[Roman figures refer to the chapters, Arabic to the articles.]
Thetis, viii. 160
Three bodies, problem of, xi. 228, 230–233, 235
Tidal friction, xiii. 287, 292, 293, 320
Tides, vi. 130; vii. 150; ix. 189; xi. 228–230, 235, 248; xiii. 287, 292, 293, 297, 320
Time, measurement of, i. 4, 5, 16. See also Calendar, Day, Hour, Month, Week, Year
Titan, viii. 154
Titania, xii. 255
Torrid zones, ii. 35
Total eclipse, ii. 43; vii. 145; x. 205; xiii. 301. See also Eclipses
Transit instrument, x. 218, 225 n
Transit of Mercury, x. 199
Transit of Venus, viii. 156; x. 202, 205, 224, 227; xiii. 281, 282, 284
Translations, iii. 56, 58, 60, 62, 66, 68
Transversals, v. 110 n
Trepidation, iii. 58, 62, 68; iv. 84; v. 112
Trigonometry, ii. 37 n, 47 n; iii. 59 n, 64 n, 68 n; iv. 74
Trivium, iii. 65
Tropical year, ii. 42
Tuttle's comet, xiii. 291
Twilight, iii. 69
Twinkling of stars, ii. 30
Two New Sciences (of Galilei), vi. 133, 134 n; viii. 152
Tychonic system, v. 105; vi. 127
Umbra (of sun-spots), vi. 124; xii. 268
Uniform acceleration, vi. 133. See also Acceleration
Uraniborg, v. 101
Uranometria Nova Oxoniensis, xiii. 316
Uranus, xii. 253, 254, 255, 267; xiii. 276, 288, 289, 297
Uranus, rotation of, xiii. 297
Uranus, satellites of, xi. 250 n; xii. 255, 267; xiii. 272, 295
Variable stars. See Stars, variable
Variation (of the moon), iii. 60; v. 111; vii. 145
Variation of elements or parameters, xi. 233 n, 236, 245
Variations, calculus of, xi. 237 n
Vega, iii. 64
Venus, i. 14–16; ii. 25, 26, 45, 47, 51; iii. 68; iv. 75, 81, 86, 87; v. 98, 100, 103; vi. 121, 123; vii. 136 n, 139, 142, 144; viii. 154; ix. 181, 185; x. 223, 227; xi. 235, 245; xii. 267, 271; xiii. 282, 297. See also the following headings
Venus, phases of, vi. 123, 129
Venus, rotation of, viii. 160; xii. 267; xiii. 297
Venus, transits of See Transits of Venus
Vernal equinox, i. 11. See also Equinoxes
Vernier, iii. 69 n
Vertical, ii. 33; x. 221; xiii. 285
Vesta, xiii. 294
Victoria, xiii. 281
Virtual velocities, xi. 237 n
Vortices, viii. 163; ix. 178, 195
Wave, wave-length (of light), xiii. 299, 300, 302
Weather, prediction of, ii. 20; vii. 136
Week, i. 16
Weights and Measures, Commission on, xi. 237, 238