508 



INDEX. 



Armature, a piece of soft iron connect- 

 ing the poles of a horse-shoe magnet, 

 367. 



Artesian wells, 279. 



Assyrians made use of the week of 

 seven days, 96. 



Astronomical tables, 66. 



, data for, 66. 



eras, 97- Note 147. 



Astronomy, physical, 3. 



of the Chinese and Indians, 99. 



Atmosphere, analysis and pressure of, 

 131. 



, the law of its density, 131. 



, the effect of heat on, 132. 



, the extent of, 133. 



, oscillations of, 134. 



of the moon and planets, 273. 



of the sun, 274. 



of comets , 402. 



Atomic weights, 121. 



Attraction of a sphere and spheroid, 5. ! 



of the earth and moon, 6. 



of the celestial bodies, 6. 



, universal, 7- 



, capillary, 127. 



, electrical, 314. 



, magnetic, 348. 



of electric currents, 361. 



Aurora, 329. 



agitates the magnet, 347. 



Axes, lunar, 73. 



, major, of planetary orbits inva- 

 riable, 22, 85. 



, connection of, with mean motion, 



22. 



Axis of rotation, 9, 74. Notes 34, 137. 



, principal, 86. Note 142. 



parallel to itself, 74, 89. 



of a pri sm , 201 . Note 1 99. 



of a telescope, 36. 



of a cone, 6. Note 22. 



, optic, 212. Note 202. 



of the earth's shadow, 45. 



B. 



Babbage, Mr., his theory of volcanic 



action, 285. 

 Bacon, 37. 

 Back, Capt., cold suffered by, 2/6. 



Bailly, M., on the lunar tables of the 

 Indians, 99. 



Baily, Mr. Francis, on the form of the 

 earth, 57. 



Barlow, Mr., on terrestrial magnetism, 

 377. 



Barometer, 131. 



Barometrical measurements, 133. 



Base, trigonometrical, 54. Note 125. 



Batsha, tides at, 110. 



Battery, Voltaic, 331. 



Bacquerel, M., his experiments and 

 opinions of electrical phenomena, 318. 

 His theory of atmospheric electricity, 

 320. His formation of crystals, 338. 

 His thermo-electric battery, 374. 



Bessel, Professor, his notice of the secu- 

 lar variation of the ecliptic, 92. 



Biela, M., discovers a comet, 395. 



Binary systems of stars, 416 et seq. 



Bissextile, or leap-year, 95. 



Biot, M., his ascent in a balloon, 134. 

 His experiments on sound, 152. On 

 circular polarization, 213. His theory 

 of electrical light, 318. Of terrestrial 

 magnetism, 377- On the disturbances 

 of terrestrial magnetism, 379. His 

 observations on the magnetic force 

 during his aerostatic expedition, 381. 



Birds, their dispersion, 308. 



Bonnycastle, Capt., his account of a 

 luminous appearance in the sea, 328. 



Bonpland, M., his botanical observa- 

 tions, 304. 



Botto, Professor, his experiments on 

 thermo-electricity, 375, 383. 



Bouguer, M., his mensuration of a de- 

 gree of the meridian at the equator, 

 54. 



Bradley, Dr., his discovery of nutation, 

 91. His tables of refraction, 173. He 

 mentions the two stars of y Virginis, 

 418. 



Brahmins employed the week of seven 

 days, 96. 



Brewster, Sir David, his discovery of 

 fluids in the cavities of minerals, 115. 

 His analysis of solar light, 180. His 

 law of the polarizing angle, 207. His 

 investigation of the temperature of 

 springs, 288. His estimate of the 

 temperature of the poles of maximu m 



