4 8 4 



INDEX 



Planets, how fertilised with life, 7 

 motion of, difficult to map, 385 

 motor force of, 208 

 orbits of, first correctly arranged 



by Coppernicus, 167 

 possible exchange of, 431 

 regarded as wandering stars, 27 



Plato, and Aristotle, their credulity, 



145 

 his adherence to a fixed earth, 



102 



inscription on his Academy, 57 

 on numbers, 52 

 on the Greeks, 98 

 quotation from his Crito, 458 

 wished to burn works of Demo- 



critus, 134 



Pliny, his Natural History, 10 

 on weather forecasting, 149 

 story of Democritus' power to 



raise the dead, 132 

 Plurality des Mondes, a work by 



Fontenelle, 386 

 Plurality of worlds, taught by 



Bruno, 180 

 Plutarch, on cessation of rotary 



force, 123 

 Plutocracy, always a dominant 



power, 149 



Polaris, a double star, 375 

 Polemic, Gassendi as a model of, 



222 

 Pole Star, distance from the earth, 



357 



Pons asinorum of intellectual de- 

 velopment, 5 



Pope, his epigram on Newton, 

 264 



Populace, the mind of, 150 



Porta, Delia, on force of steam, 



243 



Poseidonius, failure to accept Aris- 



tarchus' ideas, 116 

 measure of the earth, 76 

 on distance and diameter of the 



sun and moon, 94 

 on the tides, 122 



Precession of the equinoxes, cause 

 of, 167 



Preston, S. Tolver, on Lesage's 

 theory of gravitation, 454 



Prevost, fixes direction of the sun's 

 motion, 322 



Priesthood, Egyptian, their learn- 

 ing. 56 



Principia, Newton's, generally re- 

 jected by his contemporaries, 

 265 



Principia, of Descartes, its profound 



influence, 239 



of Newton, its origin and con- 

 tents, 253 



quotations from Newton's, 449 

 Printing-press, effect of its intro- 

 duction, 175 



Proctor, on cosmic structure, 391 

 Procyon, companion sun of, 372 

 Proportion, development of idea of, 



55 

 Protagoras, first of the atheists, 



141 



Protyl, 34 



Psalm, quotation from 52nd, 400 

 Ptolemaic system, Schiaparelli on, 



165 

 Ptolemies, court of, no Columbus 



at, 80 

 found the Alexandrian Library, 



152 



the, Greek kings, 57 

 Ptolemy, C., measure of the earth, 



79 



on measure of the sun, 92 

 on parallax of the moon, 87 

 Publishing, rapid growth of, in the 



fifteenth century, 175 

 Pulsilogy, an invention of Galileo's, 



198 



Pyramids, how measured, 55 

 Pythagoras, sacrifices a hecatomb 



in honour of his discovery, 



57 



taught revolution of the earth, 

 102 



QUERIES, quotation from one of 

 Newton's, 451 



RAMSAY, Sir William, on formation 

 of matter, 435 



Ranke, estimate of the number of 

 victims of religious persecu- 

 tion, 164 



Rationalism, its slight influence, 

 150 



Reflecting telescope, invented by 

 Newton, 257 



Reformation, early attempts before 



Luther, 176 



follows discovery of America, 163 

 the, might have been anticipated, 



157 



Refraction, Ptolemy on, 200 

 Religion in the Middle Ages, 156 

 rational, first taught by Bruno, 



182 



