CHAPTER V 



THE ATMOSPHEEE AND ITS SEEVIOE TO MAN 



The Origin of the Atmosphere. When the earth cooled 

 from its original intensely hot condition, the substances 



BLUE HILL OBSERVATORY, MILTON, MASSACHUSETTS 



One of the first places in America where conditions of the upper 

 atmosphere were studied. 



which did not chemically combine to form liquids and solids, 

 or which required a very low temperature for their consoli- 

 dation, were left still in the gaseous state around the solid 



96 



