Cumberland Gap, and Battery D, Independent Pennsylvania Volunteer Artillery, at Covington, Ky.

December 1, headquarters of the corps were stationed at Knoxville, East Tennessee The troops were in the rifle-pits around the city, closely besieged by the enemy.

December 4, re-enforcements arrive for us from Chattanooga.

December 5, the enemy were compelled to raise the siege. They moved in the direction of Rutledge, East Tennessee, a distance of 35 miles from Knoxville.

December 7, the corps started in pursuit of the enemy, except Battery E, Second U. S. Artillery, whose guns are too heavy to transport over the bad roads that are in this action of the country.

December 9, the corps arrived at Rutledge.

December 13, the Third Brigade, First Division, was ordered to Farley's Mills, about 7 1/2 miles northeast of Rutledge, on the Holston River. The enemy commenced to shell them from the opposite side of the river, when they were ordered to fall back to within 3 miles of Rutledge.

December 14, the First Division fell back to Blain's Cross-Roads.

December 15, the Second Division fell back toward Blain's

Cross-Roads.

December 16, 12 m., the Second Division halted within 2 miles of Blain's Cross-Roads, formed line of battle, and remained in that position during the afternoon, our cavalry skirmishing with the enemy half a mile in advance of our line during the whole afternoon.

December 17, the cavalry was withdrawn from our front, the enemy's sharpshooters following them up to our infantry line, when slight skirmishing commenced, without any loss.

December 18, drove back the enemy 4 miles, and posted our infantry pickets and established the troops in camp.

December 22, the enemy, under cover of the night, retreated to the south side of Holston River.

December 31, the headquarters of the corps and troops are encamped near Blain's Cross-Roads, East Tennessee, a distance of 18 miles from Knoxville. Battery D, Independent Pennsylvania Volunteer Artillery, and Third Brigade, Second Division, still remain on detached service, the first at Covington, Ky., and the latter at Cumberland Gap.

No. 12.

Report of Lieutenant Samuel N. Benjamin, Second U. S. Artillery, Chief of Artillery.

WEST POINT, December 20,[1863.]

Major-General BURNSIDE, U. S. Army:

DEAR GENERAL: Inclosed you will find an account of the siege of Fort Sanders, giving the plan of the defense and a description of the assault. It is miserably written, but I had to hurry it, as I am very busy, and could hardly get time to write at all; so please excuse mistakes and all deficiencies. The whole affair lasted full three-quarters