224 GEOLOGY OF ILLINOIS. 



Economical Geology. 



The horny, tough, splintery layers of the Niagara limestone burn into 

 an excellent quick lime. It is white, strong, and pure. At Cordova and 

 Port Byron fires almost perpetually glow in extensive lime kilns, and 

 the lime made at these localities has a wide reputation and commands 

 a ready sale, and an extensive business in this line is done here. The 

 Hamilton limestone of Eock Island is a very pure carbonate of lime, 

 and is manufactured into a good article of quck lime. It is extensively 

 used in the government works and buildings, now in process of erection 

 on the Island, and although coarse, it is strong and makes a firm cement 

 for heavy masonry. 



Lime enters extensively into all the arts, uses, and utilities of life. 

 Like iron, coal, clay, sand, and many other familiar materials of daily 

 use, we seldom stop to consider its many uses in the economies and con- 

 veniences of life, and the localities oifering facilities where it can be" 

 manufactured cheaply and of superior quality, have elements of material 

 wealth worthy the attention of capitalists and political economists. 

 Such localities exist at Cordova, Port Byron, Albany, Hock Island, and 

 other places along the Mississippi in this part of the county. Trans- 

 portation by rail and water is easy, coal and wood are abundant and 

 accessible for fuel, the Niagara cliffs and Devonian beds furnish 

 abundance of the raw limestones, and no better place can be found for 

 making the manufacture of lime a good paying business. 



The coal seams north of Rock river, as before stated, are limited. At 

 Carbon Cliff the seam was four or five feet thick, and for a time was 

 worked with profit. But the deposit there seemed to be but an outlier 

 and has now ceased to be mined to any extent. Traces of coal were 

 also discovered in the bluffs opposite Cleveland, in the township of 

 Hampton, and also further towards the east line of the county in the 

 township of Zurna. At Coal Town, midway between Carbon Cliff" and 

 Camden, some old coal banks at the base, or near the base of the bluffs, 

 in former years, furnished considerable coal, of a quality similar to that 

 found at Carbon Cliff. It will thus be seen that coal and traces of coal, 

 together with Coal Measure sandstones and shales, are more numerous 

 north of Rock river than has been generally supposed. The northern 

 edge of the great Illinois coal field rests unconforuiably upon the Ham- 

 ilton and Niagara limestones from near Port Byron, on the Mississippi 

 river, to where the bluff' line abruptly trends north on striking the bot- 

 tom of the Maredosia slough, and indeed north-east from thence to the 

 sandstone quarries of Whiteside county on Cat-tail slough and north of 

 Morrison. The triangular piece of elevated land east of Eock Island 



