FORT MONROE, VA., March 28, 1862.

Honorable E. M. STANTON:

A large number of soldiers arrived to-day-it is said 12,000-including several regiments of regulars. i have no official returns of the number. The rebels fired from Sewell's Point a ball that fell among our shipping, within a quarter of a mile of the shore, opposite Camp Hampton.

JOHN E. WOOL,

Major-General.

CHERRYSTONE, VA., March 28, 1862.

Honorable E. M. STANTON,

Secretary of War:

Yesterday afternoon I visited the Vanderbilt, and found her preparations are far advanced and that she is at any moment ready for action Her steam is kept constantly up. there are seven steamers here, all ready to act as rams, with more or less efficiency, but by their combined operations abundantly able to destroy the Merrimac. In my judgment it is impossible for the Merrimac to come down to Fort Monroe without being sunk by the steams rams. She can run up James River; she can attack Newport News, and do what she pleases above Fort Monroe, as the channel above is too narrow and crooked to admit of the steam rams being worked against her with effect; but while remaining up there out of our reach she can do us no harm. Commodore Goldsborough is fully awake to the importance of destroying the Merrimac, and has a clear comprehension of the manner in which that can best be done with the means at his command. I think he will do his duty both skillfully and bravely, and I have no doubt with success. Mr. Vanderbilt fully approves Commodore Goldsborough's plan of battle, and desires the steamer vanderbilt to remain under Goldsborough's command. I have directed her so to remain until otherwise ordered by you. The large huns are not made as available as they ought to be. The 15-inch gun is not yet ready to be used with any efficiency, although it is mounted upon a carriage. It is important to have the great gun made available immediately for defense against the Merrimac. If you approve I will return this afternoon to aid in making it ready. The officers of two steamers of the French navy, now here, went to Norfolk yesterday under a flag of truce sent by Commodore Goldsborough. On their return this morning they at once got up steam in both ships, although they have had their fires out for the last week. This looks as if they anticipate a naval engagement to come off soon. This is all the information I can gather as to the force and disposition of the rebels. I think they will make no fight this side of Richmond. Our chief difficulty will be to land transportation. I will await your answer here.

P. H. WATSON,

Assistant Secretary of War.

SPECIAL ORDERS, HEADQUARTERS ARMY OF THE POTOMAC,

Numbers 94. Near Alexandria Seminary, Va., March 28, 1862.

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III. Brigadier General J. P. Hatch is relieved from duty with the First Army Corps (McDowell's), and will, without delay, report to Major General N. P. Banks for the command of the cavalry serving with the Fifth Corps.