HDQRS. NORTHERN DISTRICT, DEPT. OF THE SOUTH, Folly Island, S. C., July 28, 1864.

CAPTAIN: I have the honor to report that nothing of special interest has occurred in this command since the last visit of the major-general commanding. The firing upon Sumter has of the major-general commanding. The firing upon Sumter has been continued at the same rate as when General Foster was here, and with good effect. The enemy has only answered our fire by a few shells from Sullivan's Island or James Island. A reconnaissance around Sumter, made by Lieutenant Eaton, of the One hundred and twenty-seventh Regiment New York Volunteers, is reported to General Foster, in connection with the object of the same.

On the night of the 25th to the 26th instant, 4 deserters of the First South Carolina Artillery, from Fort Jonson, came into our lines across the marsh, and were picked up by the boat infantry. The information given by them is made by the subject of another report.

The engineer work on Morris Island has been carried on as rapidly as possible with the force at my disposal. Captain Edwards, of the First New York Volunteer Engineers, with 68 men, arrived here yesterday,and was assigned to the post of Morris Island.

The enemy on my front seems to have about the same force as before the late movements on John's and James Islands. They have been unusually active in fatigue duty around Johnson and Simkins and the works near Secessionville, both repairing their present works, connecting the batteries with rifle-pits,and erecting new batteries.

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

Brigadier-General, Commanding District.

Captain W. L. M. BURGER,

Assistant Adjutant-General.

HDQRS. NORTHERN DISTRICT, DEPT. OF THE SOUTH, Morris Island, S. C., August 3, 1864.

CAPTAIN: I have the honor to report that nothing of importance has occurred within this command since my last communication. The bombardment of Sumter has continued according to instructions from department headquarters, as far as the supply of ammunition and the condition of the guns in the batteries will allow. The result for the past eight days has been favorable, and gives more hope of an ultimate demolition of the fort than ever before. The supply of mortar powder in the district has entirely run out, and I have been obliged to borrow 100 barrels from the navy to keep up the mortar firing. The ordnance officer informs me that he made requisition for this powder ten days ago, but has heard nothing from it yet.

In compliance with orders received from the major-general commanding, with regard to the exchange of prisoners to be effected in Charleston Harbor this day, the fire from our batteries was suspended as soon as the rebel steamer was seen coming out of the harbor, ad resumed after she had returned.

Last night 2 persons in a boat coming out from Charleston were picked up by our picket-boats. They represented themselves as officers of the Third Ohio Volunteers, lately brought to Charleston and now escaped. They give their names as B. C. G. Reed, captain