A hundred yards away was a straight road, showing white in the moonlight. Endeavoring to orient himself, as a surveyor or navigator might say, the man moved his eyes slowly along its visible length and at a distance of a quarter-mile to the south of his station saw, dim and gray in the haze, a group of horsemen riding to the north. Behind them were men afoot, marching in column, with dimly gleaming rifles aslant above their shoulders. They moved slowly and in silence. Another group of horsemen, another regiment of infantry, another and another—all in unceasing motion toward the man’s point of view, past it, and beyond. A battery of artillery followed, the cannoneers riding with folded arms on limber and caisson. And still the interminable procession came out of the obscurity to south and passed into the obscurity to north, with never a sound of voice, nor hoof, nor wheel. The man could not rightly understand: he thought himself deaf; said so, and heard his own voice, although it had an unfamiliar quality that almost alarmed him; it disappointed his ear’s expectancy in the matter of _timbre_ and resonance. But he was not deaf, and that for the moment sufficed. Then he remembered that there are natural phenomena to which some one has given the name “acoustic shadows.” If you stand in an acoustic shadow there is one direction from which you will hear nothing. At the battle of Gaines’s Mill, one of the fiercest conflicts of the Civil War, with a hundred guns in play, spectators a mile and a half away on the opposite side of the Chickahominy valley heard nothing of what they clearly saw. The bombardment of Port Royal, heard and felt at St. Augustine, a hundred and fifty miles to the south, was inaudible two miles to the north in a still atmosphere. A few days before the surrender at Appomattox a thunderous engagement between the commands of Sheridan and Pickett was unknown to the latter commander, a mile in the rear of his own line. These instances were not known to the man of whom we write, but less striking ones of the same character had not escaped his observation. He was profoundly disquieted, but for another reason than the uncanny silence of that moonlight march. “Good Lord!” he said to himself—and again it was as if another had spoken his thought—“if those people are what I take them to be we have lost the battle and they are moving on Nashville!” Then came a thought of self—an apprehension—a strong sense of personal peril, such as in another we call fear. He stepped quickly into the shadow of a tree. And still the silent battalions moved slowly forward in the haze. The chill of a sudden breeze upon the back of his neck drew his attention to the quarter whence it came, and turning to the east he saw a faint gray light along the horizon—the first sign of returning day. This increased his apprehension. “I must get away from here,” he thought, “or I shall be discovered and taken.”