Capt. Fox, who visited Fort Sumter on the requisition of the War Department, has returned here and reported the result of his mission. It is very well understood that he had a plan for introducing reenforcements, which had been submitted to the members of the Cabinet, and was regarded as measurably practicable but attended with the probability if not certainty of collision, which constituted the chief objection to its adoption. He is perfectly familiar with all the approaches to the harbor of Charleston, having been long connected with the coast survey, and had practical experience as the commander of one of Aspinwall's steamers. His scheme did not contemplate any serious danger in running the gauntlet of the batteries on the islands which guard the channels, but only in landing the men and provisions at Sumter, after it had been reached. If a fire was opened on his transports from Fort Moultrie or the other batteries, it would be necessary for Sumter to silence them in order to discharge the reenforcements. Any attempt, therefore, looking to that object would almost inevitably lead to bloodshed, and before resorting to it, the Administration would be constrained to expect that alternative. Even if successful without great loss of life, nothing would be gained but the retention of a fortress which has only a local value in protecting Charleston, and is of no national moment whatever.
Capt. Fox is fully impressed with the courage, integrity and sincerity of Major Anderson, with whom, however, his communication was necessarily limited, as Gov. Pickens sent Capt. Hartstein, late of our Navy, as an escort with him to the Fort, who kept within earshot during most of the interview, or, at least, near enough to prevent any free communication. He considers that the Fort can be reenforced either by a military operation, which, of course, would require a force not at the disposal of the President, or by the strategy already referred to, with its attendant hazards of a desperate conflict. The supply of provisions now in the garrison will probably enable Major Anderson to sustain his command reasonably well until the 15th of April. From all the facts disclosed by this investigation, it is manifest that Fort Sumter must be abandoned, or civil war inaugurated. Capt. Fox is cautious, intelligent and well-informed, and was brought to the notice of the Government by Mr. Aspinwall and some of the principal ship-owners of New-York and Boston.