238 The Upper Goal Measures 



spared not only the limestone but also the coal, whereas 

 northward both were removed. The eastern boundary of 

 these currents is very tortuous, but has a rudely northeast 

 and southwest direction. They must have their origin in 

 similar causes, as their courses coincide. 



As already stated, the Pittsburg, where accompanied by 

 its normal roof, is a double coal. The roof-coal, or upper 

 division, is subject to much variation. The partings in the 

 lower division are very persistent. About one foot from 

 the top is a band of pyrites, one to two inches thick ; near 

 the middle is a clay parting, about one inch, and three to 

 eight inches below this a second clay parting resembling the 

 first; below this a thin band of pyrites is frequently found, 

 but it is not persistent. The middle bench, between the 

 clay partings, is ordinarily very pure, and well adapted to 

 smiths' use. 



In Millwood and Londonderry townships, Guernsey Co., 

 Ohio, the coal is single-bedded, with a sandstone roof, and 

 varies little from four feet in thickness. In Warren and 

 Kirkwood townships, Belmont Co., wherever roofed by sand- 

 stone, it is single-bedded and badly cut out. In Oxford 

 township, Guernsey Co., the roof-coal is occasionally seen 

 one foot thick and separated by shale from the lower divi- 

 sion . 



Near Deersville, in Harrison Co., the coal is opened and 

 gives the following section : — 



Coal, 10 in. ; clay, 10 in. ; coal, 4 ft. 



The intimate structure of the lower division, as shown in 

 an opening here, is peculiar in the thickness of the middle 

 bench : 



Goal, 1 ft. 6 in. ; pyrites band, 1^ in. ; coal, 2 in. ; clay 

 parting, ^ in. ; coal, 1 ft. 3 in. ; clay parting, 1 in. ; coal, 

 10 in. ; total, 4 ft. 1 in. 



In the neighborhood of these sections the coal is soft, not 

 good for hard firing, but is quite pure and shows few streaks 

 or nodules of pyrites. Followed eastward the coal thickens, 



