256 TRANS. ST. LOUIS ACAD. SCIENCE. 



intense during summer there was an immense amount of watery 

 vapor in the atmosphere ready to be condensed in dekiging show- 

 ers upon the slightest change in the temperature. 



At the present time all our prairie land is in cultivation, or used 

 as pasture ; the ponds and small lakes have become so filled up 

 that they contain less than half the former amount of water ; 

 the stock now consumes the reeds and marsh-grass, exposing the 

 water to the direct rays of the sun, thereby promoting evapora- 

 tion, so that by mid-summer even the muck in their basins has 

 dried to a hard crust, and a change in the temperature during 

 the heated term brings, as a rule, a cool, dry atmosphere instead 

 of rain, as in former years. The large amount of water consumed 

 by our domestic animals, which have increased with the increase 

 of population, must not be overlooked. In this State, at the 

 present time, we have at least three million horses, cattle, and 

 mules, and five million hogs and sheep, and they will consimie 

 not less than seventy million gallons of water every twenty-four 

 hours — qviite a lake of itself. 



As I before remarked, it is the aqueous agent that is hard at 

 work night and day, summer and winter, overcoming every ob- 

 stacle placed by nature or man to impede its progress. The work 

 marked out for it to do is no less than the complete drainage of 

 the ponds and lakes of our prairies ; and so surely as the world 

 stands, so surely will the task be accomplished in a thoi'ough and 

 workmanlike manner. Every little streamlet has its miniatui'c 

 Niagara Falls ; but, unlike their giant relation, they are making 

 visible progress every year, and are consequently (strange as the 

 language may seem) more instructive. The "hard-pan," which 

 only yields after repeated blows from the sturdy laborer's pick, 

 and grinds oft' its steel at the rate of two inches per day, crumbles 

 and gives way under the combined agency of frost and water : 

 the largest trees in the forest yield to the conquering element. 



To convey an idea of what I mean, let me give you an account 

 of the progress made during the last quarter of a century by one of 

 these small cataracts, as witnessed by the writer. Spring Branch 

 empties into the Middle Fork of Shoal Creek, near the town of 

 Hillsboro, Montgomery Co., Ills. ; it has three large tributaries ; 

 the main branch is about four miles long, and its source is a large 

 lake and several small ponds in the same neighborhood. Tlie 



