704 THE ILLINOIS GLACIAL LOBE. 



importance within its limits. Much of the county has a veiy level surface 

 which requires artificial drainage. 



The few borings of which records were obtained indicate that the 

 county is covered with a very thick sheet of drift, averaging probably more 

 than 200 feet. The greater part of the drift appears to be blue till. Shal- 

 low wells of moderate strength are often obtained at depths of 25 to 40 

 feet, but tubular wells are usually sunk to depths of 100 feet or more and 

 obtain stronger supplies than at shallow depths. 



INDIVIDUAL WELLS. 



At Monticello the public water supply, as noted on page 220, is from 

 two wells 212 and 316 feet in depth, neither of which enters rock. 



At Bement the public water supply is obtained from two wells, one 138 

 feet, in gravel below till, the other 225 feet, in rock the lower 3 feet. The 

 shallower one obtains the larger supply of water. The Wabash Railway 

 has a strong well at this village 152 feet in depth, from gravel below till. 

 A well at the mill, 141 feet in depth, is also in gravel below till. Joseph 

 Rodman sunk a well to a depth of 384 feet, which entered rock at 205 

 feet. A well at the Bement cemetery, 2 miles north of the villag-e, at an 

 altitude about 45 feet higher, reached a depth of 221 feet without entering 

 rock, and a well one-half mile east of the cemetery, 222 feet in depth, did 

 not reach rock. 



At Cerro Gordo several wells have been sunk to a depth of about 150 

 feet without reaching rock. They are mainly through blue till, and in 

 some cases are rather weak. 



A well near Mansfield, on the farm of Mrs. R. Carson, as noted on 

 page 234, reached a depth of 200 feet without entering rock, mainly 

 through sand. 



DEWITT COUNTY. 

 GENERAL STATEMENT. 



Dewitt County is situated in the central part of the State, west of the 

 northern portion of Piatt County, and south of McLean County. It has an 

 area of 405 square miles, and Clinton is the county seat. Salt Creek, a 

 tributary of the Sangamon River, leads westward through the central por- 

 tion of the county, and is the main stream within its limits. The western 



