I take particular pleasure in calling your attention to the management of the 8-inch mortar battery. It was under the charge of Lieutenant Prouty, who, as a volunteer officer of infantry, has had no practical experience in artillery practice and no knowledge on the subject except what he has gained since he reported to me. His success is the result of his own industry and energy. I inclose his report. I have since examined the fort, and find that of the 1,150 shots fired from our three batteries about 500 took effect within the works of the enemy, not counting the shells that were exploded over the fort. The fire of the Parrott guns was most destructive, these three pieces having disabled nineteen of the enemy's guns. Only about 3 feet in width along the tops of the scarp-wall of the western face could be reached by their fire, yet in this narrow portion 41 shots and taken effect, some of them penetrating the brick masonry to a depth of 2 feet. Comparing the angle at which the guns were fed with the angle of fall necessary for the shot to reach this wall, I am confident they could not have reached it without having been partially spent by passing through the crest of the glacis.

Barricades for the casemates have been formed within the fort by standing bars of railroad iron up against the casemate inside walls. Several traverse circles were blown up by mortar shell, but they did not seem in any other way to have disabled guns. Forty-eighth of the same shell exploded in the bottom of the ditch and a large number on the parade. One of the latter broke through into the drain of the fort.

The choice of the kind and caliber of the artillery used in the attack upon Fort Macon was certainly a good one. The object to be effected with the siege mortars was, at first, by exploding the shells at short distance above the fort, to drive the cannoneers from being efficiently served; afterward, by exploding the shells at or after striking, to disable guns. In both respects they were successful. The destructive and accurate fire of the 30-pounder Parrott guns has shown that the work of dismounting or disabling guns with them is not a matter of chance, but of certainty. There was no exposed wall on which to try their breaching power.

During the enemy's fire since the first commencement of operations I have often had occasion to observe the want of effect in the explosion of their shells. I have examined a few of those left in the fort and find them filled with cannon powder.

I have the honor to be, very respectfully, your obedient servant,

D. W. FLAGLER,

First Lieutenant of Ordnance.

Captain CHARLES T. GARDNER,

Assistant Adjutant-General.

No. 4. Report of Lieutenant Merrick F. Prouty, Twenty-fifth Massachusetts Infantry.

SIR: I have the honor to report that on Thursday, April 24, 1862, at 1 p.m.., I was ordered by you to move to the 8-inch mortar battery of four pieces, which was planted 1,280 yards from Fort Macon, and open fire on the fort.

Lieutenants Thomas and Kelsey and 15 men of the Third New York Artillery and 5 men of Captain Morris' battery were detailed to man