578 THE ILLINOIS GLACIAL LOBE. 



without entering rock. Water is obtained in gravel near the bottom, the 

 greater part of the well section being till. 



In the vicinity of Cary wells are 60 to 100 feet in depth. They 

 usually penetrate about 50 feet of dry gravel, beneath which is till, having 

 water-bearing beds associated with it. 



At Algonquin, in the southeast corner of the county, an artesian well 

 was sunk to a depth of 2,527 feet by the Illinois Condensing Company. 

 Rock is struck at about 100 feet, and the well probably terminates in Pots- 

 dam sandstone. At last reports the use of the well had been discontinued 

 because of the corrosion of the pipes by the water. The public water sup- 

 ply for this village is from springs. Many wells on the low ground obtain 

 water at about 12 feet. A few have been bored to depths of 60 or 80 feet. 

 They enter till after penetrating 12 to 20 feet of gravel. Occasional flow- 

 ing wells are obtained in this vicinity. One in the valley of Crystal Lake 

 outlet, about a half mile above Algonquin, has a depth of 60 feet. One at 

 a blacksmith shop in the north part of Algonquin is 62 feet in depth, and 

 has a head 14 feet above the surface. The bordering uplands rise to a height 

 of about 100 feet above the level of the wells, and thus furnish an absorb- 

 ing area of sufficient height to give a strong hydrostatic pressure. 



At South Riley, in the southwest part of the county, rock is usually 

 entered below blue till at a depth of about 60 feet, or at an elevation not 

 far from 800 feet above tide. Rock is also struck in several wells on the 

 plain northwest from Marengo, in the southwest part of T. 45, R. 5 E., and 

 northwest part of T. 44, R. 5 E., at a depth of about 60 feet. The general 

 elevation of the region is about 850 feet above tide. A short distance east 

 from these wells, however, a well on the farm of Mr. Alsing, sec. 35, T. 45, 

 R. 5 E., reached a depth of 100 feet without entering rock. 



The following sections of farm wells are of interest because of their 

 depth. They are located on or among the moraines of the Wisconsin drift 

 sheet and none of them reach the rock: 



Deep drift borings in southeastern McHenry County. 



Feet. 



Moses DiraoD, 2 miles south of Marengo 125 



R. Cooney, sec. 14, T. 45, R. 6 E 94 



Harmony post-office 112 



Ira Curtiss, near center of T. 43, R. 6 E 180 



AVell 80 rods east of preceding 86 



W. Wliittemore, T.43, R.7E 100 



Mr. Cummings, near Huntley 108 



George Bunker, T. 44, R. 7 E 84 



