262 Kansas Academy of Science. 



and produced the markings that we can see even with the 

 unaided eye, as well as all the others that are revealed by the 

 aid of the telescope. 



The larger fragments, plunging in earlier in the stage of 

 cooling, produced the large, uneven lower areas called sea bot- 

 toms, and later the smaller ones entering the less fluid mass 

 produced the so-called craters which are seen to overlap each 

 other just as they would do if produced in the manner de- 

 scribed. 



If we take plaster of paris and mix it so that it will not 

 set too quickly, and then throw in various-sized shot or mar- 

 bles just before and during the time of setting, we can make 

 a very good map of any portion of the moon's surface. 



Some may ask why the earth does not present the same 

 features as the moon, for certainly it was subjected to a like 

 bombardment of these fragments while it was cooling, and 

 should show an even rougher surface than the moon. 



In answer to this it may be said that the moon, having no 

 air and being devoid of water, has retained all of its original 

 features just as they were when finally cooled. . The earth, 

 on the other hand, has been subjected to the combined action 

 of water and climatic changes, so that for thousands of feet 

 below the present surface, all that we know of it, in fact, has 

 been worked over and over again, and so leveled down till 

 all of the original features have been obliterated. 



