MAN’S THEATER OF ACTION 
by its close approach to the sun founded the solar system. 
It used to be supposed, when another hypothesis of its 
origin prevailed, that the earth cooled from the condition 
of a glowing hot ball until its crust formed, and that soon 
after that event it became fit for life. We are now more 
apt to believe, following Chamberlin and Moulton, who 
first advocated this view in the early years of the present 
century, that the earth is the product of gradual accretion 
of the train of finely divided solid meteoric matter which 
the supposed close approach of a star to our sun threw out 
as gases from the sun into space, but which soon cooled to 
solidification there before combining to form the earth. 
Some meteoric matter in individual masses of pounds or 
tons, and some thousands of minor planets, which are 
mineral masses of some miles in diameter, still are met 
with in the solar system. But nearly the whole of the 
matter which it is supposed escaped from the sun owing 
to the near approach of another star, 1s now collected to 
form the eight great planets and their moons. 
In the progress of accretion it is not to be supposed that 
the earth was at first of regular shape or complete solidity. 
But as more and more matter accumulated, its growing 
pressure gradually squeezed out the lighter parts, includ- 
ing the present earth’s crust and the water and air. The 
water settled into depressed regions and, adding to their 
weight, tended the more to depress them. Also, then as 
now, the action of the atmosphere 1n producing decompo- 
sition and disintegration, and of the rains and streams in 
wearing off the elevated parts, tended to remove the 
heavier portions of the rocks, which on the whole are more 
soluble. This detritus, finding its way to the incipient 
oceans, tended the more to emphasize the oceanic depres- 
sions and to tilt still higher the land elevations. 
Under the enormous weight of the outer part of the 
earth, its inner portion flows slowly as if it were a viscous 
fluid. Experiments have shown that the crust to a depth 
of about sixty miles behaves like a floating island, tilting 
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