600 



INDEX. 



Hero's fountain, 258, PI. 23. 



Herschel, 334, 335, 337, 342, 357, 382. 389, 390, 



391, 392, 393, 397, &99, 403, 404, 405, 406, 407, 



410, 421, 423, 424,461, 489, 490, 546, 589, PI. 31, 



33,39. 



Hessian bellows, 264. 

 Hevelius, 458. 

 Hiero, 184, 276. 

 High pressure engine, 2/2. 

 H igh water, 442. 



Hipparchus, 393, 402, 413, 451, 454, 455. 

 History of astronomy, 451. 

 History of hydraulics and pneumatics, 275. 

 History of mechanics, 180. 

 History of music, 315. 

 History of optics, 374. 

 History of terrestrial physics, 580. 

 Hoar frost, 555. 

 HOI1, PI. 23. 

 HOll's machine, 257. 

 Hoffmann, 489. 

 Hogshead, 95. 

 Hofiow beams, 108. 

 Hollow masts, 115. 

 Homogeneous medium, 321. 

 Hooke, 5, 76, 106, 123, 145, 147, 159, 190, 203, 



205, 256, 265, 278, 282, 377, 378, 382, 416, 430, 



458, 459, 460, 584, 585, PI. 6 ; b. 1635, d. 1703. 

 Hooke's counterpoise, 237, PI. 19. 

 Hooke's joint, 133, PI. 14. 

 Hoop, 26. 

 Hope, 569. 

 Horizon, I'l. 35. 

 Horizontal moon, 356, PI. 3u. 

 Horizontal range, 30, PI. 2. 

 Horizontal refraction, 346. 

 Horizontal scapement, PI. 16. 

 Horizontal surface, 197. 

 Horizontal watch, 150. 

 Horn, 314. 

 Hornsby, 392. 

 Horrox, 432. 



Horse, 102. Positions of a horse's legs, 37. 

 Horses, 167, PL 18. 

 Hour glasses, 144. 

 Howard, 425, 564. 

 Huddart, 140, 141, 382. 

 Human voice, 312. 

 Humboldt, 395. 

 Humidity, 553. 

 Humming top, 314. 

 Hunter's screw, 55, 160, 169. 

 Hurdy-gurdy, 312. 

 Hutton, 284. 

 Huygens, 34, 50, 146, 147, 190, 210, 279, 280, 347, 



349, 360, 361, 363, 3<>8, 371, 378, 379, 380, 382, 



391, 411, 433, 458; b. 1629, d. 1695. 

 Hydra, 566. 



Hydraulic air vessels, 257, PI. 23. 

 Hydraulic architecture, 235, 237, 238. 

 Hydraulic bellows, PI. 24. 

 Hydraulic forces, 241. 

 Hydraulic machines, 250. 

 Hydraulic measures, 243. 

 Hydraulicostatics, 228. 

 Hydraulic pressure, 46, 228, 279. 

 Hydraulic ram, 259. 

 Hydraulics, 195, 196, 210. 

 Hydrodynamics, 195. 

 Hydrometer, 236, PL 21. 

 Hydrometrical fly, 243, PL 22. 

 Hydrostatic balance, 235, PL 21. 

 Hydrostatic instruments, 235. 

 Hydrostatic parodox, 199. 

 Hydrostatic press, 170. 

 Hydrostatic pressure, 511. 

 Hydrostatics, 195, 196, 197, PL 19. 

 Hygrometer, 55.'i, 587, PL 41. 

 Hygrometry, 587- 

 Hypatia, 276. 

 Hyperbola, 477. 

 Hyperbolic fringes, PL 30. 

 Hypotheses of electricity, 507- 



Ibn Junis, 14?, 456. 

 Ice, 348, 442, 546, 582. 



348, 353, 3n> 



Idioelectrics. See electrics. 



Igneous meteors, 564. 



Ignis fatuus, 340. 



Illumination, 330. 



Illumination of the planets, PL 34. 



Image, 327, 329, PL 27, 28. 



Image on the retina, 351, 355, PL 30. 



Impenetrability, 467. 



Impenetrability of matter, 21. 



Impulse of a fluid, 46. 



Impulse of a jet, 229. 



Inanimate force, 69. 



Inclinations of the planetary orbits, 401. 



Inclined plane, 33, 54, PI. 4, 5, 17. 



Index, 76. 



Index of refraction, 323. 



Indian ink, 73. 



Indians, 452. 



Indivisibles, 28. 



Induced electricity, 512. 



Induction, 12. 



Inelastic bodies, 57, 59. 



Inertia, 17, 26, 39, 470. 



Inferior tides, 446. 



Infinites, 28. 



Inflammable bodies, 323. 



Ink, 76, 93. 



Insects, 575. 



Instinct, 352. 



Instruments. Musical instruments, 310. 



tical instruments, 328. 

 Insulated stars, 392. 

 Intensity of electricity, 527. 

 Intensity of light, 328. 

 Interception of light, 321. 

 Interception of sound, 294. 

 Interference of light, 364, 370. 

 Intermediate spring, 148. 

 Intermitting springs, 216. 

 Inundations of large rivers, 557. 

 Inverted pump, 257. 

 Inverted tide, 443. 

 Invisible girl, 294. 

 Invisible heat, 489. 

 Involutes of circles, PL 15. 

 Ionian school, 181, 453. 

 Ionic column, PL 12. 

 Iris, 351, 354. 

 Iron, 117, 174, 187, 531. 

 Iron filings, 534, 538, PL 41. 

 Iron wheelways, 167- 

 Irvine, 499, 500, 586. 

 Italian school, 181. 



Jack, PL 17. Kitchen jack, 137. 



Jacobi, 540. 



Jamaica, 547- 



Janson, 375, 376. 



Jars, 517. 



Jeaurat, 381 ; b. 1704, d. 1803. 



Jet, 211, 212, PL 20. 



Jet with a ball, 226. 



Jewelling, 148. 



Jew's harp, 314. 



Joggles, 129, PL 13. 



Joint focus, 327- 



Joints, 123, 128. 



Joints for beams, PL 13. 



Joints of stones, PL 11. 



Journal de Physique, 192. 



Journals, 191, 192. 



Juan, 284; b. 1713, d. 1773. 



Judgment of distance, 355. 



JUrgen, 187- 



Julian period, 429. 



Juno, 404, 424. 



Jupiter, 404, 422, 424, PL 33. 



Jupiter's satellites, 421. 



Jurin, 379, 589; b. 1680, d. 1750. 



Jussieu, 572, 586; b. 1699, d. 1777. 



Ka? stner, 282. 

 Kant, 391. 

 Keel, 248. 

 Keir's lamp, 227. 

 Kclland, 488, 506. 

 Kcmpe, 187. 



Op- 



