MACorrix COUNTY. 301 



and affords a coal of very good quality. Xo. 9 immediately underlays 

 the Carlinville limestone, but in this county seems to be .scarcely devel- 

 oped at all, and is usually represented by a thin bed of bituminous 

 shale, locally containing fossil ferns in considerable abundance. Xo. 

 10 was found only six inches thick in the Virden shaft, but in the 

 bluffs of the Macoupin, east of Carlinville. it is from twelve to eighteen 

 inches in thickness, but poor iu quality where it outcrops. Xo. 11, 

 in the same vicinity, is only one foot thick at its outcrop, and I 

 could not learn that any attempt had been made to work it iu this 

 county. Xone of these seams are likely to be found thick enough in 

 this portion of the State to be of any economical importance, so long as 

 the vast resources from the lower seams remain unexhausted. 



Economical G e o I o g ij . 



Coal. As may be proumed from the perusal of the preceding pages, 

 coal is by far the most valuable mineral product of this county. Its 

 entire area is underlaid by coal, and the supply from coal seam Xo. 5 

 alone is practically inexhaustible ; and its resources from this seam, 

 reckoning its average thickness at six feet, which I believe to be a 

 fair estimate, is not less than .">. 184,000,000 tons, and will admit of an 

 annual consumption of one million of tons per annum for 5,184 years 

 before the coal from this seam alone would be exhausted. The under- 

 laying beds which have never yet been penetrated in this county, and 

 probably will not be until Xo. 5 has been thoroughly worked out along 

 the railroad lines, may be safely set down as capable of affording an 

 amount equally as great as that from Xo. 5. and hence the entire coal 

 .irces of this county may be estimated in round numbers at more 

 than ten billions of tons. 



( oal Xo. 5 may be found a ny where in this county that it may be 

 desirable to inaugurate a coal mining euterprize, as it outcrops at the 

 surface on the principal streams that intersect the western border of 

 the county, and iu the central and eastern portions it may be reached 

 in shafts varying from three to four hundred feet iu depth. Its depth 

 below the Carliuville limestone varies from two hundred to two hund- 

 red and twenty feet in the county, and where this limestone is exposed, 

 or where it is known to form the bed rock, the distance to the coal, and 

 the approximate cost of opening a mine in it, can be readily deter- 

 mined. 



( Hal Xo. 4 usually lies from thirty to forty feet below Xo. o, and the 

 three lower seams. Xos. 1. ~2 and 3, will all be found, if developed at all, 

 within one hundred and fifty -feet below Xo. 4. so that a boring or shaft 

 carried two hundred feet below the main coal in this county, would 



