Numbers 83.] FORT SUMTER, S. C., March 25, 1861.

(Received A. G. O., March 28.)

Colonel L. THOMAS, Adjutant-General U. S. A.:

COLONEL: I have the honor to report that everything is quiet around us, and that we do not see any work being prosecuted except that at the new battery at Fort Jackson. They are practicing this morning with shells from the columbiads at Fort Moultrie and from a mortar battery between Nos. 9 and 10.

I inclose herewith a report of the condition of our fort. It will be seen that a great deal of work has been done since we came in. We are now about finishing the closing of the openings in the gorge-a measure first suggested by Captain Doubleday.

I have not noted the different operations we have been engaged in from time to time, as I did not deem them of sufficient importance to require it.

I am, colonel, very respectfully, your obedient servant,

ROBERT ANDERSON,

Major, First Artillery, Commanding.

[Inclosure.]

FORT SUMTER, S. C., March 24, 1861.

Major ROBERT ANDERSON, First Artillery, Commanding:

SIR: In accordance with verbal instructions given by you, we have the honor to submit the following report upon the condition of Fort Sumter when occupied December 26, 1860, the measures taken to put it in a state of defense, and its present condition:

Condition of the work December 26, 1860.

The barbette tier was ready for its armament: Three 24-pounders were mounted at the left and three more were ready to be mounted at the right gorge angle.

NOMENCLATURE.

*MAP.

The second tier of arches was not ready for its guns. The embrasures were not yet placed, and forty-one openings, eight feet square, were left in the scarp wall for this purpose. Those on the flanks (20) were closed only with a sheathing of 1-inch boards; the remainder, on the faces (21), were either entire open or closed with three courses of brick dry-laid,