WHAT BEFORE THE MOLTEN GLOBE? 23 
the leaves in the springtime, and during the cold 
winter again discard them; in short, we know how 
the monarch of two thousand years obtained his 
growth by observing the growth of oaks of different 
ages. These observations give us a clear idea of the 
evolution of the tree. Similarly the astronomer ob¬ 
serves worlds in different stages of evolution, from 
the distant nebula to the airless, waterless, decayed 
moon. 
Many explanations have been attempted to account 
for the birth of the earth. About a century ago 
Pierre Simon Laplace, French mathematician and 
astronomer, put forth his explanation, which has since 
become famous as the “nebular hypothesis.” Be¬ 
fore stating his theory, let us see of what the solar 
system consists. 
In the center is the sun, a glowing globe nearly a 
million miles in diameter. The moon revolves about 
the earth at a distance equal to thirty times the earth’s 
diameter. Imagine the earth sunk into the center of 
the sun with its revolving moon around it. There 
would then be nearly as broad a belt of sun outside 
of the moon’s orbit as inside of it. Around this cen¬ 
tral sun revolve about four hundred planets, great 
and small, at various distances. The earth’s average 
distance from the sun is nearly ninety-three million 
miles. Revolving around the sun, inside of the 
earth’s orbit, are two of the eight major planets, Mer¬ 
cury and Yenus. Outside of our planet’s orbit, in the 
order of their distance from the sun are Mars, Jupi¬ 
ter, Saturn, Uranus, and Ueptune. The last revolves 
