about 200 feet deep, which, with the lower entrance or portal, gave sixteen working faces.  Diamond drills were used at the lower heading requiring power; the other fifteen headings were driven by hand-work.  It was uncertain how much water would be encountered; but from the location, it was evident that a large quantity might be struck in any shaft, and hence it became necessary to have ample power at hand at each opening, in readiness for such an emergency.  A pipe main was laid along the general line of the tunnel, with its pen-stock 285 feet vertical above the surface at the upper shaft, and 549 feet above the lowest shaft.  It was made of single riveted sheet-iron, of No. 14 (Birmingham) gauge, in lengths of 20 feet, put together stove-pipe fashion, with the joints made tight by cloth tarred strips and pine wedges.  This pipe had a diameter of 15 inches at the pen-stock, diminishing from this to 13, 11, and 7 inches at its lower end.  From it, short branches, 7 inches in diameter, were extended to the several shafts.  It was in one place carried across the stream by a light suspension bridge, some 150 feet long, the trunk of a tree on each side forming a convenient tower.  The aggregate length of the main and branches was 9,960 feet, with some 2,500 feet additional, for the branch to the diamond drills.  The pipe was laid on the surface of the ground, its only protection being in places a couple of 11/2-inch planks tacked together, and placed over it; the range of temperature was from 10 degrees to 107 degrees Fahr. (in the shade).  It was inspected by the foreman of the tunnel-work as he daily walked over the line; besides the occasional driving of a few wedges and putting on a band or two, it gave no trouble from leakage, which probably for its entire length did not amount to more than an average of 3 or 4 cubic feet a minute; from time to time, a little sawdust was put into the pen-stock.  Three stop-gates were placed on the main, and a separate stop-gate at each shaft, operated by a fine-threaded screw, so that the water could be cut off when desired.

[Illustration:  FIG. 13.]

Fig. 13 shows the arrangement of the machinery for hoisting and pumping, which was identical at the several shafts, except that the hurdy-gurdies varied from 161/2 feet in diameter at the upper shaft to 21 feet at the lowest shaft.  The water-wheel moved only in one direction; the pinion on the wheel-shaft drove the spur-wheel, to which the pitman of the pump-bob was attached.  On the spur-wheel shaft was a friction-gear, driving the hoisting-reel; this reel was mounted on sliding blocks, so that hoisting was done by putting it in gear, the empty load being dropped by a friction-band.  Changing the size of the water-wheel as the pressure increased permitted the use of the same pattern of machinery at the different shafts.  The water was brought to the wheel by a discharge-pipe, some nine feet long, having a vertical movement by ball-and-socket