194 GEOLOGY OP OHIO. 



ing through the fisBures in the limestone, has worn the rock into irregu- 

 lar shapes. Throughout this distance the bed is cut up by many clay 

 "horsebacks," thrust up from below, while the coal is so crushed and dis- 

 torted as to be utterly worthless. The shaly layer, No. 7, is much slick- 

 ensided, and No. 10 is a mass of slaty, slickensided material, which is not 

 removed. The upper coals, Nos. 3 and 5 of section, are good and clean, 

 showing little tendency to run, and bear a decided resemblance to the 

 Briar Hill Coal. Nodules of pyrites occur in these layers, but are not 

 large or numerous, and are easily separated. The black shale. No. 7, 

 which is quite compact, has thus far proved a very serious drawback, 

 maintaining a thickness of seven inches along the entry, which, when 

 visited, had been driven one hundred and fifty yards. It seems, however, 

 to diminish eastward, being only three inches thick in a room opened in 

 that direction. No. 8 seems to be of good quality, but shows a decided 

 tendency to cake upon the fire. Specimens from this bank give the fol- 

 lowing upon analysis : 



UPPER BEKCH. LOWER BENCE. 



Specific gravity. 1.287 1.285 



Moisture 2.30 2.50 



Ash 4.90 6.60 



Volatile combustible matter 35.90 36.70 



Fixed carbon ,S6.90 54.20 



Total 100.00 100.00 



Sulphur 2.03 2.33 



Sulphur left in coke 0.98 1.01 



Sulphur forming of the coke 1.58 1.66 



Fixed gas per pound, in cubic feet 3.40 3.48 



Ash White. Gray. 



Coke Compact. Compact. 



In prospecting to determine the value of Coal No. 4, Messrs. Tod, 

 Stambaugh & Co. made a number of borings, placing the work in charge 

 of Mr. John Young. A table of the sections exhibited is given on the 

 opposite page. These sections afford an interesting view of the changes 

 which strata undergo within very limited distances. The whole area 

 represented is about one hundred acres. Throughout, Coals Nos. 5 and 

 4 maintain the same interval, or nearly so, showing that the disturb- 

 ance, whatever it may have been, causing so marked variations in the 

 distance between 4 and 3, must have occurred before the deposition of 

 the rocks overlying the latter. This case is very similar to one reported 

 by Mr. Read in Vol. I., page 498, showing that the rate of subsidence was 

 not equal in all parts of the coal field, or even within limited areas. 



