458 



Ross, Capt. James, his determination 

 of the magnetic pole, 300. 



Rotation of the sun and planets, 7, 

 (iO, 61. 



of a fluid mass, 6, 43. 



oft lie earth, 58, (56. 



, invariability of the earth's-, 73. 



of the moon, 03. 



of Jupiter's satellites, 05. 



of Saturn's rings, 62. 



of winds, 118, 119. 



of water by electricity, 316. 



of magnets, 315. 



S. 



Sabine, Colonel, on the magnetic 

 equator, 302. 



Salt and sugar, their capillary at- 

 traction, 110. 



, rock, highly permeable to heat, 



209, 211. 



Satellites, 7. Note 32. 



of Jupiter, their theory, 26. 



of Saturn and Uranus, 32. 



Saturn and his rings, 62. 



Saussure, M., on the temperature of 

 mines, 242, 243. 



Savart, M., his experiments on the 

 sense of hearing, 126. On the 

 vibration of elastic bodies, 141 et 

 scg. 



Savary, M., the first who determined 

 the orbit of a binary star, 367. 



Schroeter, M., on the atmosphere of 

 Ceres, 238. 



Scoresby, Capt., on extraordinary 

 refraction, 151. On the tempera- 

 ture of the Arctic regions, 260. 



Seasons, variation of, 82. 



Secular variations, 13. 



of apsides, 16. Notes 66, 67. 



of eccentricity, 19. Note 70. 



of the eccentricity of the ter- 

 restrial orbit, 17. 



of nodes, 18 et seq. Note 73. 



of inclination, 20. Notes 72, 



75. 



in the obliquity of the ecliptic, 



21. Notes 79, 143, 148. 



of Jupiter, 19. 



of Jupiter's satellites, 27. 



of the moon, 35. 



Seebeck, Professor, on the maximum 

 point of heat in the solar spec- 

 trum, 215. 



Shell-fish, the weight thev sustain, 

 112. 



Shooting stars, 382. 



Sidereal day, 77. 



revolution, 16. 



astronomy, 361. 



I Sine of an arc or angle, 20. Note 76. 

 ; Sinus, distance and light of, 362. 



Smyth, Capt., measures the height 

 j of Etna, 113. His observations of 

 Y Virgiuis, 368. 



Snow, line of, perpetual, 251. 



Solar System, its motion in space, 5, 

 | 23, 370. 



! Solar spectrum, 154, 156, 192 214. 

 I Solar heat, quantity of, 2.52. 



I , distribution of, 253. 



1 Solstices, 81. Note 148. 

 1 Sothaic period, 80. 



Sound, theory of, 122, 123. 



, undulations producing, 124 



Note 156. 



| , intensity of, 125, 131. 



i , velocity of, 129. 



i , transmission of, 123 et seq. 



! , reflection of, 131, 132. 



, refraction and interference of, 



' 133. 



Sounds, musical, 134. 



, harmonic, 136. 



Space, 5. Note 21. 



, temperature of, 241. 



Speaking-machine, 147. 



Sphere, attraction of, 4. 

 i Spheroid, 4. Note 9. 



| , attraction of a, 4. Note 12. 



i Spring, 22. 



tides, 89. 



i Square of distance, 5. Note 23. 

 I of moon's distance, 5. 



of sine and cosine of latitude, 

 45. Note 123. 



! number and its root. Note 132. 



! Stability of system, 21. 

 I Stars, fixed, 361. 



, parallax of, 53. 



I , distance of, 53, 370. 



, distances of, known from the 



binary systems, 370. 



, number of, 361. 



, size of, 362. 



that have vanished, and new 

 stars, 363. 



, variable, 36-1. 



, their proper motions, 369,370. 



, double, 365. 



, parallactic motions of, 370. 



, binary systems of, and their 



orbits, 367 et seq. 



, color of, 374. 



- , clusters of, 374. 

 Steam, 227 ct seq. 



