900 GEOLOGY OF ILLINOIS. 



fashioned into shapes fantastic, and gathered and piled up by the ro- 

 ving winds, extend in ridges and groups from Hock river to and among 

 the Winnebago swamps proper, in Bureau and Lee counties, and touch 

 the north-eastern portion of Henry. In the reports upon these latter 

 counties more will be said upon these shifting and roving hills and 

 chains of sand. 



Economical Geology. 



Coal. From the foregoing pages a good idea will be obtained of the 

 extent, quality, and accessibility of the coal deposits in this county. 

 The supply of this useful mineral is riot likely to soon become exhaust- 

 ed. As opened mines are worked out, new ones will be discovered. 

 But a small portion of the productive coal seams underlaying so large 

 a part of the county, diagonally from its north-west to its south-east 

 corner, has been properly or thoroughly prospected. Sources of wealth 

 hidden away from the eyes of man are yet to be developed, and the 

 coal of Henry county, for a long time to come, will furnish abundant 

 supplies for home consumption, and a still more abundaift supply for 

 neighboring markets. Such minerals as coal, iron, lime, and the like, 

 which minister so largely to the economies, utilities and conveniences 

 of life, are not only desirable in and of themselves, but become sources 

 of wealth and the highest material prosperity. Coal is second only to 

 iron in every quality that cau make it desirable. Especially in the 

 prairie counties of Illinois, where fuel is scarce, coal, in even ordinary 

 workable quantities, becomes of more than ordinary interest and value. 

 As a steam producer for the lower Eock river valley, when all its manu- 

 facturing and milling facilities shall be developed, these coal fields bor- 

 dering on the stream will obtain a new value. They will then be sought 

 after eagerly and developed to their full extent. 



Stone. The supply of building stone, as will have already been sur- 

 mised, is quite limited. The cap rock over the Cleveland coal seam will 

 furnish plenty of stone for cellars, wells, and ordinary mason work in 

 that part of the county. Stone of a better quality can there also be 

 quan ied from the Hamilton limestone in and near the river. The sup- 

 ply of limestone at Aldrich's coal mine is small, but of good quality. 

 The sandstone outcrops below Cleveland and on Mineral creek can also 

 be made to furnish abundance of a sandstone that will be useful for 

 many purposes. The other outcrops and stone quarries in the county 

 furnish only limited amounts of rather poor building stone. All the 

 railroad towns now draw their supplies of stone from the quarries at 

 Athens, Joliet, and other places in their vicinity, and will continue so 

 to obtain them. 



