KNOX COUNTY. 321 



coal strata in the Illinois river valley, as given in the third volume of these 

 reports, and that the others are the equivalents of coals No. 2 and 3 of the 

 same section, to which they correspond more decidedly in their general fea- 

 tures than with the higher beds. They are, however, considerably thicker 

 here than coals Nos. 2 and 3 average in other portions of the State, but as the 

 local thickening of the coal is not an uncommon occurrence, no definite con- 

 clusion can be based on that character alone. It may be, however, that the 

 lower coal in the above section will prove to be No. 2, and that the beds above 

 either represent coals 3 and 4, or an unusual local development and division 

 of No. 3 only. If this proves to be the true solution of the question, it shows 

 that the fossil plants usually found in the roof shales of No. 2, also occur some- 

 times in connection with the higher seams. 



The lower coal in the above section is also worked in township 9, range 1, 

 section 17, and the mines in section 36 probably belong to it. The seam there 

 is about three feet thick. In township 9, range 2, it is worked in sections 6, 



8, 9, 27 and 31. Along the little run that intersects the western part of sec- 

 tion 31, a coal that appears to be the same has been worked high up in the 

 bluff, and in the bed of the run the lower coal, No. 1, crops out. 



No. 2 is worked either by stripping or drifting. Along the bluffs of the 

 streams and in the hill-sides where it crops out, it is frequently the case that 

 but a few feet of other material lies over it, and by stripping this off, large 

 amounts of coal are obtained at a small expense. At no place in the county 

 is this seam worked by means of a shaft, but in those parts where it attains a 

 thickness of from two and a-half to three feet, it may hereafter be profitably 

 worked by this method. 



The lower seam, No. 1, is not worked to any extent in but one locality in 

 Knox county, on section 21, township 12, range 1. It is here worked by 

 means of a shaft, which is about thirty feet deep. The coal is six feet thick, 

 but as much of the roof is not very firm, and the upper part of the coal is of 

 inferior quality, from one to two feet of coal is left to strengthen the roof. In 

 section 36, township 9, range 1, this seam has been found several feet below 

 the bed of the little stream that passes through it. In section 31, township 



9, range 2, it crops out in the bed of a small run, and a little coal has been 

 taken out here. South of this, and just over the line in Fulton county, the 

 strata exposed in the bluff of Cedar Fork show the following section : 



FEET. IN. 



1. Clay shale. Not measured 



2. Coal No. 2, about 3 



3. Shale and slate 35 to 40 



4. Coal, upper division of No. 1 10 



5 Shale 8 in. to 1 2 



6. Sandstone 6 " 9 



41 



