"I don't see how you can work so fast," declared Bucks. "Do you know how many times," demanded the spiker, "those sledges have to swing? There are eighteen ties and thirty-six spikes to every rail, three hundred and fifty-two rails to every mile, and eighteen hundred miles from Omaha to San Francisco--those sledges will swing sixty-eight million times before the rails are full-spiked--they have to go fast." The words were hardly out of the chief spiker's mouth when a cry of alarm rang from the front. Bucks, looking eagerly, saw in the west a cloud of dust. At the same time he saw the tie gang running in dozens for their lives from the divide where they were working toward the camp. The men beyond them on the grade had scrambled into the wagons, dumped any ties they might contain helter-skelter to the ground, and were clinging to the wagon boxes. In these, the drivers standing up, lashed their horses with whip and line for life, and death, while everywhere beside and behind them other men on foot were racing back to safety. New clouds of dust rose along the grade from the flying wagon wheels, the horses tore madly on, and as the heavy wagons jolted over the loose stones, the fugitives, yelling with excitement and alarm and clinging to one another as they bounced up and down, looked anxiously behind. There was no uncertainty as to the cause of the panic. "Indians!" was the cry everywhere. Every man in camp had dropped his working implement and was moving somewhere on the double-quick. Every one, it seemed to Bucks, was shouting and running. But above the confusion of the surprise and the babel of voices, Bucks heard the sharp tones of Jack Casement giving orders. The old soldiers in the working gang needed no further discipline. The timid and the skulkers scurried for the box-cars and the dugouts. On the other hand, the soldiers ran for the dumps where the arms were stacked, and seizing their muskets hurried back and, trained for the emergency, fell into line under their foremen. Casement, musket in hand, taking the largest company of men as they formed in fours behind him, started forward at the double-quick, yelling now for the moral effect, to protect the retreat of the wagons. The men, scattering as they reached the edge of the camp, dropped into every spot of shelter, and at the same moment Stanley, mounted and alive with the vim and fire of the soldier, led a smaller body of men rapidly back to guard the rear of the camp, deploying his little force about the box-cars and flat cars as they hastened on. In an instant the construction camp had become a fortress defended by a thousand men.