THE LOWER COAL MEASURES. 227 
As in the Block coal fields generally, the Palmyra coal lies in 
narrow troughs or swamps, the length of which is considerable in pro- 
portion to the breadth. In this field the troughs are often very narrow, 
and never exceed 200 yards in breadth. They are somewhat sinuous, 
but the general direction is northeast and southwest. Mr. EK. T. Bowen, 
the intelligent manager of the Palmyra Coal Company, has observed 
that whenever a sharp deflection in the course of the swamp occurs, 
there is a good body of coal to be found’ in the concavity of the curve. 
It would be hard to state the average thickness of the coal. Three 
feet are assumed as the normal thickness of the seam, and for mining 
all coal below that, a larger price is paid per ton. The coal is worked 
down to 2 feet, and sometimes to 13 feet. The coal in the Black 
Diamond mine is a trifle stronger than in the other banks. In a con- 
siderable part of the Scott mine it is thinner than elsewhere. In the 
Palmyra and the Black Diamond mines, a thin “ bone” coal comes in 
at the top of the seam, but in the Scott bank this develops into a semi- 
cannel, 13 feet thick. It is called Splint coal, and market has been 
found for it to some extent. It has even been sold at a higher price 
than the block coal. 
The normal section of the seam is 3 feet of clean and undivided 
coal, but this structure is varied in several ways. Frequently there is 
23 feet of coal, overlain by a 4-inch slate, over which 8 inches of slaty 
eannel occurs (No. 1, Fig. XXXIV). Again, the true coal may 
be reduced to 12 or 14 inches, with 2 feet of cannel overlying it (see 
No. 3 of figure). All these facts are shown in Fig. XXXIV: 
FAG VU RE XACK A 
STRUCTU RE OF SHARON COAL AT PALMYRA. 
These several phases occur in different entries of the Scott mine. 
The cannel has a brecciated structure at times. The thickest coal ever 
