GEOLOGY OF ILLINOIS. 



brick. Neither did the under-clays of the thin coals above the Carlin- 

 ville limestone, at the several outcrops we examined, seem to be pure 

 enough to form a good fire-clay ; but as these under-clays frequently 

 change their local characters, it is by no means improbable that they 

 ' may be found somewhere in the county of good quality. 



Sand and Clay for Brick-mak'unj. These materials are abundant in 

 all parts of the county, and may usually be obtained from the beds im- 

 mediately beneath the soil on the uplands, and where there seems to be 

 a deficiency of sand in the subsoil-clays it may be easily supplied from 

 the beds of the streams, or from the sand-beds interstratified with the 

 drift-clays. 



Timber. Fine belts of timber skirt the banks of all the streams in 

 the county, furnishing an adequate supply for fencing the adjacent 

 prairie, and for fuel to those who prefer wood to coal. The principal 

 growth upon the uplands is two or three varieties Of oak and hickory 

 on the ridges adjacent to the streams, while on the more level lands 

 skirting the prairies there are fine groves which, in addition to these 

 varieties, contain elm, linden, wild cherry, honey locust, black walnut 

 and hackberry, and indicate a soil of excellent quality. On the creek 

 bottoms the cottonwood, sycamore, white and sugar maple, ash, redbud, 

 dogwood, sassafras, persimmon, paw-paw and white walnut are com- 

 mon. Since the introduction of the Osage orange for hedges, which 

 are now a common fence in this county, and the introduction of coal as 

 a common fuel, it may be safely estimated that the annual growth of 

 the timber is fully equal to the yearly consumption in this county. 



Soil and Agriculture. This county is situated in the heart of the 

 best corn-producing region in the State, and its prairie lands, which 

 constitute by far the largest part of its area, are unsurpassed among 

 the uplands in this State in fertility, and produce annually large crops 

 of "Indian corn, as well as the small grains and grass, without the aid 

 of fertilizers or artificial stimulants of any kind, and with a judicious 

 system of rotation of crops, I believe these lands might be thus culti- 

 vated for an indefinite period without any serious deterioration in their 

 productive qualities. 



The soil on the level prairie is of a black, peaty character, becoming 

 of a chocolate- brown color on the more rolling surfaces, and degenera- 

 ting into a light ash-gray colored soil on the oak ridges, which are the 

 poorest lauds in the county ; but these poorer soils upon the broken 

 lands that border the streams are excellent fruit lands, and also produce 

 good crops of wheat and clover, if properly cultivated. Underdraining 

 would no doubt greatly benefit the prairie soils, as the crops are much 

 injured in excessively wet seasons from the superabundance of moisture 



