236 GEOLOGY OF ILLINOIS. 



the expense of hauling good stone five miles, than to use at less expense, a ma- 

 terial which will insure the ultimate destruction of the buildings by weathering 

 at no very distant day. 



Water. Artesian wells can probably be obtained anywhere in the county, 

 at a depth nowhere exceeding twelve hundred feet ; and it is probable that a 

 permanent supply could be had at nine hundred feet in the western part of the 

 county. The water from the St. Peters sandstone has, in some cases, been 

 found quite saline ; but in such cases a purer water can generally be reached 

 by boring into the underlying Calciferous sandstone, and tubing out the upper 

 flow. No artesian wells have yet been obtained in this county, the only deep 

 boring, the " oil well," south of Kankakee City, having stopped at the top of 

 the Trenton limestone. The Drift beds which supply the numerous flowing 

 wells of the south part of Iroquois county, apparently do not exist north of the 

 east and west portion of the Iroquois river valley. 



Iroquois county is bounded on the north by Kankakee county ; on the west, 

 by Livingston and Ford ; on the south, by Ford and Vermilion counties ; and 

 on the east by Indiana. It contains eleven hundred and fifty-six square 

 miles, being thirty-four miles square. Of this area, far the larger part is 

 gently rolling prairie. The northeastern quarter is separated from the rest of 

 the county by the Iroquois river, which, entering the county from Indiana, a 

 little north of the center of its east line, flows in a general west course to near 

 the middle of the county, and thence nearly due north into Kankakee county. 

 This stream is quite sluggish, and navigable for flat-boats from the northern 

 county-line up to Middleport ; above this point, it is smaller and more broken. 

 Its principal branches are Sugar creek, from the southeastern part of the 

 county, and Spring creek, from the southwestern. All these streams have 

 considerable bottoms, but those of the main Iroquois are especially interesting, 

 on account of their connection with the subject of the old Lake Kankakee. 

 All along this valley, and for considerable distances from the present river 

 bottoms, we find the extensive accumulations of sand which mark the bottom 

 and shores of the old river valley. These beds have not been traced along the 

 upper part of the river, so as to ascertain whether or not they are continuous 

 with those of the upper Kankakee, as has been suspected ; but the lower 

 portion of the valley was certainly filled by a broad arm of the expanded chan- 

 nel through which the waters of Lake Kankakee passed to the narrower outlet 

 below. In my report upon Kankakee county, I have expressed the opinion 

 that Lake Erie may possibly have, at one time, poured out its waters in this 



NOTE. The map referred to on page 228 has not been published for the lack of means to 

 defray the expense of engraving. The most essential parts of it will, however, be transferred 

 on to the State map, now in process of construction, to accompany the final volume of these 

 reports. A. H. W. 



