INDEX 



487 



Three bodies, problem of, 296 

 Tides, early observations of, 123 

 Kepler on, 189 

 Galileo on, 189 

 theory of, established by Newton, 



262 

 Time, ancient lack of an accurate 



measure of, 126 

 Torquemada, the number of his 



victims, 164 



Torricelli, discovery of the baro- 

 meter, 240 

 Toscanelli, encourages Columbus, 



1 60 



ideas of, 79 

 Tourbillons, or vortices, imagined 



by Descartes, 219 

 Trigonometry, its late development, 



146 



Triple star systems, 376 

 Tripoli, its library burnt, 154 

 Twentieth century, attains to a 



true cosmic, picture, 7 

 Tycho Brahe, famous star of, 



379 



his observations utilised by Kep- 

 ler, 1 86 



objections to Coppernican idea, 

 28 



on origin of comets, 271 

 Tyndall, his conception of material- 

 ism, 140 



littleness and greatness of man, 



39 

 Types of stellar arrangement, 376 



ULPTAN library, in Rome, 153 

 Uniformity, remarkable, of planet- 

 ary motions, 403 

 Universe, as a flower garden, 



Herschel's idea of, 410 

 as a cyclic process, 7 

 binding force of, 445 

 end of, 459 

 extent of, Coppernicus' ideas of, 



1 66 



Newcomb on limits of, 359 

 pictured as a gas, 429 

 Unthinkables, Democritus' choice 



of, 137 

 Uranus, discovered by Herschel, 



305 

 Urban VIII., inscription on his 



brother's tomb, 159 

 Urstoff, 34 

 Usher, Archbishop, date of creation, 



24 



VACUUM, limits of, obtainable, 429 



nature's horror of, 240 

 Vanini, torture and fate, 206 

 Vaucanson, marvels of mechanics, 



41.5 

 Vendelinus, estimate of the distance 



of the sun, 229 

 Venus, distance from the earth, 



356 

 phases of, discovered by Galileo, 



202 

 transit of, first observed by 



Horrox, 222 



Velocity, surface, of the earth, 317 

 Vinci. See Leonardo da Vinci 

 Virgil, quoted, 105 

 Virginia Reel, cosmos likened to a, 



43i 



Vives, Ludovicus, quotation, 72 

 Viviani, carries out Torricelli' s ex- 



rriment, 240 

 discovery of spectroscopic 

 " binaries, 374 

 Voltaire, a sincere deist, 298 

 his ironical inquiry, 435 

 introduces Newton to France, 



264 



tale of Micromegas, 44 

 Vortex ring theory, 219 

 Vortices, the foundation of Des- 

 cartes' system, 219 

 Voyages, extent of ancient, 355 



WALLIS, his treatise on gravity, 



254 

 Washington, George, mentioned, 



149 

 Weather predictions of Democritus, 



135 



Wheel, bacillus on the, 39 



Whewell, his History of Science, 10 



Williams, on methods of animal 

 reasoning, 9 



Wittenberg, the Athens of Ger- 

 many, 179 



Wollaston, maps, spectrum lines, 

 346 



Wordsworth, his " Mutability " 

 quoted, 400 



World formation, a mechanical 



process, 7 



image, difficulty of constructing 

 a, 3 



Worlds, the birth and death of, 

 401 



Wren, Sir Christopher, law of in- 

 verse squares, 298 



