65 Mechanical Philosophy, [Chap. I. 



and by inventing a method of grinding them to 

 a true figure, which had been considered so diffi- 

 cult a problem by his predecessors, effected yet 

 greater improvements. Mr. Mudge was followed 

 by his countryman, Mr. Edwards, who also la- 

 boured, with some success, on the same instru- 

 ment ; but this has been since done much more ef- 

 fectually by Mr. Watson, an artist of London still 

 living. It was, however, reserved for the great astro- 

 nomer Herschel, to furnish the world with reflect- 

 ing telescopes of the most wonderful magnifying 

 power*. The extraordinary extent to which he 

 has carried his improvements, and the astonishing 

 discoveries which they have enabled him to make, 

 are too recent, and too well known, to make a de- 

 tail of them necessary here. 



During the period which we are considering, 

 mici'oscopes have been also carried to a very high 

 degree of perfection. In 1702 Mr. Wilson in- 

 vented one, of the single kind, which is still much 

 in use. In 1710 Mr. Adams presented to the 

 Royal Society another, also single, but of much 

 greater magnifying power. To which succeeded, 

 soon afterwards, the ingenious device of Mr. Grey, 

 of a temporary microscope, by means of a globule 

 of water. In 1738 or 1739, Mr. Lieberkuhn 

 made two very important improvements in micro- 

 scopes, by the invention of the Solar Microscope, 

 and that for viewing opaque objects. These were 

 followed by the reflecting microscope of Dr. Smith, 

 said to be superior to all others. Beside those 



* Tiie great Telescope of Herschel, 40 feet in length, is un- 

 doubtedly entitled to a conspicuous place among the wonder s. 



OF THE EIGHTEKNTH CKNTURY. 



