X PREFACE. 



his pupils, who does not indulge them in the 

 liberty of asking every question, the solu- 

 tion of which may have a tendency to in- 

 crease their fund of learning. Masters, by 

 acting thus, would undoubtedly be able to 

 judge in what respects their scholars were 

 most deficient; and could, of course, sup- 

 ply those deficiencies from their own know- 

 ledge, or from those helps which it may 

 naturally be supposed they have at hand. 



In the composition of these Lessons, I 

 have not scrupled to make a free use of the 

 Works of several of the most esteemed Au- 

 thors on Astronomy and Philosophy; and 

 if I have not always acknowledged where 

 the obligation lay, I may observe that such 

 alterations were made, or the extracts taken 

 in so detached a manner, as rendered it 

 nearly, if not absolutely, impossible. When 

 we remember that the improvements in these 

 sciences were gradual aod not effected by 

 one man, or by one age ; it must be allowed 

 that every production (except those which 

 boast of new inventions and discoveries) must 

 be principally a compilation; and the chief 



merit 



