INDEX. 



517 



Light, diffraction of, i!)4. Notes 193, 

 196, 197- 



of sun and moon, 274. 



of comets, 409. 



of fixed stars, 416. 



, action of, on retina, 198. 



, electric, 318. 



, polarization of, 200. 



, emanating theory of, 187, 192. 



, undulatory theory of, 187 et seq. 



, objections to the undulatory the- 

 ory of, removed, 220. 



, length and frequency of the un- 

 dulations of, 193. 



Lightning and its effects, 321 . 



, its velocity, 323. 



Line of no dip, 342. 



Lines of the second order, or conic sec- 

 tions, 6. Note 22. 



of perpetual snow, 291. 



, isothermal, 296. 



, isogeothermal, 289, 297. 



of equal and of no variation, 344. 



Longitude terrestrial, 7, 35, 48. Notes 

 11, 95. 



, celestial, 11. Note 47. 



of perihelion, 12. 



of nodes, 12. 



of epoch, 12. 



Lubbock, Sir John, completed the 

 theory of planetary motion, 73. 



Lunar theory, 3D. 



inequalities, 40. 



eclipses, 45. 



distance, 48. 



spheroid, 78. 



Lunar orbit, 39. 



, excentricity and inclination of, 



constant, 41. 



, nutation of, 9. 



Lyell, Mr., on the temperature of the 

 northern hemisphere, 84. His esti- 

 mate of the number of volcanic erup- 



tions, 282. 



M. 



Mackintosh, Sir James, a quotation 

 from his ' General View of the Pro- 

 gress of Ethical Philosophy,' 1. 



Magellanic clouds, 442, 443. 



Magnets, 348. 



Magnets, temporary, 358 et seq. 



Magnetic equator, 342. 



poles, 342. 



intensity, 343, 346. 



curves, system of, 345. 



storms, 347. 



induction, 349. 



force, 343, 350. 



fluids, 352. 



and electric forces, 352. 



Magnetism in general, 348. 



of different substances, 348. 



and electricity identical, 346. 



of the sun and planets, 381. 



, terrestrial, 341, 377. 



Magneto-electricity, 365, 369. 



Major axis of an ellipse. Note 23. 



of an orbit, 10. Note 42. 



secular motion of, 20. 



of planetary orbits invariable in 



length, 22. 



Malus, M., his discovery of the polar- 

 ization of light, 219. 



Mankind identical in species, 308. ' 



Marcet, M., on the temperature of an 

 Artesian well, 279. 



Marco Polo finds a difficulty in kindling 

 fire at great heights, 134 



Marine plants, their distribution, 305. 



Mariner's compass, 341, 344, 347. 



, variations of, 345 et seq. 



Mars, diameter of, 25. 



eclipsed Jupiter, 47. 



, parallax of, 61. 



, compression of, 66. 



, climate of, 275. ' 



Mass, 7- Note 27. 



of the sun and planets, 63. 



of Jupiter's satellites, 63. 



of the moon, 64. 



of Jupiter and the Jovial System, 



63. 



of comets, 403. 



Mathematical and Mechanical Sciences, 

 2. Note 2. 



Matter, proportion of, in any two pla- 

 nets, 63. Note 133. 



, the ultimate particles of, 114 et 



seq. 



the attraction of, 5. Note 5. 



, diamagnetic properties of, 369. 



, its diffusion through space, 452. 



