THE MOON. 69 



parts during 1834-36. "The amount of detail," 

 wrote Proctor, " is remarkable, and the labour 

 actually bestowed upon the work will appear 

 incredible." The chart has neither been revised 

 nor superseded, and it remains to this day one 

 of the standard works on the subject. 



The chart was succeeded in 1837 by a descrip- 

 tive volume entitled ' Der Mond.' In this work 

 Beer and Madler did much for the progress of 

 lunar astronomy. Their observations led to a 

 change of opinion regarding our satellite's physical 

 condition. Herschel, Schroter, Olbers, and other 

 astronomers seem to have considered the Moon 

 a living world. Madler declared that it was a 

 dead world. He believed it to be destitute of 

 life of any kind, and the changes observed by 

 Schroter and other observers were put down 

 as illusions. 'Der Mond' was the end of 

 Madler's work in lunar astronomy, for, receiving 

 an appointment at Dorpat, he went there in 

 1846, and retained his post until within a few 

 years of his death, which took place at Hanover 

 on March 14, 1874. 



Madler's successor in the field of lunar as- 

 tronomy was Johann Friedrich Julius Schmidt 

 (1825-1884), who was born at Eutin in Liibeck 

 in 1825. At a very early age he gave indica- 

 tions of a taste for astronomy. Fortunately his 



