262 GEOLOGY OF ILLINOIS. 



strippings, I observed four or five thin, irregular bands of a very compact, 

 highly calcareous sandstone, of very irregular fracture, which are said to have 

 furnished some stone for the piers of the T. W. & W. 11. R bridge. They ap- 

 pear solid in the outcrop, but the quantity is small, and the irregular fracture 

 would interfere with ready working. 



On Makemson's branch, as before mentioned, there are some heavy beds of 

 ferruginous sandstone, which appear better fitted for resisting the action of the 

 weather than any other stone in the county. They are underlaid by softer 

 bads, which have been washed away by the stream, so as to leave the upper 

 beds projecting many feet in some cases. They may be found somewhat soft 

 in quarrying, but will harden upon exposure, and make a permanent stone, un- 

 less they are quarried so late in the season as to freeze before the quarry water 

 is dried out of them. 



Along Salt Fork, below Gonkeytown, a layer near the bottom of No. 2 of the 

 county section, has yielded small quantities of very solid, calcareous sandstone, 

 apparently permanent. Above this point, stone 1ms been quarried at several 

 places. Davis's quarry, in section 81, township 19 north, range 13 west, is the 

 only one now open. The stone is soft in the qu irry, but is said to become very 

 hard and durable upon exposure, in consequence of the cementing quality of a 

 small quantity of oxyd of iron. 



The limestone near Fairmount, so far as now exposed, is too shaky to be 

 suitable for building. The upper layers of this bed, in Edgar county, have 

 furnished some good stone for rough uses, and possibly corresponding beds may 

 yet be developed here, especially at the southern extremity of the outcrop. 



The drifted masses of Silurian limestone in the north part of the county, are 

 still sufficiently numerous to be mentioned as a source of building stone for 

 that region. 



The clay subsoil throughout the timber, w4R furnish abundant material for 

 brick making, and small quantities are manufactured at several points. The 

 yard of Perry Fairchild, at Danville, is especially worthy of mention. It fur- 

 nishes from three to four millions of brick per annum. 



Fire Cloy. As already stated, this article exists in very la-'ge quantities 

 below both of the principal coal beds, especially the lower one. The greatest 

 development noticed is on J. Ogden's land, about three miles northeast of 

 Georgetown. No use has been made of it, thus far; but it is well deserving 

 of attention. 



Iron Ore. Along the banks of the Little Vermilion, for some miles below 

 Georgetown, large quantities of nodular carbonate of iron are scattered and 

 piled. The quality of the ore is not constant; but I judge that the larger 

 part of it would yield from twenty-five to thirty-five per cent, of metal. The 

 layers are so scattered in the shale, ajid so irregular in thickness, that no proper 



