Till. REFRACTOR AT DORPAT 127 



space than ever human being did before roe. I have 

 obeerved stars, of which the light Ukea two million* 

 of years to travel to this globe.' " The Church U a 

 telescope that looks, or should look, even farther into 

 pace and time. 



\\ chel was giving life and power to the 



refle* scope, Dollond's followers in thin country 



and Fraunhofer in Qermany were restoring the re- 

 fractor t<> the place from wl. ad been deposed 



finest refractor that, up to that 

 1 had ever seen was erected for Strove at the 



he Russian Govern m.-nt in Dorpat The 

 tube was 13 feet in length, and the object-glass was 



bei in diameter. The weight of til-- 

 whole was about 8000 Russian pounds. Of his first 

 look through it Struve says: "I stood astonished 

 before this beautiful inst undetermined which 



to admire most, the beauty and elegance of the work- 

 manfthip in its most minute parts, the propriety < 

 construction, the ingenious mechanism for moving it, or 

 the incomparable optical power of the telescope, and 

 the precision with which objects are defined. " l ii<- 

 was proud of his assistant He believed it to be the 

 equal of Herschel's 40-fect reflector, and it was certainly 

 far more easy to work. With its help he conti 

 the work Herschel began. It appears, however, that 

 Herschel sometimes used a parabolical glass mirror of 

 i focal length instead of the metal mirror, 2 avoiding 

 flection the colours due to refraction. This 

 e remembered to his credit 



Tmn. ii. 94. ' Phil. from, for 1808, p. 228. 



