S Sabine, Sir E., 44. Safford, T. H., 202. Santini, G., 159. Savary, F., 30, 199. Satellites, 96, 107, 108, 112, 113, 115, 120, 121, 236. Saturn, 20, 21, 22, 97, 103, 108-113, 121, 135. Schaeberle, J. M., 93, 107, 191, 203. Scheiner, C., 44. Scheiner, J., 166, 174, 176. Schiaparelli, G. V., 82, 83, 84, 85, 86, 87, 91, 92, 114, 141, 143, 149, 201, 220, 224, 231, 235. Schjellerup, H., 180. Schmidt, J. F. J., 69, 70, 71, 72, 73, 104, 179, 180, 189. Schönfeld, E., 160, 179, 180, 188, 189. Schröter, J. H., 16, 65, 66, 67, 68, 69, 70, 74, 81, 82, 84, 85, 86, 87, 97, 99, 153. Schwabe, S. H., 18, 43, 44, 46, 55. Schwassman, A., 100. Secchi, A., 52, 54, 55, 60, 72, 90, 114, 141, 170, 171, 173. Secchi’s types of stellar spectra, 170, 171, 173, 174, 175, 189, 232. See, T. J. J., 201, 202, 236. Seeliger, H., 110, 195, 196, 202, 206, 224, 225. Serviss, G. P., 158. Sirius (α Canis Majoris), 151, 170, 173, 188, 202, 225. Slipher, V. M., 106, 114, 204. Sime, J., 27. Sola, J. C., 112. Solar cluster, 221, 222. Solar system, motion of, 26, 27, 167, 168. South, Sir J., 198. Spectroscopic binaries, 203, 204, 205. Spencer, H., 218. Spica (α Virginis), 204. Spörer, F. W. G., 45, 46, 54, 59. Star-catalogues, 159, 160, 161, 162. Star-clusters, 30, 31, 32, 206, 210. Star-drift, 164. Star-gauging, 36, 40, 41, 224. Stars, distance of, 150-158. Stars, distribution of, 35, 39, 40, 198-214. Stars, double, 28, 29, 30, 197-206. Stars, gaseous, 171, 174. Stars, proper motion of, 162, 163, 164, 165. Stars, radial motion of, 165, 166. Stars, temporary, 156, 182, 188-196. Stars, triple and multiple, 206. Stars, variable, 177-188. Stellar spectra, 169-176, 187, 189, 190, 191, 193, 194. Stellar universe, 35-42, 214, 215-226. Stereo-comparator, 100, 101. Stokes, Sir G., 50. Stone, E. J., 157, 160. Stroobant, P., 88. Struve, F. G. W., 3, 37, 38, 40, 42, 128, 151, 153, 200, 214, 215, 216, 218. Struve, H., 201. Struve, L., 27, 163, 167. Struve, O. W., 27, 110, 115, 120, 153, 156, 163, 200, 201. Stumpe, O., 167. Sun, 15, 16, 17, 40, 43-64, 65, 80, 81, 105, 125, 128, 170, 222, 228, 229, 230, 237. Swift, L., 81. Swift’s comet, 136. T Tacchini, P., 55, 86, 87. Taurus, 217, 221. Tempel, E., 210. Tennyson, 96. Tidal friction, 79, 87, 233, 234, 235, 236. Tisserand, F. F., 146. Todd, D. P., 122. Trans-Neptunian planet, 121, 122. Trouvelot, E., 86, 87. Tschermak, 148. Tulse Hill Observatory, 171. Turner, H. H., 194, 224. Twining, A. C., 139. U Upsala Observatory, 59. Uranometria Argentina, 160. Uranus, 11, 20, 22, 23, 97, 113, 114, 115, 118, 121, 135, 141, 230. Ursa Major, 162, 164. Ursæ Majoris (δ), 182. Ursæ Majoris (ξ), 199.