L, 445. 
 
 to a small fraction of its heat is due all 
 terrestrial energy, L, 448. 
 
 spots upon the, A, xi, 67, and xv, 186; 
 J,477; K, 286; periodicity of the, 
 A, xv, 186. 
 
 Thomson's theory of, L, 440. 
 
 total amount of heat emitted by, L, 434. 
 
 winds produced by, L, 430. 
 Snpersaturation, A, ix, 433; C, 376. 
 Surface action of charcoal, D, i, 64, and 
 n, 488. 
 
 defined, G, 12. 
 
 a spherical, G, 133, 
 
 unit of, C, 13, 17. 
 Swimming, I, 95; J, 89. 
 
 bladder, see Bladder. 
 Syphon, see Siphon. 
 Syrene, E, 440: E, 360; H, 666; J, 
 186; L, 286; M, 63; N, 188. 
 
 double, M, 76, 289. 
 
 La Tour's, J, 186. 
 
95 
 
 Syrene, rate of vibrations determined 
 
 by, M, 68. 
 singing flame produced by sounding, 
 
 L, 286. 
 
 sounds of, M, 63. 
 Syringe, A, xv, 268; F, 126, 127; G, 176. 
 
 Tackle and fall, G, 105. 
 
 Talbotype process of photography, D, 
 
 11,1136; F, 392. 
 Tangential forces, B, 159. 
 Tangent compass, see electrometer. 
 Tantalus's cup, E, 361 ; F, 136. 
 Telegraph (electric), A, xv, 334; A, 
 
 '63, 427, 828 ; '64, 758 ; '65, 777 ; '66 
 
 719; B, 458; D, I, 390, et seq.; E, 
 
 1026; E, 921-928; H, 713; 1,460; 
 
 J, 750; N, 342; A, '61, 675. 
 Atlantic cable, A, xv, 344, 346, iv, 
 
 183; A, '69,659; E, 1032. 
 Bain's, A, xv, 838; E, 1031: E, 
 
 926 ; G, 436 : J, 761 ; N, 342. 
 chemical, see Bain's, 
 copying, A, XV, 339. 
 dial, J, 754. 
 earth used as part of the circuit, D, I, 
 
 391. 
 
 electro-chemical, A, xv, 338. 
 Gauss & Weber's, A, XV, 336; E, 
 
 1026. 
 
 House's, A, xv, 339 ; E, 1030. 
 Hughes's, A, xv, 340. 
 indicator, A, xv, 338. 
 Morse's, A, xv, 336; E, 1029; I. 462. 
 Phelps's, A, xv, 340. 
 printing, A, xv, 339. 
 registering, A, xv, 338; I, 462. 
 Schilling's, A, xv, 336. 
 Soemmering's, A, xv, 335; E, 1026. 
 Steinheil's, A, xv, 336 ; E, 1026. 
 submarine cables, A, xv, 343; D, I, 
 
 393; I, 467. 
 varieties of, E, 1028. 
 Wheatstone's, A, xv, 337; E, 1028; 
 
 H, 717. 
 wire insulation of, A, xv, 342 ; G, 436 ; 
 
 how charged like the Leyden jar, 
 
 D, I, 393. 
 Telegraphic alphabet, G, 435. 
 
 communication through the earth, G, 
 
 437. 
 
 Telegraphic method, the first proposed, 
 
 G, 436. 
 Telescope, A, xv, 347, et seq.; B, 398; 
 
 E, 806; E, 497; F, 345, et seq. ; 
 
 a, 363; H, 720; I, 323; J, 484. 
 achromatic, A, xv, 552 ; B, 292 ; F, 
 
 S13; E, 504; F, 346; H, 720; J, 
 
 495. 
 astronomical, E, 808; F, 353; I, 325; 
 
 J, 492. 
 
 at Cambridge, E, 815. 
 Cassegranian, A, xv, 851 ; F, 346. 
 catoptric, F, 346. 
 dialytic, A, xv, 354. 
 equatorial mountings for, A, xv, 357 ; 
 
 E,14; E,505; G, 363. 
 eyepieces of, A, xv, 350, 353 ; E, 809. 
 with fluid lens, A, xv, 354, 355. 
 forms of the, A, xv, 347. 
 Frauenhoefer's, A, xv, 353. 
 Galileo's, A, xv, 348; E, 807; E, 
 
 498; F, 353; I, 324; J, 494; N, 257. 
 Gregorian, A, xv, 350; F, 346. 
 Herschel's, A, xv, 352; E, 811; E, 
 
 502; H, 722; I, 330; J, 499; N, 
 
 256. 
 
 history of the, A, xv, 348. 
 methods of mounting, A, xv, 357. 
 Newtonian, A, xv, 351; F, 345; I, 328. 
 object glasses of, A, xv, 353 ; E, 813. 
 reflecting, A, xv, 350, 355, 356; B, 
 
 821; E, 810; E, 501; F, 345; 
 
 G, 365; I, 328; J, 496; N, 255; 
 
 illuminating power of, A, xv, 355. 
 refracting, A, xv, 347, 352; B, 321; 
 
 E, 501; F, 353; G, 363; I, 328; 
 
 N, 256. 
 Rosse's, A, xv, 355; E, 812; E, 
 
 503 ; I, 330. 
 terrestrial, B, 325; 1,327; J, 493; N, 
 
 257. 
 
 Telestereoseope, E,' 831: E, 524. 
 Temper, E, 178; J, 68. 
 Temperament, E, 375. 
 Temperature, B, 575; C, 463; C, 206; 
 
 H, 723; 1,187; J, 228. 
 absolute zero of, A, ix, 18; C, 564; J t 
 
 407; L, 90. 
 
 of air, diminished by elevation, B, 576 ; 
 D, 1,214; E, 602; E, 952, 
 and of swan's-down, L, 421. 
 
96 
 
 Temperature of the animal body, con- 
 stancy of the, L, 229; see Heat, 
 animal. 
 
 artificial, how produced, E, 700. 
 
 average annual how determined, G, 
 267. 
 
 of celestial space, A, xi, 416; C, 564. 
 
 ' correction for in barometer, J, 123. 
 
 definition of, C, 463. 
 
 determined by specific heat of plati- 
 num, C, 473; J, 373. 
 
 difference of between radiating body 
 and air is constant, L, 421. 
 
 difference of between winter and sum- 
 mer, G, 210. 
 
 difficulties in ascertaining the true, L, 
 417. 
 
 distinguished from heat, D, I, 164. 
 
 distribution of, A, xv, 431; B, 606; D, 
 I, 78; J, 866. 
 
 of earth's surface, A, xi, 416; B, 676; 
 G, 267; H, 724; L, 189. 
 
 of England, cause of its equability, L, 
 189. 
 
 high, how endured, L, 229. 
 
 highest natural ever observed, G, 211. 
 
 influence on chemical affinity, D, n, 
 1107. 
 
 of lakes and springs, J, 867. 
 
 of liquids in spheroidal state, C, 612. 
 
 lowest observed, C, 462, 665; E, 744; 
 J, 238; G, 211. 
 
 mean, E, 950; J, 864. 
 
 measure of, N, 199. 
 
 monthly variations in, B, 662 ; E, 951. 
 
 remarkable, E, 744; J, 238. 
 
 and specific gravity, J, 94. 
 
 standard (France), D, i, 27, note. 
 
 table of, of some points of peculiar in- 
 terest, A, xv, 431; B, 565; D, I, 78. 
 
 upon what dependent, L, 111. 
 Tempering of bronze, copper and glass, 
 
 C, 212; E, 178. 
 metals, A, m, 395; C, 
 211; E, 178; J, 66, 
 68. 
 
 steel, A, vi, 166, and xv, 
 70;D,il, 888;E,178; 
 G, 27; compare An- 
 nealing. 
 
 Tenacity, B, 73; C, 203; E, 100; E, 
 170 ; F, 42, 53 ; G, 26 ; I, 70 ; J, 3, 66. 
 means of measuring, C, 202. 
 of metals, etc. (tables), C, 207; D, n, 
 
 667; E, 100; E, 170. 
 Tension, E, 252; J, 110. 
 changes density, E, 169. 
 electric, see Electric tension, 
 and temperature of vapors, formulae 
 
 for, C, 686. 
 volume of vapors, formulae for, C, 
 
 688. 
 
 of vapors, B, 609; C, 572, 588,638; 
 D, I, 241 ; E, 671 ; I, 
 227; J, 272-279. 
 limit of the, I, 227. 
 maximum, E, 621. 
 Thau ma trope. A, xvi, 131; E, 497; 
 
 E, 488; J, 625. 
 Theodolite, A, xv, 420 ; J, 4. 
 Theory, E, 3; G, 10; J, 2. 
 Thermal effects of air in motion, L, 43. 
 equilibrium, C, 463. 
 unit, A, IX, 19; D, I, 139. 
 Thermobarometer, J, 285. 
 Thermochrosy, A, vi, 450; E, 688; 
 
 E, 646; J, 354. 
 Thermo-dynamic unit, A, ix, 21. 
 
 electricity, see Electricity, thermo. 
 Thermo-electric battery, F, 262; see 
 Battery, 
 thermo- 
 electric, 
 chemical ef- 
 fects of, D, 
 I, 410; 
 compared 
 with yol- 
 taic, D, i, 
 409. 
 currents, see under 
 
 Electricity, 
 multiplier, B, 641; F, 
 
 261. 
 order of the metals, 
 
 D, i, 409, table, 
 pile, E, 521 ; F, 262 ; 
 L, 14, 30; in rela- 
 tion to radiant heat, 
 L, 265. 
 
97 
 
 Thermo-electric pile, used differen- 
 tially in researches on radiant heat, 
 H, 730; L,344. 
 rotation, F, 262. 
 
 Thermography, F, 380; K, 58. 
 
 Thermomagnetic power of bismuth, 
 
 F, 261; H, 731. 
 Thermometer, A, ix, 16, xv, 427 ; B, 
 
 585; D, I, 174; E, 492; E, 567; 
 
 G, 233; H, 731; I, 187; J, 229; N, 
 200. 
 
 air, C, 533, 536, 455; D, I, 170; E, 
 
 507; E, 587; F, 362; G, 236; J, 
 
 253,258; L, 318; formula for, C, 
 
 536-539 ; is uninfluenced by heat 
 
 that has passed through glass, L, 
 
 318 ; Regnault's, C, 534. 
 alcohol, A, xv, 430; C, 451; E, 506; 
 
 E, 575; I, 192; J, 235. 
 Breguet's metallic, A, xv,430; C,504; 
 
 E, 515; F, 364. 
 bulb, formula for size of, C, 446. 
 calibration of a, A, xv, 429 ; C, 443 ; 
 
 H, 732; J, 229. 
 
 Celsius's, see below, centigrade, 
 centigrade, A, iv, 650, xv, 427; B, 
 
 688; 0,436; E, 570 ; J, 232; L, 
 
 106. 
 construction of, A, xv, 428; C, 433, 
 
 442; E, 495; E, 568; G, 234; 
 
 H, 732; I, 188; J, 230; L, 105. 
 conversion of degrees on one scale into 
 
 those on another, A, xv, 429; C, 
 
 439; D, m, 811; E, 499; E, 
 
 571; F, 364; H, 734. 
 degrees of, J, 232. 
 differential, A, xv, 430; B, 540; D, 
 
 I, 171; E, 587; F, 362; I, 193; 
 
 J, 236; N, 201. 
 
 different forms of the, D, i, 174. 
 displacement of the zero point, see be- 
 
 lovv, zero point. 
 electric, J, 670, 709, see Battery, 
 
 thermo-electric and Galvanometer. 
 Fahrenheit's, A, xv, 42V; B, 488; C, 
 
 435; L, 106. 
 
 filled with various liquids, C, 451. 
 filling of a, A, xv, 428; E, 495. 
 fixed points of, C, 433; E, 497. 
 13 
 
 Thermometer, formula for the conver- 
 sion of degrees, F. into R. and C., 
 F, 363. 
 
 graduation of, A, xv, 429 ; C, 443 ; D, 
 I, 171; E, 500; E, 569; F, 362; 
 G,234; H, 732; 1,188; J, 230. 
 
 Green's, A, xv, 431. 
 
 history of, A, xv, 427; E, 508. 
 
 Howard's, E, 587. 
 
 indications furnished by the, E, 493. 
 
 Kinnersley's, E, 852; J, 670; N, 
 304. 
 
 Leslie's differential, B, 541; E, 509; 
 E, 587; F, 362; I, 195; J, 236. 
 
 limits of the mercurial, A, xv, 428; 
 E, 505; E, 574; J, 235. 
 
 de Lisle's, A, xv, 428 ; Matthiessen's, 
 J, 236. 
 
 maximum and minimum, A, xv, 430; 
 C, 452; E, 511, 513; E, 578; 
 H, 738; J, 237. 
 
 metallic, A, xv, 430; C, 504; E, 
 515; E, 580; F, 364; J, 237; N, 
 202. 
 
 mercurial, C, 432; F, 363; G, 234; H, 
 731; with arbitrary scale, C, 446 ; 
 calibration of, C, 443 ; H, 732 ; 
 change of zero point of, C, 441 ; 
 comparison of different, C, 439 ; H, 
 734; construction of standard, C, 
 442; defects of, A, xv, 429, 430; 
 C, 486; I, 192; filling and gradu- 
 ation of, C, 433 ; observations 
 with, how corrected, C, 448; size 
 of bulb of, C, 448. 
 
 metastatic, E, 514; E, 579. 
 
 method of making, see construction of. 
 
 mounting of, E, 501. 
 
 Negretti & Zambra's maximum, A, 
 xv, 431; C, 453; E, 512; E, 
 578. 
 
 Phillip's, A, Xv, 431. 
 
 principle of graduation of, D, I, 171. 
 
 relative advantages of mercurial and 
 alcoholic, I, 192. 
 
 Reaumur's, A, xv, 428; B, 488; E, 
 570; G, 235; J, 238; L, 106. 
 
 rules for using a, I, 193. 
 
 Rumford's differential, I, 194. 
 
98 
 
 Thermometer, Rutherford's maximum 
 and minimum, A, xv, 430; C, 452; 
 E, 511;E, 578. 
 Saxton's deep sea, E, 516; E, 
 
 581. 
 scales of, A, xv, 427; C, 435; E, 
 
 498; I, 189; J, 232. 
 self-registering, E, 578. 
 sensibility of, E, 504; E, 572; J, 
 
 235. 
 
 spirit, see above, alcohol, 
 standard points in, see above, fixed 
 
 points. 
 
 tests of, E, 572. 
 tubes, E, 494. 
 Walferdin's maximum, C, 454; E, 
 
 513; E, 578. 
 water, C, 438. 
 weight, J, 250. 
 
 zero point, displacement of the in the 
 mercurial, A, xv, 430; C, 441; E, 
 502; J, 234. 
 Therm o me trie observations, formulae 
 
 for correcting, C, 449. 
 scales, A, xv, 427; C, 436; E, 496; 
 
 I, 189. 
 
 centigrade, A, iv, 650. 
 conversion of the different into one 
 another, A, xv, 429; C, 436, 446; 
 E, 499. 
 
 various, D, I, 172. 
 
 Thermo multiplier. A, xv, 427; C, 
 457; D, I, 410; E, 588, 942; F, 
 380. 
 
 Thermophone, see Trevelyan's instru- 
 ment. 
 
 Thermoscope, Leslie's, C, 456; Rum- 
 ford's, E, 510; E, 587; C, 457; 
 Sanctorius's, C, 456. 
 Thermotics, A, ix, 15 ; F, 359. 
 Thunder, A, x, 627; B, 617; D, i, 312; 
 E, 1092; E, 989; G, 393; I, 
 423 ; J, 856. 
 
 house, A, x, 527; F, 208. 
 storms, E, 1093; E, 988; G, 394. 
 Tidal wave, K, 241, 291 ; velocity of 
 earth's rotation diminished by, L, 
 440. 
 
 Tides, A, xv, 469; G, 32; H, 740. 
 atmospheric, A, xvi, 471. 
 effect of on earth's rotation, L, 439. 
 
 Timbre, E, 446; M, 117. 
 Time, A, IK, 21; C, 22; E, 167; E, 
 29 ; F, 92, 95 ; H, 761 ; J, 9, 10 ; K, 
 17, 360. 
 
 is an essential element in all phenom- 
 ena of movement or change, A, ix, 
 21; K, 17.860. 
 
 exchanged for power, F, 92, 95. 
 measure of, C, 22 ; E, 167 ; H, 741 ; 
 necessity of its early measurement, 
 K, 320. 
 
 origin of the idea, C, 22. 
 units of, C, 22. 
 
 Tone, E, 444; E, 363; G, 195; J, 193, 
 changed by echo E, 355. 
 differential, J, 199. 
 Tones, wherein different from noises, B, 
 
 222; F, 138. 
 
 Tongueing in carpentry, G, 117. 
 Tonometer, M, 131. 
 Tonic, J, 193. 
 
 Toothed wheel of Savart, E, 441. 
 Top, spherical, N, 103. 
 Tornado, A, xvi, 390; E, 1060; E, 
 
 969; G, 287; 1,429. 
 Torpedo, see Electric fishes. 
 Torricelli'8 theorem, B, 179; E, 273; 
 
 E, 219; G, 169; F, 129; J, 163. 
 experiment, C, 275. 
 tube, E, 320; I, 111. 
 vacuum, B, 131; E, 261; F, 124; J, 
 
 122. 
 Torsion, C, 192; E, 48; E, 166; H, 
 
 742; J, 65. 
 
 balance, see Balance, torsion, 
 elasticity of, C, 191; E r 165; J, 66; 
 
 N, 20. 
 
 laws of, E, 166. 
 Touchstone, I), n, 1054, note. 
 Toughness of metal lost by continued 
 hammering, etc., A, xv, 138; 
 lost by drawing to wire, A, xvi, 
 493. 
 
 Tourmaline, J, 553. 
 Tourniquet, hydraulic, J, 167. 
 Trade winds, A, xi, 417, xv, 699; B, 
 
 582; D, I, 194; G, 283; L, 18. 
 Trajectory, A, xi, 319. 
 Transit circle, A, xv, 575. 
 Traiislucency, A, x, 515; B, 253; J, 
 415. 
 
Transparency, A, x, 515; B, 253; D, i, 
 122; E, 719; F, 278; G, 294; I, 
 261; J, 3, 415; L. 307, 321. 
 Transparency, cause of, L, 307. 
 not a test for diathermancy, L, 321. 
 not perfect, D, i, 122. 
 Transparent bodies, E, 719; F, 278; 
 
 I. 261. 
 Transpiration of gases and vapors, C, 
 
 417; D, i, 84-87. 
 
 Transposition in music, E, 374. 
 Trevelyan's instrument, F, 148; L, 112, 
 115, 142, 143; cause of the vibra- 
 tions of, L, 115, 142, 143. 
 Trimorphism, E, 94. 
 Trompe, A, in, 381. 
 Trough mercurial, see Pneumatic 
 
 trough. 
 
 Tubes, strength of, E, 172. 
 Tunica scelorotica, B, 298. 
 Tuning-fork, E, 460; E, 377; I, 
 
 172; J, 195; M, 102. 
 interference of sound 
 
 about a, M, 272. 
 nodes and overtones, M, 
 
 139, 157. 
 vibrations of, M, 58-60, 
 
 102, 137. 
 Turbine, A. xv, 643, xvr, 282; B, 186, 
 
 189,190; E, 231; I, 76; J, 168. 
 Twilight, A, xv, 681; C, 314. 
 Twining's ice machine, E, 681. 
 Twinkling, G, 338. 
 Tympanum, B, 249; E, 480; E, 
 
 393; G, 202. 
 Typhoon, A, xvi, 391. 
 
 tldometer, B, 600. 
 Umbra, E, 729; E, 411. 
 Uudulation theory, B, 327; G, 293; F, 
 
 275; H, 751; L, 263. 
 Undulations of air, E, 411; E, 331; 
 
 F, 134. 
 interference of, F, 
 
 134. 
 
 reflection of, F, 134. 
 circular, E, 400. 
 of the Ether, F, 275; H, 752. 
 of elastic fluids, E, 330; F, 118, 134. 
 interference of, F, 120. 
 length of, J, 174. 
 
 Undulations of light, see Light. 
 
 in liquids, E, 319, 320; E, 401. 
 
 in ocean, E, 329; E, 410. 
 
 origin of, E, 380; E, 299. 
 
 phases of, E, 384; E, 304. 
 
 progressive, E, 381; E, 300, 320; 
 in liquids, E, 401. 
 
 reflection of, F, 119. 
 
 sonorous, see Sonorous. 
 
 of a sphere of air, E, 412. 
 
 stationary, E, 302. 
 
 transmission of, F, 121. 
 
 transverse, A, x, 518. 
 
 of the waters of the globe, E, 410. 
 Uudulatory hypothesis, B, 327; F, 275; 
 G, 293; H, 751; L, 263 ; -compare 
 Light. 
 
 Uniform motion, B, 148; E, 30. 
 Unipolar bodies, F, 204. 
 Unison, E, 447; E, 364; G, 195. 
 Unit of Force, etc., see Force, Heat, etc. 
 Jacobi, J, 820. 
 
 jar, D, i, 295; F, 201. 
 Unorganized being?, growth of,E, 52. 
 Upsetting of high carriages, G, 50. 
 
 Vacuum, F, 122; G, 168. 
 
 in centre of ice flowers, L, 124. 
 extent of that formed by air pump, J, 
 146; by Sprengel's pump, J, 153. 
 fall of bodies in, J, 50. 
 formation of vapors in a, E, 620; E, 
 
 668. 
 
 heat radiated in a, J, 327. 
 not yet obtained, K, 134. 
 pans, E, 633. 
 
 passage of heat through, L, 258. 
 reflection in a, J, 335. 
 Torricellian, E, 261; F, 124; J, 
 
 122. 
 
 vapors formed in, E, 620; E, 668. 
 Values of fuels, E, 715. 
 Valves, G, 182. 
 
 (steam), A, xv, 50, 62. 
 
 Corliss's, A, xv, 54. 
 slide, N, 214. 
 
 safety, G, 258 ; J, 81, 286. 
 in the veins of animals, A, xvi, 45. 
 Vapor absorbs those rays of heat which 
 
 it emits, L, 426. 
 of alcohol, volume of, D, I, 233. 
 
100 
 
 Vapor, aqueous, ) Sfie y of water 
 in atmosphere, > 
 engines, A, xv, 58. 
 
 of ether, elastic force under great pres- 
 sures, D, i, 255. 
 formation of, B, 498. 
 of metals, spectra of, L, 424, et seq. 
 phenomena attending production of, 
 
 L,172, 
 production of consumes heat, L, 168, 
 
 206. 
 of water absorbs same class of heat 
 
 rays as water, L, 408. 
 absorption of heat by, in air 
 obtained from various 
 places, L, 398. 
 action of upon radiant heat, 
 
 L, 391, etseq. 
 amountj^of in the -^atmos- 
 
 phere, G, 269; L, 390. 
 Arago & Dulong's experi- 
 ments ^on g the tension of, 
 C, 575. 
 
 in the atmosphere, A, n, 308, 
 V, 864; 
 B, 689; 
 
 F, 873; 
 
 G, 239. 
 determina- 
 tion of, 
 D, n, 
 454. 
 
 elasti city 
 of, F, 
 373. 
 
 cause of its copious precipi- 
 tation In the tropics, L, 
 401 ; in England, L, 189. 
 condensation of, by moun- 
 tains, L,' 
 40. 
 
 in tropics, 
 its cause, 
 L, 401. 
 condensed] by rarefaction of 
 
 air, L, 45, 46. 
 definition of, L, 389. 
 decrease of in higher re- 
 gions of the atmosphere, 
 ^ 401. 
 
 Vapor of water, deposition of in atmos- 
 phere, A, vi, 432. 
 effect of its removal from 
 
 the atmosphere, L, 405. 
 elastic force of the (table), B, 
 503; D, 
 m, 818. 
 under great 
 pressures, 
 D, I, 255. 
 influence on climate, J, 843; 
 
 L, 189. 
 
 less in the higher atmos- 
 phere, L, 401. 
 precipitated by rarefaction 
 
 of the air,$L, 46. 
 precipitation of less East of 
 
 Ireland, L, 190. 
 quantity of given off by the 
 body, E, 692; E, 719. 
 tension of the (table), D, in, 
 
 813. 
 formula for, C, 
 
 671-581. 
 use of in English climate, L, 
 
 189. 
 Vaporization, E, .619, 709 ;iE, 667; 
 
 1,223; J, 269. 
 
 expansion of fluids during, F, 371. 
 latent heat of, B, 639; C, 604; D, 287, 
 
 879. 
 temperature and limits, E, 624 ; E, 
 
 672. 
 
 Vaporous condition of matter, L, 75. 
 Vapors, J, 269. 
 
 absorption of heat by,M, 352; L (ta- 
 ble), 368. 
 and emission of heat by, 
 
 L, 386, 426. 
 
 absorptive powers of, J, 358. 
 ascent of, F, 67. 
 Cagniard de Latour's experiments on, 
 
 C, 601; D, I, 256; J, 285. 
 density of, E, 693. 
 
 Dumas' method of finding, 
 
 J, 307. 
 
 Gay Lussac's, J, 305. 
 dynamic radiation and absorption of, 
 
 L, 386. 
 elastic force of, G, 248; N, 210, 
 
101 
 
 Vapors, elasticity of, under intense pres- 
 sure (Latour's table), D, I, 256. 
 engines^ A, xv, 58. 
 
 experiments on the formation of va- 
 por in closed tubes, J, 285. 
 formation of, B, 498; at all tempera- 
 tures, G, 238. 
 consumes heat, L, 168, 
 
 206. 
 
 phenomena of, L, 172. 
 in a vacuum, E, 620; 
 
 E, 668; J, 270. 
 and gases, relations between, D, i, 251; 
 
 E, 688. 
 
 general properties of, H, 757 ; I, 105. 
 latent heat of B, 530; C, 604; J, 287, 
 
 379. 
 
 liquefaction of, E, 640; E, 685. 
 of metals, spectrums of, L, 424, et seq. 
 point of maximum density, D, I, 242 ; 
 
 tension, E, 669. 
 problems on the mixture of gases and, 
 
 J, 301. 
 
 saturated, J, 270. 
 
 specific gravity of, see Specific Gravity, 
 tension of, see Tension, 
 unsaturated, J, 271. 
 
 Variation of magnetic needle, B, 360; 
 
 E,788; 
 
 H, 760. 
 
 annual and 
 
 daily, E, 
 
 790. 
 
 chart of, E, 
 
 789. 
 
 Velocities, composition of, C, 28 ; J, 30. 
 parallelogram of, E, 34. 
 theoretical and actual, E, 144. 
 Velocity, A, xi, 319, 321; C, 23; E, 
 
 116,125; G, 63; 1,23; J, 12. 
 acceleration of, A, i, 60. 
 of aerial waves, E, 332. 
 
 aerolites and planets, L, 23. 
 direction of, J, 34. 
 of efflux, B, 180; J, 163. 
 electricity, see Electricity, 
 falling bodies, see Falling bodies, 
 fluids in narrow channels, F, 131. 
 formula for, J, 179. 
 of light, see Light. 
 of moving body how determined, G, 63. 
 
 Velocity orbital of some planets, L, 23. 
 ratio of, A, xr, 327. 
 relation of, to quantity of matter, E, 
 
 124. 
 of sound, see Sound. 
 
 streams, E, 283; E, 227. 
 uniform, A, XT, 319. 
 uniformly accelerated and r retarded, 
 
 A, xi, 319. 
 variable, A, xi. 319. 
 virtual, H, 765. 
 Vena contracta, A, ix, 415; F, 130; G, 
 
 150; J, 165; N, 145. 
 Ventilating shaft, E, 696 ; E, 723. 
 Ventilation, compare Air pipe, A, xvi, 
 208; 1), i, 193; E, 716; E, 695; 
 H, 765; G, 260. 
 of buildings, E, 695. 
 machines for, A, in, p. 381, 382. 
 necessity of, E, 718. 
 a practical problem, E, 722. 
 quantity of air required, E, 693 ; E, 
 
 720; H, 765. 
 
 of a room, best method, G, 264. 
 supply of fresh air for, E, 699. 
 Ventilators, E, 725. 
 Emerson's, E, 698. 
 Ventral segment. J, 166. 
 
 in strings, M, 96, 97. 
 Ventriloquism, E, 474; E, 391. 
 Verification, Borda's method, E, 520. 
 
 of laws of falling bodies, E, 72. 
 Vernier, E, 266; H, 768; J, 4. 
 Vertical line, J, 4. 
 Vibrating armatures, E, 1036 ; E, 
 
 931. 
 bars examined by polarized light, M, 
 
 168. 
 
 dams, A, vi, 223; E, 386. 
 longitudinally, divisions and overtones 
 
 of rods, M, 166. 
 rods, F, p. 79, 147. 
 Vibration, E, 299; J, 171, 414. 
 
 (sonorous) of air in tubes, E, 467; E, 
 379, 384; F, 147; M, 179, 213; 
 results of experiments, E, 468. 
 arc of, J, 33. 
 of bars, F, 78. 
 
 bells analyzed, M, 150, 158. 
 bodies having different tempera- 
 tures, L, 112, 142. 
 
102 
 
 Vibration, communication of. through 
 
 air, L, 261; to flames, L, 261. 
 of cords, B, 240; F, 79; E, 388; I, 
 
 . 173; laws of, E, 389; I, 173. 
 discs, L,260; M, 147, 158. 
 effects of, on matter, F, 42. 
 of elastic plates, E, 392. 
 
 fluids, F, 118. 
 
 forms of, E, 387; E, 307; F, 79, 81. 
 of heated metals, L, 114; M, 110. 
 isochronous, A, xi, 324; E, 383; E, 
 
 303; F, 80. 
 
 laws of, M, 111, 113, 125, 255. 
 Lissajous's way of studying, J, 217, 
 
 222; M, 307. 
 
 longitudinal, F, 81; M, 159, 212. 
 measurement of, J, 185. 
 mechanical power of, D, i, 121. 
 of membranes, E, 398, E, 318; J, 
 
 216. 
 nodal points, F, 80. 
 
 the organs of, M, 209. 
 paths of, F, 81. 
 of pipes, M, 180-182. 
 paths of, F, 81 ; E, 311. 
 phases of, F, 80. 
 planes of, F, 143. 
 of planes, laws of, E, 395, 
 
 plates, E, 392, E, 312; M, 144; 
 
 N, 194. 
 
 laws of, E, 396; E, 315. 
 progressive, F, 79. 
 rate of, found by the syren, M, 68. 
 
 and pitch of note, E, 451 ; E, 
 
 369; J, 185, 196; M, 67. 
 representation of, on smoked glass, M, 
 
 59. 
 
 resolution of, E, 850; E, 644. 
 of rods, E, 390; E, 310. 
 fixed, F, 147. 
 
 at both ends, M, 135, 
 
 128, 157. 
 one end, M, 129, 157, 
 
 163. 
 free at both ends, M, 135, 157, 
 
 164. 
 
 ropes, F, 79. 
 solids, F, 79; E, 386. 
 sonorous, F, 138. 
 of sounding disks, L, 260. 
 stationary, F, 80. 
 
 Vibration of strings, see Strings, B, 240; 
 E, 388, 389; E, 308, 309; F, 79; 
 I, 173. 
 
 sympathetic, M, 321. 
 theory of, B, 326. . . 
 transverse, F, 81, 143: I, 173. 
 of a tuning fork, M, 58, 60, 137. 
 velocity of, F, 81. 
 verification of the laws of, 1, 174. 
 made visible, M, 139. 
 of water falling over dams, A, vi, 223. 
 Vibrations corresponding to notes, E, 
 
 451,452; F, 142,144. 
 produced by contact of bodies of dif- 
 ferent temperatures, L, 112, 142. 
 progressive, F, 79. 
 sonorous, E, 451, 452; F, 138, 143, 
 
 147. 
 
 stationary, F, 80. 
 view of, F, 144. 
 superposition of, M, 258. 
 Vibratory movements, nature of, G, 188. 
 Victoria tubular bridge, E, 172. 
 Vinometer, J, 97. 
 Violin, M, 89. 
 Virtual foci, see Focus. 
 
 velocities, A, xi, 327; E, 190; E, 
 
 105. 
 Viscosity and limpidity, D, I, 65. 
 
 (apparent) of the magnetic field, L, 49. 
 test of, L, 214. 
 
 Viscous theory of ice, L, 198, 208, 214. 
 Visibility of an object, circumstances 
 
 favoring the, A, xvi, 129, 130. 
 extreme limit of distance of the, A, 
 
 xvi, 129. 
 Vision, A, xvi, 128; E, 468; F, 366; 
 
 G, 347. 
 
 adaptation of eye to distance in, J, 518. 
 binocular, A, xvi, 130, 131; B, 307; 
 
 E, 484; 1,353; J, 620. 
 cause of erect with an inverted image, 
 
 F, 356. 
 
 simple with two eyes, F, 356. 
 conditions of distinct, E, 785. 
 deceptions of, G, 357. 
 defects of, I, 352 ; N, 247. 
 direction in which objects are seen, I, 
 
 269. 
 
 distance of distinct, E, 788; J, 483, 
 518. 
 
L I B R A R Y 
 
 103 
 
 rxiVKiisrrv OF 
 CALIFORNIA. 
 
 Vision, double, A, xvr, 132; E, 793; 
 
 E, 483; G, 354. 
 limit of distinct, B, 309; I, 352. 
 mechanism of, I, 352. 
 monocular, A, xvi, 131. 
 seat of, F, 355. 
 
 single with two eyes, E, 792 ; F, 356. 
 Sturm's theory of, J, 519. 
 with one eye, A, xvi, 131. with two 
 
 eyes, A, xvi, 130, 131 ; I, 353. 
 Visual angle, A, xvi, 131; E, 783; E, 
 
 472; F, 294; G, 354; J, 516. 
 impressions, duration of, D, I, 123, E, 
 
 487. 
 require time, E, 798; E, 
 
 489. 
 power of microscope and telescope, 
 
 E, 507, 513. 
 
 rays nearly parallel, E, 789; E, 479. 
 Vis viva, A, xi, 325; C, 53; E, 128; E, 
 
 111; J, 38; K, 218, 263. 
 conservation of, J, 39. 
 Vital activity, characteristics of, K, 407. 
 of plants, purpose of, G f 
 
 215; K,418. 
 
 effects, crude explanations of, K r 401. 
 principle, K, 402, 420. 
 Vitality, E, 10 ; G, 214. 
 Vitreous body, J, 514. 
 
 fusion, J, 264. 
 Vocal apparatus of man T E r 469 ; E, 
 
 368. 
 
 chords, Muller's imitation of their ac- 
 tion, M, 197. 
 Voice, A, XIH, 169; E, 469; E, 387; 
 
 G, 201. 
 
 action oi hydrogen on, M, 9, 
 falsetto, the causes of the, M, 197. 
 mechanism of, E, 472 ; E, 389 ; G, 
 
 2,03. 
 organs of, B, 248; G, 201; M, 195; N, 
 
 196. 
 
 range of man's, E r 472; G r 200. 
 roughness of voice in colds, its cause, 
 
 M, 196. 
 
 sonorous waves of the human, M r 71. 
 Volatile liquids, J, 269. 
 Volcanoes, A, xvi, 142; B, 361. 
 
 loss of heat by, K, 310. 
 Volta's contact theory of the pile, B, 
 436; E, 1000; E, 863, 897; I, 433. 
 
 Volta's d^covery, orlf m of, E, 966; E, 
 
 863. 
 
 electrical lamp, E, 856. 
 electroscope, E, 846. 
 hailstorm, E, 842. 
 
 Voltaic action, chemical theory of, E, 
 1001 ; contact theory 
 of, E, 1000; 1,433. 
 how interrupted and re- 
 newed, G, 409. 
 polarization and transfer 
 of elements during, D, 
 i, 324, and n, 1115; E, 
 1004. 
 arc or arch, D, i, 366; E, 984, 985; 
 
 heat of the, E, 988. 
 battery, see Battery; dissected, D, I, 
 
 346. 
 circle, difference between simple and 
 
 compound, E, 969, 981. 
 circuit, D, i, 317. 
 
 circuits simple and compound, D, i r 
 345; with one metal and two liq- 
 uids, D, i, 333-. 
 
 conduction, D, I, 359 ; effect of tem- 
 perature on in liquids, D, I, 365 ; 
 in metals, D, i, 359; measurement 
 of, D, i, 360. 
 couple simple, E, 969. 
 current, compare Electric current. 
 
 chemical action of the, D, i y 
 
 360. 368. 
 
 conditions requisite to the pro- 
 duction of, D, i, 335. 
 counter, D, i, 336. 
 defined, D, i, 326. 
 its direction, D, i, 328; de- 
 pends on direction of chem- 
 ical activity, E, 969. 
 energy of is proportional to 
 chemical ; activity, E, 1001. 
 influence of on a magnet, D, i r 
 
 318. 
 measurement of heat of, E, 
 
 988. 
 resistance to the, D, i, 343 ? 
 
 E, 983. 
 decomposition, E, 991 * T law of 
 
 chemical equivalents in, E, 992. 
 electricity, A, vn, 64, et seq.; E, 
 966; F, 210. 
 
104 
 
 Voltaic electricity, chemical action nec- 
 essary for the production of, E, 
 1001; compared with machine 
 electricity, F, 239; elementary 
 facts of, D, I, 316; laws and the- 
 ories of the disengagement of, E, 
 999, 1002 ; quantity needed to ef- 
 fect chemical decomposition, E, 
 1003. 
 
 induction, D, I, 330. 359. 
 ignition of charcoal, F, 224. 
 local action, D, I, 327. 
 pile, see Battery, 
 polarization precedes the current, D, i, 
 
 326. 
 
 spark, E, 985. 
 Voltameter, A, vn, 69; D, I, 352; E, 
 
 991; E, 889; F, 229. 
 Voltatype, D, n, 1124. 
 Volume (of bodies) change in the, E, 
 
 710; E, 664; J, 267. 
 definition of, C, 10; G, 12; J, 7. 
 determination of, C, 14; J, 86. 
 of a gas is augmented by heat, E, 
 
 608 ; L, 79, et teq. ; see Gases, 
 real, J, 7. 
 
 units of English, C, 13; J, 10, 11. 
 French, C, 17; J, 10, 11. 
 a vapor and its liquid, relation between 
 
 the, J, 308. 
 Volumeter of Gay Lussac, B, 98; C, 
 
 252. 
 
 Voussoir denned, N, 74. 
 Vowel sounds, formation of, M, 197. 
 synthesis of, M, 200. 
 
 Vulcanite, t. e., vulcanized caoutchouc, 
 D, in, 608. 
 
 Walferdin's thermometer, C, 454; E, 
 
 578; E, 513. 
 Walking, why hard for children to 
 
 learn, G, 52 ; advantage of turning 
 
 out toes, in, G, 50. 
 Warming, see Heating. 
 Warmth, sense of communicated by 
 
 bodies, F, 367. 
 
 Watches, A, v, 357, 360; G, 59. 
 W x ater, air in, G, 180. 
 
 amount of heat given off by, in cooling 
 1, L, 157. 
 
 Water, amount of work equal to heating 
 
 of 1, L, 160. 
 which would be boiled 
 by the total emission 
 of sun, L, 434. 
 
 anomalous expansion of, by heat, C, 
 527; D, I, 179; E, 604; F, 
 360; contraction, C, 552; K, 50; 
 L, 92. 
 boiled by friction, L. 24, 269, et teq. 
 
 why tasteless, G, 180. 
 boiling point of, see Boiling point, 
 capacity of for heat, G, 248. 
 cohesion of, increased by the removal 
 
 of gases, L, 125, et seq. 
 clock, see Clepsydra, 
 color of, L, 314. 
 column machine, B, 192, 195. 
 composition of, G, 123. 
 compressibility of, G, 124; F, 105; L, 
 
 154. 
 
 contraction of, L, 93. 
 decomposition of by electricity, B, 421 ; 
 D, II, 463, 1113; F, 227; G, 412; J, 
 692: by heat, D, n, 1107; F, 375. 
 density, F, 113. 
 
 maximum, A, ix, 433; C, 620- 
 626; D, I, 180; E, 542; E, 
 604; G, 231; I, 215; J, 
 252; L, 93; N, 203; his- 
 tory of the discovery of, C, 
 522; effect of salts on, C, 
 626 ; important bearings 
 of, C, 525. 
 effects of the high specific heat of, *L, 
 
 161. 
 its energy as a radiant in all 
 
 its states, L, 404. 
 when in a highly cohesive 
 
 condition, L, 126. 
 elasticity of, G, 124. 
 electrolysis of, see above, decomposi- 
 tion of. 
 
 evaporation of produces cold, L, 168. 
 expanded by heat, F, 360; L, 92; by 
 
 cold, L, 92. 
 
 expansion of as it approaches freezing, 
 C, 552; G, 231; K, 50. 
 by heat, law of its, C f 
 527 ; F, 360. 
 
105 
 
 Water, falls generate heat, L, 20. 
 
 of Keuss, thunder like tones 
 
 of, M, 211. 
 force exerted by in freezing, A, ix, 
 
 433 ; G, 232. 
 
 freezing of, A, ix, 433; B,534; C, 552, 
 549,654; D, I, 229; E, 
 618; E, 665; G, 231, 
 232 ; L, 169, 179. 
 by radiation, C, 654. 
 in vacuo (Leslie's method), 
 
 D, 1,229. 
 
 was formerly regarded as incompressi- 
 ble, L, 153. 
 
 from which air has been expelled, can 
 be heated far above the boiling 
 point, L, 126. 
 frozen by its own evaporation, B, 534; 
 
 D, I, 229; L, 169. 
 in red hot crucibles, L, 179. 
 hammer, J, 51 ; L, 125. 
 heating of, G, 244, 249. 
 high specific heat of, L, 158, 161. 
 inclination sufficient to give motion to, 
 
 G, 152. 
 
 index of refraction of, A, xvi, 260. 
 influence of, on climate, L, 160. 
 jets, E, 282. 
 
 effect of musical sounds on, M, 
 
 245. 
 
 latent heat of, L, 163. 
 level, E, 255 ; G, 136. 
 liquid absorbs the same rays as gas- 
 eous water, L, 407. 
 maximum density of, see above, dens- 
 
 ity. 
 
 mechanical value of combination, 
 condensation and congelation of, L, 
 164, et seq. 
 
 mode of heating, G, 221. 
 
 melting point of, influenced by pres- 
 siire, C, 550. 
 
 as a motive power, G, 155. 
 
 Oven, D, i, 221, and in, 6. 
 
 physical properties of that from which 
 air has been expelled, L, 125. 
 
 power defined, G, 88. 
 
 its power of sifting heat, L, 321. 
 
 pipes, how burst, L, 94; strength re- 
 quired for, G, 134. 
 14 
 
 Water, pressure exerted by, A, ix, 413 ; 
 E, 246 ; G, 130, 132 ; N, 124, 146. 
 rises in a pump how high, G, 182. 
 the seventh element of machinery, A, 
 
 ix, 412. 
 sound of falling how produced, G, 
 
 204. 
 
 specific gravity of, at different temper- 
 atures, F, 115. 
 heat of, how determined, L, 
 
 159. 
 spouts, A, xvi, 278; B,589; E, 1061; 
 
 E, 970; G, 287; H, 769; J, 842. 
 supply of towns, G, 134. 
 velocity of in pipes, how retarded, G, 
 
 151. 
 veins, are delicate sound reagents, M, 
 
 247. 
 vibratory motion hi, and its law, M, 
 
 255. 
 volume of at various temperatures, C, 
 
 526; E, 604. 
 waves, B, 209. 
 
 why it rises by suction, G, 169, 182. 
 wheels, A, xvi, 280; B, 189; E, 285; 
 
 H, 771 ; J, 168. 
 breast, A, xvi, 281; E, 230; 
 
 G, 157; N, 149. 
 horizontal, B, 189. 
 overshot, A, xvi, 281; E, 
 229; J, 168; G, 157; N, 148. 
 suspended, A, xvi, 282. 
 turbine, J, xvi, 282, xv, 643 ; 
 B, 189, 186; G, 158; E, 
 231; J, 168; I, 76. 
 undershot, A, xvi, 281 ; E, 
 230; J, 168; N, 148; G, 156. 
 weight of cubic inch of, A, xvi, 260 ; 
 
 D, i, 25. 
 
 comparative purity of, G, 123. 
 Wave, condensed, E, 331; N, 180. 
 length, E, 453; M, 63,69. 
 motion, M, 93-97, 255. 
 rarefied, N, 180. 
 Waves of air, A, xvi, 471; C, 286; E, 
 
 413; F, 134; H, 774. 
 expanding freely, E, 
 
 334; E, 415. 
 intensity and velocity of, 
 E, 413. 
 
106 
 
 Waves of air, interference of, E, 413 ; 
 
 E, 333; F, 134. 
 reflection of, E, 323; F, 
 
 134. 
 circular, reflected from a plane, E, 
 
 407. 
 
 combination of, E, 408. 
 depth of, E, 403 ; G, 153. 
 of ether, F, 276. 
 force of, A, in, 654. 
 in gases, N/179. 
 interference of, F, 120; in an ellipse, 
 
 E, 409. 
 
 length of sonorous, E, 453. 
 in liquids, B, 209;,.F, 118;*G,*153; N, 
 
 177. 
 
 optical delusions of, G, 153. 
 origin of, G, 153. 
 parts of, F, 80. 
 production of, E, 399; E, 319. 
 
 regular in[covered pipes, 
 
 B, 227. 
 reflection of, E, 119 ; E, 323 ; F, 119 ; 
 
 X, 183. 
 from an ellipse,'E, 405; 
 
 E, 324. 
 a parabola, E, 406; 
 
 E, 326. 
 in solids, N, 176. 
 of sound can pass each'other, F, 139. 
 
 defined, G, 190 ; M, 69. 
 stationary, E, .402; E, 321; M, 100. 
 transmission of, F, 121. 
 Weather and barometric variations, J, 
 
 125. 
 
 animals foretell changes in, G, 292. 
 glass, J, 126. 
 
 popular notions concerning, G, 291. 
 Weber's the, on wave motion, M, 97. 
 Wedge^A, xi, 327, 328; B, 51: E, 213- 
 215; E, 125, 126; F, 101; G, 106; 
 J, 25; N, 62. 
 
 applications of the, E, 215; G, 107. 
 how the power of increases, G, 107. 
 resistance to be overcome by, E, 214. 
 in the animal economy, F, 103. 
 Wedgewood's discovery, B, 344. 
 Weighing, C, 661; F, J>3; compare 
 
 Balance, 
 double, D, I, 26; J, 50. 
 
 Weighing machine, E, 201; E, 115. 
 by substitution, F, 94; see Weighing, 
 
 double. 
 Weighings taken in the air, correction 
 
 for, C, 268, 269; D, I, 32; J, 317. 
 Weight, B, 36; E, 37, 97, 106; F, 66, 
 67; G, 32; H, 778: I, 42; J, 23, 60; 
 N, 157. 
 
 absolute, C, 87; F,116; G, 38; form- 
 ula for, C, 87. 
 of a body in the air, C, 268; formula 
 
 for, C, 269. 
 
 definition of, E, 58; N, 41. 
 how determined for a given bulk of 
 any body when its specific gravity 
 is known, C, 87, 91; F, 116; G, 42. 
 is liable to variations, C, 89. 
 lifting of a, A, xi, 319. 
 a measure of quantity of matter, C, 
 
 88. 
 and measure standards of, B, 36 ; D, I, 
 
 25 ; see below, 
 relative and absolute, formula for, C 
 
 95. 
 mass, formulae for, C, 95, 
 
 M. 
 
 specific, and density, 
 formula? 
 for, C, 
 96. 
 
 sp e c ific 
 weig h t , 
 formula? 
 for, C,96. 
 
 specific, E, 99; G, 37. 
 unit of, C, 89. 
 
 varies, C, 89; E, 93; G, 32. 
 Weights and measures, A, xvi, 328; C, 
 94; G, 34; J, 
 94. 
 English, C, 11 ; G, 34, 
 
 36. 
 
 and French, 
 1), i, 24, in, 
 809. 
 
 French, C, 89,14; D, 
 m, 809; E, 100; 
 (i, 36. 
 
 Welding, A, xvi, 337; D, i, 56, and n, 
 672; G, 29. 
 
107 
 
 Wells, Artesian, A, n, 169; C, 233, 647; 
 E, 251; E, 204; G, 135: 1,89; 
 J, 83; N, 127. 
 Well, Passy artesian, A, '61, 42. 
 
 sweep, G, 159. 
 
 Wet clothing, why hurtful, G, 246. 
 Wheel, A, xvi, 383. 
 
 and axle, A, xi, 327; E, 202; E, 
 116; F, 97; G,99; N, 51. 
 differential, N, 51; crown, 
 N, 53 ; reaction, I, 76 ; 
 spinning, G, 101; spur, 
 N, 53. 
 
 Wheels, teeth of, G, 101; N, 127. 
 Wheelwork, analysis of, E, 204. 
 trains of, E, 203; E, 117; G, 101. 
 use of, N, 52. 
 
 Whirling table, N, 95, 97. 
 Whirlwind, A, xvi, 390; G, 207; E, 
 
 1060; E, 969. 
 Whispering galleries, E, 356; J, 183; 
 
 N, 185. 
 
 Wick of a lamp, how it raises oil, G, 145. 
 Will o' the wisp, B, 613. 
 Winch, G, 99. 
 Wind chest, J, 205. 
 Windlass, A, xvi, 466 ; G, 100 ; N, 50. 
 Windmill, A, xvi, 466. 
 Windpipe, G, 203. 
 Wind sail, see Air pipe. 
 Winds, A, xvi, 470; E, 968; F, 133; 
 
 G, 281: A, 779; 1,252. 
 causes of, A, xvi, 471; B, 58; E, 
 
 1055; G, 281; H, 780; I, 252. 
 consideration of, E, 957. 
 direction of, E, 965. 
 direction of changed by earth's rota- 
 tion, L, 183 ; by physical features 
 of the earth, G, 282. 
 Dove's law of rotation of the, A, xvi, 
 
 474. 
 effect of the spherical form of earth on 
 
 the, L, 187. 
 
 extinction of light of gas by, L, 63. 
 in high latitudes, B, 585. 
 force of, G, 282. 
 hot, E, 967. 
 law of rotation of, see above, Dove's 
 
 law. 
 lesser, cause of, L. 187. 
 
 Winds, motion of, A, xi, 417. 
 
 periodical, A, xvi, 473 : E, 1057 ; E," 
 
 963; H, 780; 1,253. 
 pressure of, B, 578. 
 
 produced by the heat of the sun, L, 182. 
 propagation of, E, 958. 
 regular, A, xvi, 471; E, 1056; E, 
 
 962; 1,253. 
 
 retardation of, A, xin, 414. 
 trade, A, xvi, 473; E, 1056; G, 283; 
 H, 780: L, 183, et se#.; upper and 
 lower, L, 183, et seq. 
 two currents of, on [Peak of Teneriffe, 
 
 L, 188. 
 
 of the United States, G, 285. 
 variable, E, 1058; E, 964; G, 284; 
 
 I, 253. 
 velocity of, A, xvi, 472; E, 1063; E, 
 
 961 ; G, 281 ; I, 254. 
 waves of, undulate vertically, A, xm, 
 
 414. 
 
 Wire-drawing of steam, A, xv, 54, 55. 
 longitudinal vibrations of a, M, 159, 
 
 163, 164. 
 
 vibrations of a red hot, M, 110. 
 Wood a bad conductor of heat, G, 218. 
 comparative value of for fuel, see Fuel, 
 hard, why difficult to ignite, G, 266. 
 snapping of, G, 19. 
 swells when wet, G, 148. 
 water in, G, 265. 
 weight of, G, 266. 
 
 Woolens, why used for clothing, G, 219. 
 Work, constant proportion between it 
 
 and heat, L, 53. 
 
 a gas may be expanded without per- 
 forming, L, 88. 
 interior, L, 155. 
 of machines, A, xi, 326. 
 rate of, J, 395. 
 
 unit of, A, XI, 326; G, 88; J, 38. 
 and vis viva, J, 38. 
 
 Working effort of various animals con- 
 trasted, A, xi, 327. 
 part 
 
 point 
 
 in machines, A, xi, 326 ; G, 92. 
 
 Woulfe's apparatus, C, 318-320; D, 11, 
 515 ; formula for, C, 319, 320. 
 
 Yard, C, 11-13; E, 17; J, 10. 
 
108 
 
 Yard, act of Parliament, concerning the, 
 0,11. 
 
 American standard, C, 13. 
 origin and history of, C, 11. 
 
 Zamboni's pile, B, 404; E, 873. 
 Zero, see under Temperature. 
 Zinc, amalgamated, E, 971. 
 bands in spectrum of, L, 424. 
 
 Zinc, local action of, E, 971. 
 Zincode defined, D, i, 370. 
 
 hotter than platinode in the voltaic 
 
 arc, D, i, 368. 
 Zodiacal light, A, xvi, 651; H, 786; K, 
 
 272; L, 68, 435-442. 
 probable cause of the, 
 L, 58, 435-442. 
 
General i 
 
 eatises on 
 philosophy'