General Index 



439 



[Roman figures refer to the chapters^ Arabic to the articles.] 



Theory of the Universe (of Wright), 



xii. 258 



Thetis, vin. 160 

 Three bodies, problem of, xi. 228, 



230-233, 235 

 Tidal friction, xm. 287, 292, 293, 



320 

 Tides, vi. 130; vn. 150; ix. 189; 



xi. 228-230, 235, 248 ; xin. 287, 



292, 293, 297, 320 

 Time, measurement of, i. 4, 5, 16. 



See also Calendar, Day, Hour, 



Month, Week, Year 

 Titan, vin. 154 

 Titania, xn. 255 

 Tolelan Tables, in. 61, 66 

 Torrid zones, n. 35 

 Total eclipse, n. 43 ; vn. 145 ; 



x. 205 ; xm. 301. See also 



Eclipses 



Transit instrument, x. 218, 225 n 

 Transit of Mercury, x. 199 

 Transit of Venus, vin. 156; x. 



202, 205, 224, 227; xm. 281, 



282, 284 

 Translations, HI. 56, 58, 60, 62, 



66, 68 



Transversals, v. lion 

 Trepidation, in. 58, 62, 68 ; iv. 



84; v. 112 

 Trigonometry, 11. 37 , 47 n ; in. 



59 n, 64 n, 68 n ; iv. 74 

 Trivium, in. 65 

 Tropical year, 11. 42 

 Tuttle's comet, xm. 291 

 Twilight, in. 69 

 Twinkling of stars, n. 30 

 Two New Sciences (of Galilei), 



vi. 133, i34; vin. 152 

 Tychonic system, v. 105; vi. 127 



Umbra (of sun-spots), vi. 124 ; 



xii. 268 

 Uniform acceleration, vi. 133. 



See also Acceleration 

 Uraniborg, v. IOI 

 Uranotnetria Nova Oxoniensis, 



xm. 316 



Uranus, xii. 253, 254, 255, 267 ; 



xm. 276, 288, 289, 297 

 Uranus, rotation of, xm. 297 

 Uranus, satellites of, xi. 250 n ; 



xii. 255, 267 ; xin. 272, 295 



Variable stars. See Stars, vari- 

 able 



Variation (of the moon), in. 60 ; 

 v. Ill ; vn. 145 



Variation of elements or para- 

 meters, xi. 233 n, 236, 245 



Variations, calculus of, xi. 237 n 



Vega, in. 64 



Venus, i. 14-16; ii. 25, 26, 45, 

 47, 51; in. 68; iv. 75, 81, 86, 

 87; v. 98, 100, 103; vi. 121, 

 123; vn. 136 n, 139, 142, 144; 

 vin. 154; ix. 181, 185; x. 223, 

 227 ; xi. 235, 245 ; xii. 267, 

 27 1 ; xin. 282, 297. See also 

 the following headings 



Venus, mass of, xi. 235, 248 



Venus, phases of, vi. 123, 129 



Venus, rotation of, vin. 160; xii. 

 267 ; xin. 297 



Venus, transits of. See Transits 

 of Venus 



Vernal equinox, i. n. See also 

 Equinoxes 



Vernier, in. 69 n 



Vertical, n. 33; x. 221 ; xm. 

 285 



Vesta, xin. 294 



Victoria, xin. 281 



Virtual velocities, xi. 237 n 



Vortices, vin. 163; ix. 178, 

 195 



Wave, wave-length (of light) 

 xin. 299, 300, 302 



Weather, prediction of, u. 20 

 vn. 136 



Week, i. 1 6 



Weight, vi. 1 1 6, 130; ix. 180 



Weights and Measures, Com- 

 mission on, xi. 237, 238 



