36 



To the union of scientific knowledge and practical 

 skill we are likewise indebted for that valuable in- 

 strument, the refracting telescope, which, for most 

 purposes, has superseded the reflector. In the con- 

 struction of this instrument, Dollond accomplished 

 what even Newton had given up as unattainable; the 

 result, not of mere ingenuity, but of that combination 

 of science with art by which ends are attained to 

 which we should never be led by any chance or ac- 

 cident. 



As I had occasion before to observe, the pro- 

 gress made in astronomy, navigation, geography, 

 and the kindred sciences, are due immediately to the 

 perfection of the instruments prepared by the me- 

 chanician ; but these instruments owe their perfec- 

 tion, if not their very existence, not to mechanical 

 skill alone, but to mechanicians whose minds are 

 deeply imbued with the principles of the science 

 for the advancement of which those instruments were 

 to be employed men who fully comprehended the 

 nature of the ends to be attained, and could them- 

 selves apply the instruments they had made, without 

 which knowledge they could not, in many instances, 

 have constructed them. It is to the philosophical 

 and mathematical makers of philosophical and math- 

 ematical instruments, that the several national ob- 

 servatories are indebted, in a great measure, for the 

 value of their observations. 



The application of chemistry to the arts, before al- 

 luded to, would probably afford examples of the value 

 of the alliance between science and the arts more nu- 

 merous than those furnished by mechanical philoso- 



