FORT SUMTER, July 21, 1864.

CAPTAIN: I reported my arrival yesterday evening by telegraph. I regret to say that on my arrival I found Captain J. C. Mitchel, First South Carolina Artillery, was dead from the wounded he had received during the day. Captain Philips, Thirty-second Georgia, the temporary, commander, turned over the fort to me, and, after as careful inspection as could be made at night, I found the fort not seriously damaged by the present bombardment. Captain John Johnson, engineer in charge, is endeavoring to repair during the night whatever damage may be made during the day; every effort will be made to effect this purpose. The fire from rifle guns lately been directed upon the southwest angle with considerable effect, cutting away the exterior crest, and thus making a more easy ascent with the debris which falls. The loss of material at this point has required the abandonment of the most southerly casemate on the second tier of the western face, and if it continues will require a similar abandonment of the corresponding casemate in the lowest tier; these casemates are being filled up, and the only real loss will be the loss of quarters. The enemy are using some incendiary shell upon this point, and I have been compelled to remove the ammunition from the southwest magazine for fear that some incendiary matter may be communicated by the ventilator, which cannot be filled up at present. The firing upon the gorge wall has been discontinued, and I hope that it will soon be repaired. The boom has been broken in two places near the southeast angle, and I would earnestly urge upon you the necessity of having it repaired at the earliest possible moment. Captain Johnson thinks it necessary that about a thousand bags of sand should be sent down very night whenever it can possibly be done, as if the present bombardment continues it will be required in large quantity. He desires it to be sent in bags, as it is easier handled. In the event of an attempt to assault the fort it will be important that the batteries on Sullivan's and James Islands be apprised as soon as possible, and therefore I desire to keep a signal officer on the parapet hall night, so that he may be able to communicate the intelligence of the enemy's approach as soon as it is known to ourselves. I have only 2 signalmen here at present on duty and I cannot carry out my wishes in the above respect unless the number is increased. I would therefore respectfully request that the signal force be increased to 4. The garrison appears to be in good spirits.

Very respectfully, your obedient servant,

T. A. HUGUENIN,

Captain, Commanding.

Captain W. F. NANCE,

Assistant Adjutant-General.

FORT SUMTER, July 21, 1864 - 10.30 p. m.

Two hundred and thirty-six mortar shells (37 missed), 93 Parrott shells (11 missed) fired at fort to-day. No one hurt since last report.

HUGUENIN,

Captain.

Captain NANCE,

Assistant Adjutant-General.