The blacksmith's tunnel--the tunnel leading off from the level--was blocked by fallen timbers where a belt of lime formation cut across; and fragments of wood, splintered into toothpick size, had been thrown out when the mountain settled to its place. But a short distance from the main shaft, which was a double compartment, carrying two cages up and down, in every level the air was foul down to the five-hundred foot, and below that the mine was filled with water. Patiently Dick and the veteran explored these windings as far as they might until the guttering of their candles warned them that the air was loaded with poison, and often they retreated none too soon to scale the slippery, yielding rungs of the ladder with dizzy heads. Expert and experienced, they were puzzled by what was disclosed. Either the mine had yielded exceedingly rich streaks and had been, in mining parlance, "gophered," or else the management had been as foolish as ever handled a property. In the assay-house, where the furnaces were dust-covered, the scale case black with grime, and the floor littered with refuse crucibles, cupels, mufflers, and worn buckboards, they discovered a bundle of old tablets. Almost invariably these showed that the assays had been made from samples that would have paid to work, but this alone gave them no hope. But this was not all. A mysterious enmity seemed to pursue all their efforts. Yet its displays were unaccountable for by natural causes. On their arrival at the mine they found water, fresh and clear, piped into every cabin, the mess-house, and the superintendent's quarters. They traced it back and discovered a small lake formed and fed by a large spring on what was evidently land of the mine. It suddenly failed them, and proved unwholesome. An investigation of the tiny reservoir disclosed masses of poisonous weeds in the water. They decided that they must have been blown there after their arrival, cleared the supply and yet, but two days later, when there had been no wind of more than noticeable violence, the weeds were there again. They abandoned their water supply for the time being and resorted to the stream at the bottom of the canyon. A day later one of their burros died mysteriously, and Bill, puzzled, said he believed that it had lost its sense of smell and eaten something poisonous. On the day following the other died, apparently from the same complaint. The veteran miner grieved over them as for friends.