cept that the first is carried dOamspsßtl from the surface, and this is carried from the bot tom of the shaft upward toward the out-crop. The foot of the shaft is the deepest part of the mine. Of course thane levels cannot always be psralett. or eo^ui-distant, or. the intersecting drifts straight and at right angles. The varying dip of the strata, the disappearance of some veins, tho discovery of others, and, most of all,