"To the Ruby Mountain?" inquired Tad meaningly.
"Yes, most probably that far, or pretty close to it, I should say; but I have never made a measurement with that in view, so that I am unable to give you a definite answer. We should have to bore through some pretty solid rock to get under the little red mountain, I'm inclined to think."
"I'd like to go over that way."
"All right, we will visit that part of the drift later," replied
Mr. Phipps.
What Tad's motive might have been in wishing to get under the Ruby Mountain, perhaps he himself did not know. But he did know that somehow he felt that before leaving the mining camp he would solve the mystery of the place.
They first followed the drifts to the west where here and there a dull distant report told them the miners were blasting out the rocks with dynamite. After being broken up into large chunks the ore was placed on little cars and run along tracks to the hoisting apparatus from where it was quickly shot to the surface.
It was a busy scene that the Pony Rider Boys found—a different world from the one they had just left above them.
"Do these mines ever blow up or catch fire?" asked Walter a bit apprehensively.
"No, we have no fires of any consequence. We have never had an explosion and I trust we never shall," answered the assistant superintendent gravely. "You see there is not the same danger in this sort of place that you find in a coal mine. I would prefer to work digging out dynamite to mining coal."
"Dynamite? Do you keep much of it down here?" interrupted the
Professor.