178 GEOLOGY OF ILLINOIS. 



inferior quality. The shaft is used in mining coal in the lower seam, 

 tlir drift tor mining the upper one. 



Section thirty-two, in the township of Center, is said to show eviden- 

 ces of coal, but as no coal mine is worked there, no examination was 

 made of the place. 



Following on southeast in the same general course, the next coal of 

 workable thickness is found in Coal Valley and Rocky Run, near Tiskil- 

 wa. These mines have been worked for many years. Two or three drifts 

 have been worked out and abandoned. There seems to be three coal 

 seams at this locality. The lower one has only been found in the boring 

 made for an artesian oil well, at a depth of one hundred and fifty -nine 

 feet below the surface of the ground, at the mouth of the well. It has 

 not been worked, and in the present state of coal mining in this part of 

 the State is of no practical value. The seam is thin ; access to it is dif- 

 ficult ; its existence was only accidentally disclosed by the oil well boring, 

 of which a section has already been given. 



The next seam, called by the miners the middle Tiskilwa seam, is 

 worked in many places. The mines are about half a mile farther up the 

 stream, on the left bank or bluff of Coal creek ; the entrances to the 

 drifts are fifteen or twenty feet above the level of the water in the little 

 brook, and still more than that above the mouth of the oil well. I can- 

 not tell the distance between the lower and middle coal seams here, but 

 judge it to be from one hundred and eighty to two hundred feet. The 

 principal drift into this seam has been worked a long time, mostly by 

 Messrs. Churchill & Shaw; the mine is nearly worked out and is aban- 

 doned at the present time. At the time I was there Messrs. Jobliug, 

 Sleeter & Snowdon had just completed a new drift a few hundred 

 yards above the old one ; had struck the seam at a distance of one hun- 

 dred and eighty feet under the hill, if I recollect right, and, so far as 

 could be judged at that time, they were opening a very valuable mine. 

 I have since heard that this mine is turning out an abundance of good 

 coal. The seam is five feet thick. It can be easily drained ; there is a 

 fair roof of black slate ; below there is the usual bed of ordinary fire 

 clay. In some places soapstone takes the place of the black slate 

 roof. 



This is doubtless the seam of coal from which the analysis was made 

 by Mr. PRATTEN, while acting as Assistant in the Illinois Geological 

 Survey. The following is his description and analysis ; 



"This bed is of the same age as the middle (!) workable seam of 

 LaSalks county, and like that bed is frequently in terrupted with, clay 

 "slips." The portion of the bed examined is on L. D. WHITING'S place. 

 Coal very bright, hard, compact 5 layers generally thick, and separated 

 with carbonaceous clod, sometimes nearly indistinct; fracture conchoidal. 



