COSMIC PHILOSOPHY 



Here there is an apparent discrepancy, which 

 will disappear, however, when we inquire further 

 into the past career of the moon as indicated by 

 the present condition of its surface. To a great 

 extent the lunar surface is made up of huge 

 masses of igneous rock, through which at short 

 intervals yawn enormous volcanic craters, whose 

 fires seem to be totally extinguished. The giant 

 forces required to bring about such a state of 

 things are now quiescent. And this implies that 

 the moon is a dead planet. It implies that the 

 thermal energies which were once instrumental 

 in raising those huge cones, Tycho, Copernicus, 

 and the rest, — quaintly named after our terres- 

 trial heroes of science, — and which once drove 

 up fiery streams of molten lava through their 

 ample mouths, are now clean gone, radiated off 

 into space. This cessation of volcanic activity 

 indicates that the planet has reached its limit of 

 consolidation, and is no longer generating heat 

 from within. 1 Now the degree of cold implied 



1 "Nevertheless, there are processes at work out yonder 

 which must be as active, one cannot but believe, as any of 

 those which affect our earth. In each lunation, the moon's 

 surface undergoes changes of temperature which should suffice 

 to disintegrate large portions of her surface, and with time to 

 crumble her loftiest mountains into shapeless heaps. In the 

 long lunar night of fourteen days, a cold far exceeding the 

 intensest ever produced in terrestrial experiments must exist 

 over the whole of the unilluminated hemisphere ; and under the 

 influence of this cold all the substances composing the moon's 

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