PREFACE 



SECOND EDITION. 



i THE first Edition of these Lectures 

 having experienced a very extensive cir- 

 culation, the Proprietors have thought it 

 their duty to procure for the present 

 such an entire and cautious revision as 

 should render it still more worthy pub- 

 lic favour. 



Th whole of the first volume, and so 

 much^of the second as relates to Astro- 

 nomy, has been carefully examined by 

 a gentleman whose different works on 

 Mathematics and several departments of 

 Natural Philosophy have acquired a high 

 reputation. He has made numerous ad- 

 ditions and improvements, correcting 

 errors, and carefully introducing as he 

 went along, the most important dis- 

 coveries both of English and of con- 



