THE SIDEREAL UNIVERSE. • 747 



The moon is in every part roughened with eminences of 

 different shapes, but they only very rarely group them- 

 selves into mountain chains comparable to those of our 

 globe. The Alps, Caucasus, and the Apennines repre- 

 sent the principal ones. Certain isolated summits have 



3iS. Appearance of the lloon wheu Full. 



received the names of celebrated men, but those of past 

 times have been chosen in order not to excite any jeal- 

 ousy; we travel from the Mountain of Aristotle to that of 

 Hipparchus, from that of Ptolemy to that of Copernicus. 

 The astronomers have very properly not forgotten their 

 claims. 



The highest lunar mountains attain an altitude which 

 surpasses most terrestrial elevations, a fact which may 

 well astonish us. Generally they do not rise beyond 

 22,750 feet. But in proportion to the size of the planet, 

 we may say that the mountains in the moon are much 



