WELLS OF HENKY COUNTY, ILLINOIS. 623 



lected b) T the writer. A well driller at Aledo states that a peaty soil is 

 occasionally struck in the western part of this county at a level lower than 

 the base of the loess, it being in some instances 45 feet below the surface. 

 This is probably the Yarmouth soil of pre-Ulinoian age. A soil is also 

 found at the base of the loess, 15 or 20 feet below the surface, which is 

 evidently the Sangamon soil. 



The thickest section of drift reported within the county is in a well 

 one-half mile northeast of Joy, where a depth of 70 feet was reached with- 

 out entering rock. A ravine leading into the Mississippi Valley just north 

 of the county line exposes 130 feet of drift, as noted in the discussion of 

 Rock Island County. 



HENRY COUNTY. 

 GENERAL STATEMENT. 



Henry County is situated east of Rock Island and Mercer counties, and 

 has an area of 830 square miles, with Cambridge as the county seat. Rock 

 River forms a portion of its border on the northwest ; Green River traverses 

 its northern portion in a westward course, and Edwards River its southern 

 portion. The north part of the county from the vicinity of the Chicago, 

 Rock Island and Pacific Railroad northward is a low sandy area, imper- 

 fectly drained by Green River. The remainder of the county is an upland, 

 standing 100 to 200 feet higher than the sandy lowland, a considerable por- 

 tion being more than 800 feet above tide. A bluff-like rise in part an 

 escarpment of sandstone which appears just south of the line of the Chi- 

 cago, Rock Island and Pacific Railway is the most conspicuous topographic 

 feature of the county, though it seldom exceeds 100 feet in height, and 

 is coated with drift to an average depth of fully 50 feet. 



The drift is generally of moderate depth, though a few wells in the 

 west part of the county have penetrated 150 feet or more. It is probable 

 that the drift is heavy in much of the low area in the north part of the 

 county since it is heavy in the adjacent part of Bureau County; but wells 

 have not been sunk in that district to a sufficient depth to test this question. 



INDIVIDUAL WELLS. 



The public water supply at the city of Geneseo, in the northwest part 

 of the county, is obtained from an artesian well 2,250 feet in depth, which 

 terminates in the Potsdam sandstone. The well is 6 inches in diameter and 



