786 THE ILLINOIS GLACIAL LOBE. 



also reported that a log- was found near the bottom. This well indicates 

 that the present stream is flowing at a level considerably higher than the 

 preglacial rock floor. 



At Anna the wells are 20 to 60 feet in depth, the majority being about 

 40 feet, and obtain water in limestone. The city authorities are considering 

 the advisability of constructing waterworks. The best wells are estimated 

 to have a capacity of about 100,000 gallons a day. The source for the 

 public water supply might therefore be found in these wells. 



At Vienna wells are obtained at 25 to 60 feet in limestone, the usual 

 depth being about 50 feet. An average well is estimated to yield about 12 

 barrels of water a day. 



The village of Thebes stands in a portion of the Mississippi Valley 

 which is postglacial, and wells obtain water at the top of the rock at a 

 depth of only 20 feet. The residents depend largeh r upon cistern water. 



At Cairo the waterworks are supplied from the Ohio River. Excavated 

 wells are not allowed within the city limits. Driven wells have been sunk 

 to depths of 70 to 200 feet. No solid rock is reached at the latter depth. 

 The citv engineer reports that good water is obtained at about 70 feet. 

 The following section of a boring for a bridge, by the Illinois Central Rail- 

 road Company, was furnished by the city engineer. The surface elevation 

 is 45 feet above low water at the mouth of the Ohio. The boring therefore 

 reaches a level 80 feet below the low- water mark: 



Section of boring for bridge of Illinois Central Railroad at Cairo, Illinois. 



Feet. 



Mud and sand •- 15 



Fiuc sand 40 



Coarse sand and gravel 30 



Coarse saud, gravel, and fragments of sand rock 15 



Fine sand and gravel - 10 



Fine white sand - 15 



Total depth - 125 



This boring should be compared with borings made by the United 

 States Army Engineers at points between Cairo and Vicksburg. 1 



At Metropolis the public water supply is pumped from the Ohio 

 River, but there are numerous wells about 40 feet in depth. These wells 



1 See reports of the Chief of Engineers, United States Army, for 1877, 1878, and 1879; also 

 Report of Mississippi River Commission, 1881, pp. 171-239. 



