459 



Striive, Professor, on the rings of 

 Saturn, 63. On Halley's comet, 

 343. On the double stars, 3(58. 



Sun, the center of gravitation, 5, 6. 



, motion of, 8, 370. 



, magnitude of, 35. 



, eclipses of, 40. 



, parallax and distance of, 58. 



, mass of, 55. 



, rolatitm of, 61. 



, constitution of, 238, 239. 



, light and atmosphere of, 239. 



, spots on, 239. 



. heal of, 251, 252. 



Surfaces vibrating. 137. 



Svanberg, M., on the temperature 

 of space, 240. 



Sykes, Col., on the height at which 

 wheat grows, 264. 



Synodic revolution, 39. Note 112. 



Syren, 138. 



Syrup, physical properties of, 184. 



System, Solar, its stability, 21. 



, its motion, 6, 370. 



of Jupiter and his satellites, 27. 



of binary stars, 367. 



Syzygies, 88. Note 153. 



T. 



Tangent, 8 Note 38. 

 Tangential force, 15. 

 Temperature, internal, of the earth, 



67, 242. 



, stratum of mean, 241. 



of mines, 242. 



of wells, 243. 



of ocean, -J4.J. 



, superficial, of earth, 249. 



, eflfects of, on vegetation, 262. 



of space, 241. 



of the sun, moon, and planets, 



<*38etseq.. 

 Terrestrial latitude and longitude, 4. 



Note IT. 



meridian, 45. 



refraction, 150. 



imgnetism, 300, 333. 



Tessuiar system, 107. 

 Tetrahedron, 107. Note 164. 

 Theory of Jupiter's satellites, 26. 



of the moon, 33. 



of the tides?, 85. 



, atomic, 101. 



of sound, 122. 



of light, 148 et seq. 



of heat, 206. 



of electricity, 271 et sr.q. 



Thermal springs, 252. 



! Thermo electricity, 328. 

 ; Thermo multiplier, 329. 



Thunder, 132. 



Tides, theory of, 86. 



, semi-diurnal, 87, 



, semi-annual, 89. 



, effects of declination on, 90. 



Note 154. 



1 , neap and spring, 89. 



; .height of, 89, 91. 



, propagation of, 90. 



! , forces producing, 92. 



i at Batsha, 93. 



! Time, mean and apparent solar, 78. 



, mean and apparent sidereal, 



, , equinoctial, 81. 



, equation of, 78. 



| , square of, 36. Note 105. 



, divisions of, 79. 



Timocharis, his observations, 75. 



Torpedo, its electric properties, 299. 



Tourmaline, its properties, 173, 176, 

 17*. Note 199. 



Trade winds, 116. .. ".* 



Transit of Venus, 52. Note 131. 

 I Transmission of light, 171. . 

 ' of undulations, 123. 



of sound. 129. 



of heat, 208. 



Translation, 7. Note 3(5. 



Triangulation, 46. Note 125. 



Tropical revolution, 16. Note 69 

 j Tuning-fork, experiment with, 133. 



U. 



Undulations of water, 92, 93. Note 

 156. 



i of air, illustrated by those of a 



! field of corn, 123. 



. of air, 124. 



of ether, illustrated by those of 



a cord, 164, 186, 187. 



, small, 115. 



Undulatory theory of light, 161 et seq. 



, his distance from the sun, 53. 



, hia satellites, 32. 



Universe, 23, 381. 



V. 



Va'.z, M., on Halley's comet, 343. 

 On the nuclei of comets, 358. 



Vapor, -2-iS. 



Variation, a lunar inequality, 34. 

 i Note 104. 

 | of the compass, 300 ct seq. 



