104 PHYSICAL GEOGRAPnY OF THE SEA, AND ITS METEOROLOGY. 



after day, and year after year, discharging immense volumes of 

 water into the ocean. *' All the rivers run into the sea, yet the 

 sea is not full." — Eccl. i. 7. Where do the waters so discharged 

 go, and where do they come from? They come from their 

 sources, is the ready answer. But whence are their sources 

 supplied ? for, unless what the fountain sends forth be re- 

 turned to it again, it will fail and be dry. We see simply, in 

 the waters that are discharged by these rivers, the amount by 

 which the precipitation exceeds the evaporation throughout the 

 whole extent of valley drained by them ; and by precipitation I 

 mean the total amount of water that falls from, or is deposited 

 by the atmosphere, whether as dew, rain, hail, or snow. The 

 springs of these rivers (§ 191) are supplied from the rains of 

 heaven, and these rains arc formed of vapours which are taken 

 up from the sea, that "it be not full," and carried up to the 

 mountains through the air. "Note the place whence the rivers 

 come, thither they return again." Behold now the waters of the 

 Amazon, of the Mississippi, the St. Lawrence, and all the great 

 rivers of America, Europe, and Asia, lifted up by the atmosphere, 

 and flowing in invisible streams back through the air to their 

 sources among the hills (§ 191), and that through channels so 

 regular, certain, and well-defined, that the quantity thus con- 

 veyed one year with the other is nearly the same : for that is the 

 quantity which we see running down to the ocean through these 

 rivers ; and the quantity discharged annually by each river is, 

 as far as we can judge, nearly a constant. 



2G8. Powerful machinery. — We now begin to conceive what a 

 powerful machine the atmosphere must be ; and, though it is 

 apparently so capricious and wayward in its movements, here is 

 evidence of order and arrangement which we must admit, and 

 proof which we cannot deny, that it performs this mighty office 

 with regularity and certainty, and is therefore as obedient a law 

 as is the steam-engine to the will of its builder. It, too, is an 

 engine. The South Seas themselves, in all their vast inter- 

 tropical extent, are the boiler for it, and the northern hemisphere 

 is its condenser (§ 24). The mechanical power exerted by the 

 air and the sun in lifting water from the earth, in transporting it 

 from one place to another, and in letting it down again, is 

 inconceivably great. The utilitarian who compares the waters 

 power that the Falls of Niagara would afford if applied to 

 machinery, is astonished at the number of figures which are 



