BOOK II. 



HISTORY OF PHYSICAL SCIENCE IN ANCIENT 

 GREECE. 



INTRODUCTION. 



IN order to the acquisition of any such exact and 

 real knowledge of nature as that which we pro- 

 perly call Physical Science, it is requisite, as has 

 already been said, that men should possess Ideas 

 both distinct and appropriate, and should apply 

 them to ascertained Facts. They are thus led to 

 propositions of a general character, which are ob- 

 tained by Induction, as will elsewhere be more fully 

 explained. We proceed now to trace the forma- 

 tion of Sciences among the Greeks by such pro- 

 cesses. The provinces of knowledge which thus 

 demand our attention are, Astronomy, Mechanics 

 and Hydrostatics, Optics and Harmonics ; of which 

 I must relate, first, the earliest stages, and next, 

 the subsequent progress. 



Of these portions of human knowledge, Astro- 

 nomy is, beyond doubt or comparison, much the 

 most ancient and the most remarkable; and pro- 

 bably existed, in somewhat of a scientific form, in 

 Chaldea and Egypt, and other countries, before the 



