KANKAKEE AND IROQUOIS COUNTIES. 231 



nected the northeastern portion of the Illinois coal field with that of Central 

 Michigan, and have drifted hither from the east and north. Much of the 

 black shale, however, probably came from the outcrop of the Devonian (or 

 Sub-carboniferous ?) bed of that material which outcrops so widely through 

 Northern Indiana. 



Coal Measures. As already indicated, the Coal Measures are confined to 

 the extreme western portion of the county. Their eastern boundary enters 

 the county from the north near the center of section 5, township 31 north, 

 range 9 east, runs due south nearly three miles, then bears a little westward, 

 and near the center of the west line of township 30 north, passes into Livings- 

 ton county. Explorations have not yet been made to such an extent as to in- 

 dicate more exactly the southern part of this line ; but its general correctness 

 has been proved, since its location, by finding that its continuation southward 

 passes directly across the known edge of the field, at Chatsworth, in Livings- 

 ton county. Along the northern part of the line, numerous borings have been 

 made, and a few shafts sunk. The only ones now furnishing coal are, Hook's, 

 and Gamble's shafts, in section 8, and Conklin's shaft, in section 19, of town- 

 ship 31 north, range 9 east. Hook's shaft is sixty-thr.ee feet deep to the coal, 

 with the following section : 



FEET.' IN. 



1. Soil and sandy loam 4 



2. Brownish clay, with cobble-stones 4 



3. Blue boulder clay 30 



4. Bluish clay shales 25 



5. Coal 2 10 



6. Fireclay 2 



7. Sandstone. 6 



At Gamble's shaft, which is a little shallower, Nos. 2 and 3 of the foregoing 

 section are wanting ; and the shales of No. 4 continue up to the sandy subsoil. 

 All of these mines find the coal of pretty uniform thickness, and furnish a good 

 clean coal, well fitted for domestic use and for steam fuel. Their product is 

 all delivered to wagons, for the local supply of the country to the east and 

 southeast of the mines ; and the extent of the coal field in this county is so 

 small as to render it doubtful whether a railroad will ever be so built as to give 

 them outlet to a larger market. 



The seam is the continuation of that so largely mined about Morris, in 

 Grundy county, and in the lower corner of Will county, namely, " No. 2," of 

 the Illinois valley section. As in the adjoining part of the field, the limit of 

 the seam is quite irregular, the numerous borings having shown that, at some 

 points, currents have washed away the coal, so as leave deep depressions in its 

 outline ; and at others, projecting and even isolated patches of the seam are 

 found outside of the general boundary. In the latter case, the seam is some- 



