pillars of coal—of course beginning at that part of the mine farthest away from the shaft, for the roof tumbles in as they are cut, one by one, away. Dangerous work this. The other mine sinks a perpendicular shaft eight or liiiie hundred feet deep, and of course a leaf distance off from the out-crop. The b-vels strike off from the foci of this, and the mining is carried oa in the same manner, ex