36 VESTIGES OF THE 



earth, at a certain point of time after it was thrown off 

 from the sun, was no less than 482,000 miles in diameter, 

 being sixty times what it has since shrunk to. At that 

 time, the mass must have taken rather more than 

 twenty-nine and a half days to rotate (being the revolu- 

 tionary period of the moon), instead of as now, rather 

 less than twenty-four hours. 



The time intervening betwen the formation of the 

 moon and the earth's diminution to its present size, was 

 probably one of those vast sums in Avhich astronomy 

 deals so largely, but which the mind altogether fails to 

 grasp. 



The observations made upon the surface of the moon 

 by telescopes tend strongly to support the hypothesis as 

 to all the bodies of space being composed of similar 

 matters, subject to certain variations. It does not 

 appear that our satellite is provided with that gaseous 

 envelope which, on earth, performs so many important 

 functions. Neither is there any appearance of water 

 upon the surface ; yet that surface is, like that of our 

 globe, marked by inequalities and the appearance of 

 volcanic operations. These inequalities and volcanic 

 operations are upon a scale far greater than any 

 which now exist upon the earth's surface. Although, 

 from the greater force of gravitation upon its exterior, 

 the mountains, other circumstances being equal, might 

 have been expected to be much smaller than ours, they 

 are, in many instances, equal in height to nearly the 

 highest of our Andes. They are generally of extreme 

 steepness, and sharp of outline, a peculiarity which 

 might be looked for in a planet deficient in water and 

 atmosphere, seeing that these are the agents which wear 

 down rufi^o-edness on the surface of our earth. The 

 volcanic operations are on a stupendous scale. They are 



