on the consideration of Michell's own 

 astronomical work it maybe convenient if 

 we take note of what were the actual per- 

 sonal relations of these two astronomers. 

 It is now clearly established that they 

 started quite independently of each other 

 in the actual construction and employ- 

 ment of the reflecting telescope. We do 

 not know when and under what con- 

 ditions the Rector of Thornhill began to 

 construct the large instrument which 

 ultimately became the property of Her- 

 schel, but it would appear that he had 

 made considerable progress, if he had not 

 completed it before 1781. Herschel did 

 not begin to study astronomy until 

 1773 when he was still actively engaged 

 in the multifarious duties of his musical 

 profession at Bath. In the following 

 year he began to grind specula 1 . After 

 six years, during which he worked la- 

 boriously with his telescope, he was able 



1 The Scientific Papers of Sir William HerscM, 

 vol. I, pp. xxxi-xxxii. 



92 



