HEADQUARTERS DISTRICT OF FLORIDA, Jacksonville, July 12, 1864.

Captain W. L. M. BURGER,
Assistant Adjutant-General:

CAPTAIN: In compliance with the order of the 10th instant, just received, I have ordered the Fourth Massachusetts Cavalry to embark for Hilton Head. They shall be sent forward as rapidly as transportation will permit. This deprives me of all the mounted men who have been doing duty in front of Jacksonville. There are no other mounted men in the district, except the Seventy-fifth Ohio Volunteers, which can put into the field at any one time not over 250 mounted men, and which is only force charged with the defense of Picolata and the country to the south of Saint Augustine and Picolata. The execution of your order will leave me with about 200 mounted men for the service at all points. As the rebels have a cavalry regiment in front of Jacksonville, I shall be obliged to take nearly all the mounted men for the duty here. How I shall guard Picolata and the east bank of the Saint John's I do not now see. A large number of families have settled there under our promise of protection. If we abandon them the rebels will commit among them the usual atrocities. The raising of a Florida battalion is impracticable just now; men refusing to enlist because they think that Florida is about to be evacuated. If the major-general commanding will send one of the new regiments of colored troops to Florida, I think it will have the happiest effect.

The movements of the rebels toward Trout Creek continue. Their camp-fires are seen daily; their vedettes are pushed forward to the bank of the river and withdrawn. Within a few days past they have reconnoitered Yellow Bluff, the mouth of Trout Creek, near the gun-boat, and have built a good lookout in the top of a tree overlooking the gun-boat Ottawa. I had already started on an expedition to reconnoiter up Trout Creek when your order met me. In a day or two, however, I shall try it with infantry and endeavor to drive the rebels from their new camp. I had expected to send two Wiard guns and caissons to Stono River, but find that, although the requisition was approved, they were not sent. They are still at Hilton Head.

Your obedient servant,

WM. BIRNEY,

Brigadier-General, Commanding.

FLAG-STEAMER PHILADELPHIA, Port Royal Harbor, S. C., July 13, 1864.

Major General J. G. FOSTER,

Commanding Dept. of the South, Headquarters Hilton Head:

SIR: It often occurs that contrabands and others, enlisted in the naval service, desire to be discharged here when their terms have expired-that is, they desire to remain ashore, which is your jurisdiction, and this can only be done by your permission. While declining, therefore, to interfere with your authority, permit me to observe that it seems very objectionable to permit a population to grow up here of persons from whom there is no guarantee that they may not in some way become useful to the enemy, it being their