EAIMS AND RIVERS. 129 



oOl. Tlie rivers of India, and the measure of the effective eva^wra- 

 fion from that ocean. — The rivers of India are fed by the monsoons, 

 which have to do their Avork of distributing their moisture in 

 about three months. Thus we obtain 0.0G5 inch as the average 

 daily rate of eff^cctive (§ 282) evaporation from the warm waters 

 of this ocean. If it were all rained down upon India, it would 

 give it a drainage which would require rivers having sixteen 

 times the capacity of the Mississippi to discharge. Neverthe- 

 iess, the evaporation from the North Indian Ocean required for 

 such a flood is only one-sixteenth of an inch daily throughout 

 the year.* Availing myself of the best lights — dim at best — as 

 to the total amount of evaporation that annually takes place in 

 the trade-wind region generally at sea, I estimate that it does not 

 exceed four feet. 



302. Physical adjustments. — We see the light breaking in upon 

 us, for we now begin to perceive why it is that the proportions 

 between tlie land and water were made as we find them in 

 nature. If there had been more water and less land, we should 

 have had more rain, and vice versa ; and then climates would 

 have been different from what they are now, and the inhabitants, 

 neither animal nor vegetable, would not have been as they are. 

 And as they are, that wise Being who, in his kind providence, 

 •so watches over and regards the things of this world that he 

 takes note of the sparrow's fall, and numbers the very hairs of 

 our head, doubtless designed them to be. The mind is delighted, 

 and the imagination charmed, by contemplating the physical 

 arrangements of the earth from such points of view as this is 

 which we now have before us ; from it the sea, and the air, and 

 the land, appear each as a part of that grand machinery upon 

 which the well-being of all the inhabitants of earth, sea, and 



* In his annual report of the Society {Transactions of the Bombay Gengra- 

 plu'cal Society from May, 1849, to August, 1850, vol. ix.), the late Dr. Buist, 

 the secretary, stated, on the authority of Mr. Laidly, the evaporation at Cal- 

 cutta to be " about fifteen feet annually ; that between the Cape and Calcutta 

 it averages, in October and November, nearly three-fourths of an inch daily ; 

 between 10*^ and 20^^ in the Bay of Bengal, it w\as found to exceed an inch 

 •daily. Supposing this to be double the average throughout the year, we 

 should," continues the doctor, " have eighteen feet of evaporation annually." 

 All the heat received by the intertropical seas from the sun annually would 

 not be sufficient to convert into vapour a layer of water from them sixteen 

 feet deep. It is these observations as to the rate of evaporation on shore that 

 have led (§ 280) to such extravagant estimates as to the rate at sea. 



K 



