EVAPORATION. 75 



retains the rain which then falls, and prevents the 

 soil below from drying so rapidly as it otherwise 

 would. The stores in the mountains are also exten- 

 sively and gradually distributed. A portion is taken 

 up by the evaporative power of the atmosphere, and 

 spread over the surrounding country ; while that which 

 is converted into water irrigates the surface, penetrates 

 into every fissure, and feeds the springs. 



But, though water has those singular properties that 

 fit it for seasonal distribution, so as to trace a maxi- 

 mum of beneficial effect upon all the productions of 

 nature ; and though, from the motions of the earth and 

 the varying action of heat upon the water, there be 

 a means of circulating that fluid over the whole range 

 of the ocean, the agency by which it is drawn up from 

 the earth's surface at one time, and poured down at 

 another, is probably more curious in itself, and cer- 

 tainly more influential in producing the changes of the 

 seasons. The subject is a very nice one, and we are 

 not, and probably never shall be, in possession of all 

 the elements that are required for the full explanation 

 of it ; but enough is known to warrant us in saying, 

 that the same two agencies which give the earth its 

 form and its distribution of light, raise this substance 

 from the sea and pour it again over the land; for 

 though we are not able to estimate the other causes 

 that may combine with heat in producing evaporation, 

 or with the gravitation or weight of water that brings 

 it down in rain, we know that other causes do operate, 

 and that their effect varies with their intensity, though 

 probably not, in either case, in the same ratio. We 

 know, too, that the atmosphere is the medium through 



