474 THE PHYSICAL GEOGRAPHY OF THE SEA. 



land and sea are prevented from becoming seething hot, and by 

 ■which they are enabled to perform their wonderful offices with 

 certairty and regularit}^ 



891. Thus, perhaps, we discover a new office for the waves in 

 An office for waves in the physical cconomy of the ocean. Is it not to 

 ^^lesea. them that has been assigned the task of bringing 

 upj by their agitation of the surface, the layers of warm water 

 that are spread out below ? and are they not concerned also, as 

 they draw up the genial waters, in regulating the supply of heat 

 for the winds by night, as well as in cold or cloudy days, for the 

 purposes of evaporation ? Thus even the waves of the sea are 

 made, by this beautiful study, to present themselves as parts, im- 

 portant parts, in the terrestrial machinery. We now view them, 

 as it were, like balance-wheels in the complicated system of mech- 

 anism by which the climates of the earth are governed. If the 

 waves did not stir up the heated w^aters from below (§ 881), the 

 winds would evaporate slowly by night for the want of adequate 

 supplies of caloric ; the consequence would be less precipitation 

 and a more scanty supply of latent heat for liberntion in the cloud 

 reo-ion. As a consequence of this, the winds would have less mo- 

 tive power, and the whole climatic arrangements of our planet 

 would be different from what they are. 



892. It is curious to think that this subtile thing, called heat, 

 A reflection concern- which wc havc bccu Contemplating, now as latent 

 ingheat. jy^ ^]jq clouds abovc, uow as sensible in the waters 

 below, comes from the same source whence originally came the 

 heat which has been packed away in seams of coal and stored in 

 the bowels of the earth for ages and ages, to be called forth by 

 man at will for his own comfort, pleasure, and convenience ; that 

 this protean thing is the agent which controls sea and winds, and 

 they it ; that it is it which has lifted up the mountains, which 

 clothes the world with beauty, and keeps the stupendous flibric 

 of the universe in motion ; and that, after all, this mighty agent 

 is only that gentle thing that " warms in the sun !" 



893. Pursuing this subject, the philosophical mariner, as he sails 

 Probable relation be- aloug and Tccords obscrvations for these purposes, 



tween the actinometry _ -, ■■ •i,i ,t , i i 



oftheseaanditsdepth. may laucy — and perhaps rightly — that he has 

 traced to the actinometry of the sea one of the phj^sical conditions 

 which, when the depths of the ocean were laid, had its weight 

 with the Almighty Architect. 



