744 ' THE UNIVERSE. 



of this incandescent focus, which burns us at a distance of 

 91,328,600 miles, astronomers are so daring that they 

 have ventured to calculate the quantity of water necessary 

 if not to extinguish it entirely, to put out at any rate the 

 surface conflaOTation. 



CHAPTER II. 



THE EARTH. 



We have previously spoken at length of the earth in 

 reference to geology; here we only have to speak of its 

 position as a planetary body forming part of the solar 

 system. 



The earth represents a sphere a little flattened towards 

 the poles. It is subject to two movements, one which 

 takes place round the sun in an orbit of which it traverses 

 the circuit in a year, the other is performed in about twenty- 

 four hours round the axis which passes through its poles. 

 It is the latter movement which occasioned the belief that 

 the sun and the heavens turn round the earth in a direction 

 from east to west, whilst on the contrary it is the terrestrial 

 globe that turns from west to east. Copernicus was the 

 hrst to demonstrate this great astronomical fact, and 

 Galileo, with all the influence of his genius, confirmed it. 



The terrestrial surface is estimated at 190,000,000 square 

 miles, and the learned have calculated that to cover it 

 completely would require a thousand kingdoms the size 

 of France. 



