The stranger was dressed like a mechanic; and he seemed to be examining the planking of the bridge, which is not usually a matter of vital importance in such a structure for railroad purposes. The man stopped whistling, and began to use a middling-sized sledge-hammer, directing his blows at the heads of the spikes under his feet. Then he dropped the hammer, and picked up an adze, with which he trimmed off the projecting edge of a plank. Deck thought this was very strange work for a man to be doing at such a time, and in such a place. But the mechanic was whistling a Union air; and this fact seemed to make it all right, and prevented him from having a suspicion that all was not right in the presence of the man on the bridge. The railroad in Kentucky was a loyal institution, as it was a disloyal one farther South. Deck therefore came to the conclusion that he was an employee of the company. He decided to interview the stranger, and ascertain more precisely who and what he was. In matters of military duty Deck was a close constructionist; and the first question he asked himself was whether or not he ought to leave his post, even to go a distance of forty feet. His sole occupation till he received the signal to hoist the flag, was to watch for it; and he kept his father's plumed hat in sight all the time. But he could see the handkerchief when it was waved as well from behind the fence as at the flagstaff; or, at most, he had only to step back a few paces to enable him to command a full view of the expected battle-ground, and of the hill behind which Captain Truman was posted with his command. He did not for an instant lose sight of his sole duty; but he walked a few paces at a time towards the fence, and then looked back, to make sure that he could see the plume of the major. As it was in sight all the time, he continued to advance very slowly. When he reached the end of the fence the centre of his watch was still to be seen, and nothing seemed to be in progress in any of the roads visible from his position. Just at the moment when he was almost within speaking distance of the mechanic, who had ceased to whistle, the latter picked up his tools and moved to the other end of the fence, where he began to hammer the spikes again. The man appeared to take no notice of him, or even to be aware of his presence. Assured that he could see the skirmishers who had been sent beyond the hill if they were driven in, he continued to advance still farther, though he went to the middle of the bridge, where the fence did not obstruct his view.