No. 186. Report of Captain Hiram Dryer, Fourth U. S. Infantry.

CAMP NEAR FALMOUTH, VA., December 19, 1862.

SIR: In obedience to instructions received from the headquarters First Brigade Regular Infantry, I have the honor to make the following report of the movements of the Fourth Regiment of Infantry during the seven days commencing on the 11th and ending on the 17th December, 1862:

In accordance with an order received, the regiment broke camp at 4 a.m. on the 11th instant, and proceeded, with the remainder of the brigade, to near the north bank of the Rappahannock, and formed line of battle my battalion, in which position it remained until 2 p.m. on the 13th instant, when it was ordered to cross the river at Fredericksburg. Having crossed, the regiment was then moved through the city, and ordered into position, about sundown, in the cemetery, at the south side of the city. Company B, First Lieutenant Abner R. Benedict being in command, was then thrown out as picket to the right of the pickets of the Third Infantry. At midnight the regiment was ordered to move about 300 yards to the left and front, taking a position, the right resting on a large tannery, and relieving some volunteers that had been posted there in the early part of the evening. As soon as the fog lifted, the next morning, the enemy's rifle-pits were discovered about 100 yards in front, and also that they were occupying some frame houses to the right about 75 yards, and on the opposite side of the road from the tannery, from which they kept a continuous fire upon the right of my regiment, as well as upon our line of pickets, which were lying down in an open field directly in their front. Upon discovering the position that Lieutenant Benedict was in with his company, I ordered him to fall back with his company to a ditch near the cemetery, and from thence to the cemetery itself, if possible. Previous to Lieutenant Benedict making the move, ha had lost 7 men wounded, and, while making it, he himself was wounded severely and 1 sergeant mortally. I then determined to occupy the tannery, (which was a good brick building), and after making loop-holes in the end, and posting a few good men at them as well as at the windows, succeeded in keeping the enemy's fire under until midnight, when we were relieved by a portion of Couch's division of volunteers. The regiment then moved into Fredericksburg, bivouacking for the remainder of the night, and remaining during all the next day and nigh, crossing the river early on the morning of the 16th instant with the brigade, and bivouacked on the old ground, on the north side of the Rappahannock, near Falmouth.

Our loss during the movement was 2 officers severely wounded, 2 sergeants and 2 privates killed, 2 musicians severely wounded, and 3 sergeants and 8 privates wounded.

The following are the names of the officers who were present with the regiment,viz: Captain J. W. Adams, Company K; First Lieutenant A. R. Benedict, Company B (severely wounded); First Lieutenant T. A. Martin, Company H; First Lieutenant A. Carolin, Company F; First Lieutenant W. S.

Collier, Company A; First Lieutenant I. F. Gensel, Company D (Severely wounded); Second Lieutenant G. M. Randall, Company C, acting adjutant; Second Lieutenant S. T. Crowley, Company F; Second Lieutenant G. Williams, Company I, and Second Lieutenant J. Simons, Company G.

Very respectfully, your obedient servant,

HIRAM DRYER,

Captain Fourth Infantry, Commanding Regiment.

Lieutenant WILLIAM H. POWELL,

Acting Assistant Adjutant-General.