Mrs. Whitney wondered why, if Mr. Glover were really a competent man, he could not have held his position as chief engineer of the system, but Doctor Lanning explained that frequently Western men of real talent were wholly lacking in ambition and preferred a free-and-easy life to one of constant responsibility; others, again, drank—and this suggestion opened a discussion as to whether Western men could possibly do more drinking than Eastern men, and transact business at all.

While the discussion proceeded there came a telegram from Glover telling Doctor Lanning that the blast would be made about seven o'clock. Preparations to start were completed as the company rose from the table, and Gertrude Brock and Marie were urged to join the party. Marie consented, but Gertrude had a new book and would not leave it, and when the others started she joined her father and Judge Saltzer, her father's counsellor, now with them, who were dining more leisurely at their own table.

Bucks met the doctor and his party at the head of the cañon and took them to the high ledge across the river, where they had been brought by Glover in the morning. In the cañon it was already dark. Men were eating around campfires, and in the narrow strip of eastern sky between the walls the moon was rising. Work-trains with signal lanterns were moving above and below the break, dumping ballast behind the track layers. At a safe distance from the coming blast a dozen headlights from the roundhouse were being prepared, and the car-tinks from Sleepy Cat were rigging torches for the night.

The blasting powder in twenty-pound cans was being passed from hand to hand to the chargers. Score after score of the compact cans of high explosive had been packed into the scattered holes, and as if alive to what was coming the chill air of the cañon took on the uneasiness of an atmosphere laden with electricity. Men of the operating department paced the bench impatiently, and trackmen working below in the flare of scattered torches looked up oftener from their shovels to where a chain of active figures moved on the face of the cliff. Word passed again and again that the charging was done, but the orders came steadily from the gloom on the ledge for more powder until the last pound the engineer called for had been buried beneath his feet in the sleeping rock.

After a long delay a red light swung slowly to and fro on the ledge. From the extreme end of the cañon below the Cat's Paw came the crash of a track-torpedo, answered almost instantly by a second, above the break. It was the warning signal to get into the clear. There was a buzz of rapid movement among the laborers. In twos and threes and dozens, a ragged procession of lanterns and torches, they retreated, foremen urging the laggards, until only a single man at each end of the broken track kept within sight of the tiny red lantern on the ledge. Again it swung in a circle and again the torpedoes replied, this time all clear. The hush of a hundred voices, the silence of the bars and shovels and picks gave back to the chill cañon its loneliness, and the roar of the river rose undisturbed to the brooding night.

On the ledge Glover was alone. The final detail he was taking into his own hands. The few that could still command the point saw the red light moving, and beside it a figure vaguely outlined making its way. When the red light paused, a spark could be seen, a sputtering blaze would run slowly from it, hesitate, flare and die. Another and another of the fuses were touched and passed. With quickening steps tier after tier was covered, until those looking saw the red light flung at last into the air. It circled high between the cañon walls in its flight and dropped like a rocket into the Rat. A muffled report from the lower tier was followed by a heavier and still a heavier one above. A creeping pang shot the heart of the granite, a dreadful awakening was upon it.

From the tier of the upmost holes came at length the terrific burst of the heavy mines. The travail of an awful instant followed, the face of the spur parted from its side, toppled an instant in the confusion of its rending and with an appalling crash fell upon the river below.

With the fragments still tumbling, the nearest men started with a cheer from their concealment. Smoke rolling white and sullen upward obscured the moon, and the cañon air, salt and sick with gases, poured over the high point on which the Pittsburgers stood. Below, torches were shooting like fireflies out of the rock. From every vantage point headlights flashed one after another unhooded on the scene, and the song of the river mingled again with the calling of the foremen.

"That ends the fireworks," remarked Bucks to those about him. "Let us watch a moment for Mr. Glover's signal to me. As soon as he inspects he is to show signals on the Cat's Paw, and if it is a success we will return at once to Sleepy Cat."

"And by the way, Mr. Bucks, I shall expect you and Mr. Glover up to the car for my game supper. Have you arranged for him to come?"