48 NATURAL HISTORY. 



it is said there are parts above a mile deep, but these 

 are few, and the most general profundities are from 60 

 to 150 fathoms. The gulphs bordering on the coasts 

 are much shallower, and the straits have generally the 

 least depths. 



In general, the depths in open seas increase or di- 

 minish pretty regularly, being for the most part deeper 

 the farther from land. But there are places in the 

 middle of the sea, as at the Abrolkos in the Atlantic, 

 where large shelves appear ; and in other places, there 

 are vast sand banks, to which the East Indiamen are 

 no strangers. 



Along coasts, the depths are also very irregular. 

 Yet it may be laid down as a certain rule, that the 

 depth is always proportioned to the height of the coast : 

 the same remark is equally applicable to rivers. 



The highest mountains in Asia, are Mount Taurus, 

 Mount Imaus, Caucasus, and the mountains of Japan, 

 all of which are higher than any in Europe : the high- 

 est mountains in Africa, i, e. the great Atlas, and the 

 mountains of the moon, are at least as high as those 

 in Asia, and the highest of all are in South America, 

 particularly those of Peru, which are more than 3000 

 fathoms higher than the level of the sea. In general, 

 the mountains between the tropics are loftier than those 

 of the temperate zones, and these more than those of 

 frigid zones, so that the nearer we approach the equator, 

 the greater are the inequalities of the earth : these in- 

 equalities, although very inconsiderable with respect 

 to us, are nothing when considered with respect to the 

 terrestrial globe. Three thousand fathoms difference to 

 3000 leagues diameter, is one fathom to a league, or 

 one foot to 2300 feet, which on a g'obe of 2 feet and 

 a half diameter, does not make the 6th part of a line. 



