THE LUNAR WORLD. 95 



two feet high on the earth. Looked at from every point 

 of view, it seems hardly possible that there can be any 

 life on the moon resembling the life that we know of on 

 the earth. 



But though the want of atmosphere surrounding the 

 moon may deprive it of some features of interest, yet to 

 the user of a telescope on this earth the airless nature of 

 the moon is a distinct advantage. Suppose, for example, 

 that a Lunarian were to endeavour to study our earth with 

 the telescope, he would see little, comparatively speaking, 

 of the actual surface, for our atmosphere itself, so closely 

 enveloping the earth, would obstruct his vision, while the 

 clouds with which so large a part of our atmosphere is 

 often charged would form an impenetrable screen. It would 

 be only in a very imperfect fashion that the dweller on the 

 moon would be able to make out the features of the globe 

 to which the moon is a satellite. But the terrestrial 

 astronomer experiences no such difficulties. It is true that 

 our own atmosphere often interferes with us in a manner 

 with which every astronomer is only too painfully fami- 

 liar, but by suitable choice of opportunities these dis- 

 advantages may be largely obviated and beautiful pictures 

 of our satellite may be obtained. The want of atmosphere 

 on the moon enables us to see its features with exquisite 

 clearness and sharpness, and the shadows are cast with a 

 definition which we never find in terrestrial scenery. 



There is another circumstance which makes the moon 

 an attractive and easy subject for the telescopic inquirer. 

 Owing to the constant face of the moon, he always finds the 

 craters in nearly the same position, and as our satellite 

 courses through her monthly vicissitudes the observer 



