

Figure io. — George Bassett Clark. Courtesy Lick 

 Observatory. 



director of the new Harvard College Observatory, was greatly impressed 

 with Clark's map and pointed out that he had plotted a star which had 

 escaped William Herschel with his 20-foot reflector. 28 Nevertheless, Clark 

 was dissatisfied with the definition and light-gathering power of his mir- 

 rors and, around 1 846, he began to figure lenses. Within a year he had 

 acquired enough knowledge of optics to perceive and locate, at a glance, 

 certain slight errors of figure in the 1 5-inch lens of the Harvard telescope. 

 This lens, made by the German firm Merz und Mahler, had cost $ 1 2,000. 

 The errors and the cost gave Clark the "hope and courage" he needed 

 to begin making refracting telescopes for sale. 2p 



28 Simon Newcomb, "The Story of a Telescope," Scribner's Monthly, vol. 7 ( 1873— 

 1874), p. 44. 



29 Alvan Clark autobiography, op. cit., p. 113. 



16 



