66 A CENTURY'S PROGRESS IN ASTRONOMY. 



profession at Hanover, and four years later he 

 was appointed " oberamtmann " or Chief Magis- 

 trate of Lilienthal "the Vale of Lilies" in 

 the Duchy of Bremen. At Lilienthal Schroter 

 erected a small observatory, and acquired in 1785 

 one of Herschel's 7 -foot reflectors. In 1792 

 the astronomer superintended the construction 

 of a 13-foot reflector, made by Schrader of Kiel, 

 who transferred his workshop to Lilienthal. With 

 these instruments the great work of Schroter was 

 accomplished. 



Schroter directed his powers of observation to 

 the study of the Moon. He originated the study 

 of the surface of the Moon, and founded the 

 branch of astronomy known as selenography, 

 or the study of the Moon's surface. The 

 foundations of this branch were laid in 1791 

 with the publication of Schroter's ' Seleno- 

 topographische Fragmented The astronomer 

 determined to make a comparative study of 

 the surface of our satellite, and before 1801 

 discovered eleven "rills" or clefts on the 

 Moon's surface, and recognised a large number 

 of craters. He likewise believed that he had 

 seen a lunar atmosphere, an observation of 

 which was made by him in February 1792. 

 Schroter seems never to have doubted what 

 Herschel and his contemporaries believed that 



