"The reservoir is filling a great deal faster than I supposed it would," he said, bearing his companion resolutely away from the painful things.
"There have been storms on the main range all day," was the reply. "Father has a series of electrical signal stations all along the upper canyon. He said at the dinner-table that the rise to-night promises to be greater than any we have ever seen."
Ballard came alive upon the professional side of him with a sudden quickening of the workaday faculties. With the utmost confidence in that part of the great retaining-wall for which he was personally responsible--the superstructure--he had still been hoping that the huge reservoir lake would fill normally; that the dam would not be called upon to take its enormous stresses like an engine starting under a full load. It was for this reason that he had been glad to time the closing of the spillway in August, when the flow of the river was at its minimum. But fate, the persistent ill-fortune which had dogged the Arcadian enterprise from the beginning, seemed to be gathering its forces for a final blow.
"Cloud-bursts?" he questioned. "Are they frequent in the head basin of the Boiling Water?"
"Not frequent, but very terrible when they do occur. I have seen the Elbow toss its spray to the top of this cliff--once, when I was quite small; and on that day the lower part of our valley was, for a few hours, a vast flood lake."
"Was that before or after the opening of your father's mine over yonder?" queried Ballard.
"It was after. I suppose the mine was flooded, and I remember there was no work done in it for a long time. When it was reopened, a few years ago, father had that immense bulkhead and heavy, water-tight door put in to guard against another possible flood."
Ballard made the sign of comprehension. Here was one of the mysteries very naturally accounted for. The bulkhead and iron-bound door of the zirconium mine were, indeed, fortifications; but the enemy to be repulsed was nature--not man.
"And the electric signal service system in the upper canyon is a part of the defence for the mine?" he predicated.
"Yes. It has served on two or three occasions to give timely warning so that the miners could come up and seal the door in the bulkhead. But it has been a long time since a cloud-burst flood has risen high enough in the Elbow to threaten the mine."