coming forward to replace it, the enemy opened a very heavy fire of canister upon us from a masked battery of 12-pounders, about 150 yards off, on our flank. The column of caissons and the disabled piece were ordered to the rear, when the enemy's fire became so heavy, 1 man having been killed and 4 wounded in one section by the first discharge, that the cannoneers were directed to retire to cover. The men consequently fell back to shelter in the woods until a later hour in the day, when the enemy's attention being diverted by our infantry, firing was resumed with the two pieces before mentioned, and they were worked with good effect after night-fall.

I append a list of the casualties in the command.*

I have the honor to remain, sir, very respectfully, your obedient servant,

A. M. COOK,

Commanding Eighth Massachusetts Battery.

Captain ROBERT A. HUTCHINS,

Assistant Adjutant-General.

HEADQUARTERS EIGHTH MASSACHUSETTS BATTERY,
Mouth of Antietam Creek, Md., September 21, 1862.

SIR: I have the honor to submit the following report of the operations of the Eighth Massachusetts Battery in the action near Sharpsburg, September 17, 1862.

My command took up a position in the morning of that day on an eminence east of Antietam Creek, and the battery fired for and hour or more on two rebel batteries on the hills to the right and left of the village of Sharpsburg. After the object of this firing (the protection of our infantry in the passage of the bridge) was accomplished, the battery was ordered forward over the stream. While the command was halted in the road on the western bank of the creek, the enemy reopened a murderous fire of shot and shell into the ravine. The left section, under Lieutenant J. N. Coffin, was ordered forward to the heights on the right, and was therefore temporarily detached from the command. The right and center section, after remaining for some time under fire, necessarily inactive, proceeded up the road on the left of the stone bridge and opened fire from the heights above. Here they were subjected to a cross-fire from the enemy's batteries in front and on both flanks. After discharging several rounds they were compelled by the approach of darkness to suspend operations. The battery still continued, however, to hold the position, and remained upon the heights throughout the night and during the next day (the 18th) until about 5 o'clock p. m., when it returned to the eastern bank of the creek, having been relieved by other troops. For the operations of the left section, I beg to refer you to the report of its commanding officer, Lieutenant Coffin, which I inclose herewith. I desire to speak in terms of especial commendation of the conduct of Lieutenant John N. Coffin, whose gallantry on all occasions during the day was worthy of the highest praise.

I have the honor to remain, yours, very respectfully,

A. M. COOK,

Captain, Commanding Eighth Massachusetts Battery.

Captain ROBERT A. HUTCHINS,

Assistant Adjutant-General.