4^6 Coal Mines of Virginia. 



the granite, and I can discover no very good reason for disa- 

 greeing with them in this particular ; but, on the contrary, 

 many circumstances concur to strengthen the opinion that it is 

 I'eally coextensive with the granite. The coal is now pro- 

 cured from at least 25 different pits, opened at convenient dis- 

 tances through an extent of from 60 to 70 miles. It every 

 where commences at the upper surface or termination of the 

 body of granite. Some suppose that it is imposed on the gra- 

 nite ; and others, that a thin stratum of slate is interposed be- 

 tween the coal and granite. It is always found covered by 

 the slate. The granite is inclined to the horizon at an angle 

 of 45°, and the coal has the same inclination. And since the 

 coal, as far as it has been discovered, is found to accompany 

 and correspond with the granite, why may we not suppose 

 that it continues to accompany the granite, where it has not 

 yet been discovered ? At Heth's pits, the coal is 50 feet thick, 

 measured on a line perpendicular to the surfaces of the ex- 

 treme strata. At some of the pits between Heth'^ and James' 

 River, it is 30 feet thick ; and at the river, not more than 25 

 feet. The thickness of the coal on the north side of James" 

 River, at the pits in Henrico and Hanover counties, is variable, 

 but at no place greater than 26 feet ; and to the south of 

 Heth's, in the pits extending to the Appomatox river, it is still 

 less thick. These facts would induce the supposition, that the 

 coal was deposited in a bed, near the centre of which Heth's 

 pits were sunk. But, on the other hand, the. coal is distinctly 

 stratified, and the number of strata increases as the coal pro- 

 ceeds from the surface of the earth ; of course, therefore, the 

 farther you proceed from the outer extremity of the coal, the 

 thicker the body of it will be found ; and from the inclination 

 of the coal, the farther you are from its outer extremity the 

 deeper it must be under the surface of the earth. Heth's pits 

 are 100 feet deeper than any that have yet been sunk ; and 

 all the pits, that I have seen, appear to be nearer to the outer 

 extremity of the coal. We may conclude, therefore, that if 

 the others had been sunk as far from the outer extremity, they 

 would have been as deep, and the coal would have been found 

 as thick ia them as in Heth's. Heth's pits, now so called, 



