182 GEOLOGY OF ILLINOIS. 



JE c o n o mi c a I Geology. 



Coal. From what has already been said, in speaking of the coal 

 seams and their outcrops, it will be seen that the coals of Bureau county 

 are an important element of county wealth, and minister largely to the 

 convenience and well-being of its citizens. I have no means of estima- 

 ting the present amount of coal mined each year in the county. The 

 Sheffield mines have been worked since 1853. Two hundred and fifty 

 thousand tons of coal are supposed to have been mined and sold during 

 that time at these mines. They are being worked extensively at the 

 present time, and their supply is by no means exhausted. Thousands 

 of tons have doubtless been taken out by farmers and land owners, in 

 small quantities at a time, of which no account has been rendered. The 

 coal field actually known to exist here has hardly commenced to be 

 worked over, and may be found to extend much farther east, south and 

 west than is now supposed. 



The Buda shaft is worked strong enough to employ a steam engine, 

 and is yielding at the present time a large amount of good coal. Other 

 shafts, in course of time, will be put down here. There is evidence that 

 coal underlies several miles in extent of surface around the grove where 

 the present mine is worked. The necessities of the country, and the 

 ease with which shafts reach this good workable seam, insure more ex- 

 tensive operations at this locality. By the Buda shaft I refer to the one 

 between that place and Wyanet. 



Almost the same can be said of the locality at Bierman's shaft, I 

 am satisfied this is a valuable field of coal ; of considerable extent ; of 

 easy access. It will be worked extensively at an early day, and will 

 afford a large supply of excellent coal. 



The Tiskilwa coal banks are old banks, having been worked for many 

 years. The amount of coal taken therefrom is not known ; but they 

 have at no time been worked as strongly as the mines at Sheffield, and 

 the supply of coal has been much less. I am uncertain as to their future 

 productiveness. For a time they were considered as partially worked 

 out ; but the heavy seam found in the new bank of Messrs. Jobling, 

 Sleeter & Snowdon seems to show that the supply of coal is by no 

 means exhausted. This discovery will probably add a new impetus to 

 coal mining in this locality. 



There are many other localities in the south-western and south-eastern 

 portions of the county where shafts sunk to a moderate depth would 

 strike coal from four to five feet thick. Along and among the Illinois 

 river bluffs there is no reason why valuable coal deposits may not be 

 found. Borings along the base of these bluffs ought to disclose the 

 middle and even lower Peru coal seams ; and if the ravines were care- 



