226 GEOLOGY OF ILLINOIS. 



company manufacture the more ordinary crockery and pottery ware, but 

 they devote much attention to making drain tiles, coarse table ware, 

 terra cotta ware, garden ornaments, vases, and all similar articles. The 

 company has met a marked and deserved success, and well illustrates 

 what energy, skill and capital can make out of a bank of clay at one 

 time supposed to possess no very great value. The associate clays of 

 the Carbon Cliff Coal Measures are likely to possess a value far higher 

 than the four feet of coal worked in former years.* 



Rock Island County South of Rock River. 



That part of the county lying south of Eock river contains five full 

 townships and six pieces or fractions of regular townships, with an 

 area of perhaps two hundred and sixty square miles. It is bounded 

 north by Rock and the Mississippi rivers, west by the Mississippi, 

 south by Mercer county, and east by Henry county. It has an average 

 width of about nine miles from north to south, and a length from east 

 to west of about thirty-three miles. The Mississippi river at Rock 

 Island makes an abrupt bend to the west, and continues to flow in that 

 direction for some twenty miles, where it turns south again, and thus 

 almost washes the entire north and west sides of this part of the county. 



The surface is diversified, and is made up of alluvial bottom land, 

 hilly barrens, fertile and somewhat rolling upland prairies; the south- 

 ern townships, and large portions of Coal Valley, Bowling, Edgington 

 and Buifalo Prairie, are made up of the latter, under a higher degree of 

 cultivation. These prairies are the handsomest part of the county, and 

 gently roll away to the south and east, to the borders of Mercer and 

 Henry counties. On the south side of Rock river, from the Henry 

 county line to its confluence with the Mississippi below Rock Island 

 city, is a strip of alluvial or bottom land, from one to two miles in 

 width. Portions cf this are swampy and boggy ; others are sandy, 

 with ridges of fine gravel and sand blows ; and still others are rich 

 farming lands, which yield heavy crops of Indian corn, grass and grains. 

 Along the south side of this Rock river bottom the range of bluffs rise ab- 

 ruptly to an average of more than a hundred feet. At Andalusia the bluffs 

 approach the Mississippi river, and this latter stream washes their base 



*NOTK. Since the above report was written, this establishment has been changed from a common 

 pottery to the manufacture of drain tile ; and the material used is obtained from tlio silicious shale 

 that overlies the coal at this point. The shale is dug out where it lies immediately imdor the drift 

 clays, and has been thoroughly exposed to drift influences, by which its lithological characters have 

 been changed from alight gray shale to a silicious clay. The material used at Hampton, and formerly 

 used here for pottery, is the under clay of the coal seam formerly worked at this locality. Several 

 other beds of fire clay, apparently of good quality, occur in the lower Coal Measures iu this county, 

 and are mentioned in the local sections made at different points. 



