“That is quite immaterial,” was the cool-voiced reply. “The measures vary in thickness, though not greatly. Geology is one of my small side-lines, Mr. Carfax, and I have made a study of this particular region, largely as a pastime.” The sight-seers were straggling back, and Tregarvon was explaining to a group of breathless maidens just where he had been sitting with Carfax at the moment of catastrophes, and how Rucker had been knocked down by the wind of the fragment which had struck the corner of the tool-shed. Carfax saw his opportunity preparing to take its leave and he smiled, level-eyed, at Hartridge. “You are still on the obstructive hand, aren’t you?” he threw in. “Even now, you would like to discourage us if you could.” The professor of mathematics and other things was turning away to join the others, but he paused for a low-toned rejoinder. “I neither deny nor affirm, Mr. Carfax. But I may say this much: if I were in your shoes, or Mr. Tregarvon’s, I shouldn’t call to-day’s disaster a pure accident--until I could prove it.” And with that he turned his back and began to talk to the art teacher. XVIII Evolutionary Intent upon the swift purchase of another power-plant, Tregarvon caught an afternoon freight on the branch railroad, made a late train on the main line, and was obliged to spend the Sunday in Chattanooga, with little to console him save the thought that he would be on hand to transact business with the machinery merchants bright and early Monday morning. It was a sad Sunday, weatherwise, with a chill autumn rain sweeping the streets of the battle-field city, and the crest of Lookout Mountain veiled in cloud. Tregarvon had made a few business acquaintances in town on previous purchasing expeditions, but there were no familiar faces in the hotel; nothing to lighten the monotony of a dreary day of enforced idleness. In such circumstances impatience becomes a rat to gnaw the vitals. The suspense, the tormenting uncertainty which he had left behind him in the unfinished test-hole on the summit of Mount Pisgah, would have been hard to endure even in a whirlwind of work; and upon a day when he could neither work nor play he was in despair.