WELLS OF GREENE COUNTY, ILLINOIS. 745 



INDIVIDUAL WELLS. 



At Roodhouse, in the north part of the count}', at an altitude about 6'50 

 feet above tide, wells obtain water at 15 to 25 feet in a gravel below clay. 

 A coal boring- is reported in the Geology of Illinois to have })enetrated 75 

 feet of drift, but one near the mill entered rock at 35 feet after penetrating 

 the following beds : 



Section of drift in a well at the Roodhouse mill. 



Feet. 



Loess 10 



Yellow till 15 



Blue till 10 



Total 35 



At Whitehall, 4 miles south of Roodhouse and at 75 feet lower eleva- 

 tion, the drift is shown by several wells to have a thickness of about 50 

 feet. In parts of the village strong wells are obtained at 20 feet, but in 

 other parts they are sunk to the rock. 



At Carrollton the public water supply is from a well 1,330 feet in 

 depth, which terminates in the St. Peter sandstone. It has a head 50 feet 

 below the surface, or 565 feet above tide. A peculiar series of beds were 

 penetrated before the rock was entered, there being a black muck about 32 

 feet in depth immediately below the loess, and under this beds of yellow 

 and red clay extending to the rock, no typical till being found. Rock was 

 entered at about 60 feet. 



At Greenfield the wells are 18 to 30 feet in depth and obtain then- 

 supply from gravel or from clay. The usual depth is about 20 feet. 



CALHOUN COUNTY. 



GENERAL STATEMENT. 



Calhoun County occupies the narrow strip of land between the Illinois 

 and Mississippi rivers just above their junction. It has an area of 260 square 

 miles, and Hardin is the county seat. The elevation is in places 350 feet 

 above the neighboring streams, and as the neck of land between the streams 

 is scarcely 6 miles in averag-e width, the topography is very rugged com- 

 pared with the general topography of Illinois. Glacial drift is found only 

 in a small portion of the county, and it is thought by Professor Salisbury, 



