62 ROUND THE YEAR 



of Yorkshire. They are commonly believed to be 

 true volcanic craters, but some of them are unlike 

 any terrestrial craters. There are deep circular 

 depressions, ringed about by steep walls, plains ringed 

 in the same way, craters with central elevations, and 

 circles of craters, as well as small craters of the usual 

 terrestrial form. 



The fact that the Moon turns always the same face 

 towards the earth implies that during every revolution 

 round the earth she rotates upon her own axis. If a 

 man walks round a tree, always keeping his face 

 towards it, he will face all quarters of the sky in turn, 

 that is, he will rotate. He will rotate in the same 

 direction as that in which he walks round the tree. 

 Thus the Moon rotates once in 27^ of our days, and 

 rotates against clock-hands. 



If we could stand on the surface of the Moon, we 

 should see great and small craters, some towering 

 into the sky, others low on the horizon. The distant 

 ones would be clear and sharp, for there are no 

 clouds or haze. We should see no streams or pools, 

 no long, narrow, branching valleys, and probably 

 no water-worn rocks or rounded pebbles. Some 

 observers, however, think that they can detect upon 

 the Moon traces of the former action of water and 

 even of moving ice. 



Let us suppose ourselves planted on that side of 

 the Moon which is turned towards the earth, and that 

 the sun shines upon us. The irregular surface of the 

 ground is lit by a fierce light, and all objects cast 

 deeper shadows than are ever seen on earth. Though 

 it is day, the sky is black and the stars shine with 



