4S NATURAL HISTORY. 



In examining and describing the surface of the earth 

 the first object which solicits our attention is that body 

 of water with which the greater part of the globe is 

 covered. The waters occupy the lower grounds, and 

 notwithstanding their uniform tendency to rest, they 

 are kept in continual agitation by an agent, that com- 

 municates to them a regular periodic motion, which 

 produces a vibration, even to the most profound depths 

 in the whole mass. 



When we explore the bottom of the sea, we discover 

 hills and valleys, plains and hollows, and rocks and 

 earths of every sort. We discover too that islands 

 are only the summits of vast mountains ; we likewise 

 find other mountains whose tops almost reach the sur- 

 face of the w r ater ; and rapid currents which counter- 

 act the general movement ; and of which the motion 

 is sometimes in the same direction, and at other times 

 retrograde. On the one hand, we meet with tempestu- 

 ous regions, where the heavens and the ocean seem 

 equally confounded in the general shock ; violent in- 

 testine emotions, tumultuous swellings, water-spouts, 

 and strange convulsions produced by volcanoes, and 

 dreadful whirl-pools. On the other hand, we discover 

 vast regions always calm, but equally dangerous to 

 the mariner. In short, when we direct our eyes to- 

 wards the polar regions, we perceive huge masses of 

 ice, which having detached themselves from them, ad- 

 vance, like floating mountains, till they dissolve in the 

 temperate climates. 



Besides tl>ese grand objects, the ocean exhibits an 

 infinite variety of animated beings ; all of which find 

 abundance of food in this fluid element. 



But when we take a view of the land, what differ- 

 ences tajce place in different climates ! what a variety 



