Calling to the boys above to cling tightly to the rope and to pay it out slowly, Nestor slid swiftly downward until the slack of the line was gone, and was then brought up with a quick jerk, with the still slipping boy's head a foot away from his hands. He whirled about and dropped his feet down the passage.
There was a second of nervous strain, and then he felt Jimmie's hands clinging to his shoes. He called to the boy to hang on and to the others at the top to draw the line, and both were soon on the landing at the bottom of the shaft.
"I wonder where that hole goes?" Jimmie asked, examining his fingers, the ends of which were torn from slipping on the rock.
"You came near finding out," Nestor replied. "Regular rabbits, these old-timers were, to dig tunnels!" he added.
Then assisting Jimmie out of the shaft, Nestor asked the boys to get all the rope they had in their outfits, making a line as long as possible, and ease him down the steep incline. In five minutes all was ready and, with a line 400 feet long attached to his waist, Nestor started down the tunnel.
As he passed along, half sliding, with the rope holding him back, the flashlight in hand, he saw that the passage had been cut along the line of a natural fault in the volcanic rock. It was clear that, during some seismic disturbance, probably hundreds of years before, the continuity of strata, until then on the same plane, had been broken, leaving a fissure where the drop had taken place.
There was no means of estimating the extent of the vertical displacement, but the boy was satisfied that it was the difference between the height of the range at the place where the cavern opened and the height to the north, probably three hundred feet or more. The north end of the range had dropped down. The horizontal displacement was not more than six feet, and it was through this that the tunnel ran.
The walls of the passage were smooth, and the floor was like polished glass, a fact which the boy was at first at a loss to account for. On the north side the wall was dark and there were no traces of gold, while that on the south showed spots of precious metal.
Nestor proceeded down the incline until there was little more rope left, as the boys called out from above, and then came to an opening. He was now nearly 400 feet from the gold chamber.
When he looked out of the round opening to which he had come he saw that beyond ran a deep gully, or canyon. At the point where the opening cut the wall of the canyon, however, there was a gradual descent for perhaps 400 feet to the bottom of the break in the mountain.
Elsewhere the walls of the canyon seemed to stand perpendicular, and Nestor was for a moment puzzled to account for the filling of the break at that particular spot, as if a rude stairway had been laid to the ground below. Then the truth flashed upon him.
The tunnel had been built as a chute for the disposition of the rock crushed in the mine.
There was no knowing how many years the natives had worked in that underground mine, crushing out the gold with rude appliances and disposing of the refuse by means of the tunnel cut through the fault in the rock. The canyon into which the crushed rock had been cast was a wild and almost inaccessible break almost at the top of the mountain range, and might have been used for years--perhaps for centuries--without the truth of its gradual filling up becoming known to hostile peoples.
