CHARLESTON, S. C., November 28, 1860.

Colonel R. E. DE RUSSY,

Commanding Corps of Engineers, U. S. A., Washington, D. C.:

COLONEL: I wrote your a few days since in relation to certain contingencies of defense which might occur before long int his harbor. I only wish to add now that if the War Department decides not to send more soldiers here, but to avail itself of the Engineer force to guard Forts Sumter and Pinckney, I shall require the assistance of anther Engineer officer. For several reasons my personal attention is required at Fort Moultrie just now. i require Mr. Snyder to give his personal attention to Fort Sumter, and such other matters as arise from time to time. In all probability it will soon become necessary to confine his duties more closely to Fort Sumter, and if I have to supply men to Castle Pinckney I shall want another Engineer officer to direct their labors and duties.

It is not certain that the emergency requiring the above division of the Engineer duties under my charge will arise, but it is better to be prepared, and I would respectfully urge you to grant my request, and, if so, that I may have the services of the officer detailed as soon as possible.

Very respectfully, your obedient servant,

J. G. FOSTER,

Corps of Engineers.

CHARLESTON, S. C., November 30, 1860.

Colonel R. E. DE RUSSY,

Commanding Corps of Engineers, U. S. A., Washington, D. C.:

COLONEL: I have the honor to acknowledge ether receipt of your letter of the 28th instant, and to request that the amount desired from the "Contingencies of fortifications" for the repairs of Castle Pinckney ($1,800), for one month, may be placed ot my credit with the assistant treasurer of the United States at Charleston, S. C.

I have entered upon the preliminary arrangements for commencing work, and on Monday, the 3rd of December, shall place in Castle pinckney the number of men authorized by the Department, with all the necessary arrangements for subsistence, lodging, &c., so that they may not leave the work until they are withdrawn.

Major Anderson, at my request, has kindly consented to detail an officer to assist me until en Engineer officer can be sent me for this purpose, for I regard it as necessary that an officer can be sent me for this purpose, for I regard it as necessary that an officer shall be constantly present at this work after the repairs are commenced. Lieutenant J. C. Davis is to be detailed, and is to report to me. I trust, however, that this temporary detail will no induce any delay in sending me another officer, as Major Anderson needs the services of all in his command. I shall endeavor to have the repairs promptly made, and to secure a proper protection to the property of the United States. In doing this it will be indispensable that I have the men instructed, to a certain extent, in the service, of the guns, and also in the manual of arm,s if I can arrange with Colonel Huger to have the requisite number of muskets sent from the arsenal. I shall also have Lieutenant G. W. Snyder take up his quarters in Fort Sumter, and give like instructions to about fifty picket men, in whom I can place reliance in case of an emergency.

I beg your o understand, however, that I do not regard all these arrangements as absolutely demanded by anything that now appears, but rather as a safe precaution in view of what may appear any day, if anything