We had not been skirmishing more than an hour, before the army began to pour down the steep, rocky, dusty road. On they came, winding to and fro, down the serpentine road, now enveloped in clouds of fog, then emerging from the mist, their bright arms and brass trappings glittering in the sun; now submerged beneath a dense cloud of dust, they would again remain hidden for a time, till it was lifted off by a passing breeze, and again the mighty army, as if by magic, would stand out in full view before the beholder, martialing for the fray below. The rebels beheld them in terror, and they fled in confusion in the direction of Dug gap, leaving only a small cavalry force to skirmish with our advance. Gen. Negley then pushed a regiment or two out on the road, as far as Davis' cross roads, to feel the enemy, and ascertain his position. The reconnoissance was gallantly conducted--the rebels disputing every foot of the ground; and as soon as the reconnoitering party began to fall back, they hung upon its rear, until we gained our old position, at the foot of Lookout mountain. Early in the morning the General advanced with his whole division upon Dug gap, when the enemy's cavalry again disputed our progress, and the same ground was once more fought over, till we reached Davis' cross roads, at which place our army rested for an hour. The men being refreshed, pushed on again for the gap, where the rebels were found in overwhelming force. An engagement at once ensued, which lasted for several hours; but as the enemy was soon strongly re-enforced, Gen. Negley ordered a retreat, and his men were drawn off, slowly and quietly, one brigade at a time. Slowly the artillery was taken off the field, occasionally halting to throw a few shells into the advancing enemy, till finally we regained our old camp. Our loss in this skirmish was about forty killed, wounded and missing; but we lost nothing else; so leisurely were our forces withdrawn, that the teamsters stopped to reload a wagon which was upset. The 19th Illinois, and 18th Ohio Infantry, did noble work in this encounter, fighting at short range, and repelling two or three handsome charges. They killed thirty odd men, at a single volley, near the gap, all of whom were left on the ground by the enemy.