106 GEOLOGY OF ILLINOIS. 



two dollars per ton. It was said to yield about thirty gallons of oil per ton, 

 but the subsequent discovery of oil in Pennsylvania and Ohio, put a stop to its 

 manufacture from cannel coal in this region. 



Fire Clay. A good bed of fire clay, from three to five feet in thickness, oc- 

 curs below the cannel coal at Avon, and was worked by the Avon Coal Com- 

 pany, in connection with the coal, and they were thus enabled to manufacture 

 the fire brick required for their own furnaces. At Andrews's coal bank, two 

 miles and a half north of Marietta, there is from two to three feet of good fire 

 clay below the coal, and at many other localities in the county, especially in 

 connection with the lower coals, clays suitable for pottery or fire brick may be 

 obtained. 



Iron Ore. Iron ore, in considerable quantities, was met with at several lo- 

 calities in the county. In the vicinity of Seaville there is a bed of limonite, 

 from eight to twelve inches thick immediately above the limestone that forms 

 the roof of the lower coal. This ore closely resembles that at Chadsey's place, 

 in Schuyler county, an analysis of which is given in the report on that county, 

 in the preceding chapter, and it holds about the same stratigraphical position. 

 The same band of ore was seen in the vicinity of Avon, and it probably extends 

 over a large area in the county. In the vicinity of Utica, there is a considera- 

 ble amount of impure carbonate of iron, occurring in regular layers of nodules, 

 or kidney shaped concretions, disseminated in bands through a bed of clay 

 shale, from fifteen to twenty feet in thickness. The bands of ore are from two 

 to three inches thick, and are separated by from two inches to a foot in thick- 

 ness of shale, and the aggregate thickness of this ore at this locality, would be 

 from three to four feet, and it would probably yield from thirty-five to forty 

 per cent, of iron. The shale in which this ore is embedded, is probably the 

 shale over coal No. 3, and if so, an abundant supply of coal could be obtained 

 on the spot, either from that seam, or No. 2, which lies from forty to fifty feet 

 below it. The roof shales of coals Nos. 4 and 5, abound in large ferruginous 

 concretions, but they are generally too strongly charged with pyrites to be of 

 any value for the iron furnace. Iron ore is almost universally disseminated 

 through the Coal Measures in this State, but usually in too small quantities to 

 be of any great value for the production of metallic iron, but it is quite proba- 

 ble that the ores of this county may at some future time, become valuable for 

 this purpose. 



Buildinfj Stone. The Coal Measures seldom afford large bodies of lime- 

 stone of sufficient thickness, and of the right quality for good building 

 stone, and this material has to be mainly supplied from the sandstones, which 

 are usually the prevailing rock in the coal regions. There are some beds of 

 limestone, however, in this county, that furnish a suitable material for rough 

 walls, though the supply is quite limited. The limestone that immediately 



