INTRODUCTION. 



IT is my purpose to write the History of some 

 of the most important of the Physical Sciences, 

 from the earliest to the most recent periods. I shall 

 thus have to trace some of the most remarkable 

 branches of human knowledge, from their first germ 

 to their growth into a vast and varied assemblage 

 of undisputed truths ; from the acute, but fruitless, 

 essays of the early Greek Philosophy, to the com- 

 prehensive systems, and demonstrated generaliza- 

 tions, which compose such sciences as the Me- 

 chanics, Astronomy, and Chemistry, of modern 

 times. 



The completeness of historical view which be- 

 longs to such a design, consists, not in accumulating 

 all the details of the cultivation of each science, but 

 in marking clearly the larger features of its forma- 

 tion. The historian must endeavour to point out 

 how each of the important advances was made, by 

 which the sciences have reached their present posi- 

 tion ; and when and by whom each of the valuable 

 truths was obtained, of which the aggregate now 

 constitutes a costly treasure. 



