night a trestle bridge was built by the Engineer Corps, under Major Houston, of the Engineers, about 800 yards above the railroad bridge, in a bend of the river which swept the farther hill, the banks here being covered with woods. This gave us another and a shorter and hidden line of communication, and enabled Hartsuff's whole brigade and Thompson's and Matthews' batteries to be thrown over to occupy these heights. The firing to-day was very animated between the enemy's batteries and our own.

Since the morning of the 21st the enemy's heavy columns of infantry, artillery, and trains could sometimes be plainly seen passing up to our right, and their course, when behind the woods, was indicated by the lines of dust ascending above the trees. The attack on my front had been followed up by similar ones on the position held by the other corps above and below me. All the movements of the enemy gave assurances he was moving to turn our right, having failed on the front and left. This was confirmed by the intelligence that he had crossed at Sulphur Springs and was moving on Warrenton.

On the night of the 22nd, just as I received your orders for the Third Corps to cross at the bridge, and in connection with the commands of Reno and Reynolds below me, to fall on the rear of that long column which had been passing before us for two days up the south side of the river, an officer came to report to me, in your presence, that the rain which had been falling during the night had so swollen the river that the trestle bridge had been swept away and had lodged against the railroad bridge, the center of which was yielding to the pressure of the flood, and was in imminent danger of being carried off. The river had risen some 6 feet, and all the fords were gone.

Fearing for the safety of Hartsuff's brigade, who were on the opposite bank, I ordered them to be withdrawn. It was now impracticable to cross the river and make the attack you had planned. Your orders then were to move the army against the enemy, who had crossed at Sulphur and gone to Warrenton, whence he had made the attack with his cavalry at Catlett's, and who, it was thought, would be unable, on account of the state of the river, either to recross or be re-enforced.

The withdrawal of Hartsuff's brigade from the south side encouraged the enemy to move forward to seize the hills he had abandoned before we could complete the entire destruction of the railroad bridge, which we did not wish to leave for the enemy to repair and us to annoy us on our march to Warrenton. They opened a furious fire upon us, and, moving their infantry down in masses, rushed upon the hill Hartsuff had just left. Matthews', Thompson's, and Leppien's batteries, and our sharpshooters returned their fire so vigorously that they were soon driven off. Leppien's especially did them much damage. Farther to the right Hall's battery engaged two of the enemy's batteries and drove both of them and dispersed a regiment of infantry. The firing of this excellent battery was, us usual, rapid and accurate. Farther up the river the batteries of Reynolds and Naylor were also successfully engaged. In the mean time the corps, agreeably to your orders, was on the march to Warrenton, to be on the right of General Sigel, who was to attack the enemy, and who was to have Generals Reno and Banks on his left and rear, General Reno having moved up the river for this purpose. Reynolds' division, following him rejoined the Third Corps, and marched after the division of Generals King and Ricketts' to Warrenton. The rear guard of the corps was commanded by Brigadier-General Tower, who had his brigade and the batteries of artillery holding