20 CONTENTS. 



Page 



Sect. 3. Discovery of Aberration. — Bradley 464 



Sect. 4. Discovery of Nutation 465 



Sect. 5. Discovery of the Laws of Double Stars. — The Two Herschels 467 



Chapter VI. — The Instruments and Aids of Astronomy 



DURING THE NEWTONIAN PERIOD. 



Sect. 1. Instruments 470 



Sect. 2. Observatories 476 



Sect. 3. Scientific Societies 478 



Sect. 4. Patrons of Astronomy 479 



Sect. 5. Astronomical Expeditions 480 



Sect. 6. Present State of Astronomy 481 



*—¥ 



ADDITIONS TO THE THIRD EDITION. 

 Introduction 489 



Book I. — The Greek School Philosophy. 



The Greek Schools. 

 The Platonic Doctrine of Ideas. 491 



Failure of the Greek Physical Philosophy. 



Bacon's Remarks on the Greeks 494 



Aristotle's Account of the Eainbow 495 



Book II. — The Physical Sciences ln Ancient Greece. 



Plato's Timffius and Republic 497 



Hero of Alexandria 501 



Book III. — The Greek Astronomy. 



Introduction 503 



Earliest Stages of Astronomy. 



The Globular Form of the Earth 505 



The Heliocentric System among the Ancients 506 



The Eclipse of Thales 508 



