The number of horses required is eighty; for quality and description see page 46, Artillery Tactic. A few good saddle-horses for officers should be sent in addition, say eight or ten.

HENRY J. HUNT,

Brevet Major, Captain Second Artillery,

Commanding Light Battery M.

Steamer ATLANTIC,

At Sea, April 10, 1861.

HEADQUARTERS U. S. TRANSPORT SHIP ATLANTIC,
April 11, 1861.

Captain E. B. HUNT, U. S. Engineers, Fort Taylor:

SIR: You will make a reconnaissance of the island of Key West with a view to the erection of any field-works which may be required to enable the garrison of Fort Taylor and of the town of Key West to prevent a hostile landing. In making this project you will consult with the commander of the forces in the island, and call upon him for any necessary assistance. The project, when complete, should be submitted to headquarters of the Department of Florida for further orders. You will, for fear of accident, make it in duplicate, retaining one copy and forwarding the other to said headquarters.

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

HARVEY BROWN,

Colonel, Commanding.

U. S. TRANSPORT SHIP ATLANTIC,

April 11, 1861.

Bvt. Major L. G. ARNOLD, Commanding Fort Jefferson:

SIR: You will take measures for the occupation by sea-coast earthen batteries of all the points in the harbor of Tortugas necessary to secure a complete command of the anchorage and of the channels of entrance thereto. For this purpose you will consider that a certain number of sailing vessels of the Navy will be available. They will be moored in such positions as to command the anchorage and the passes, and will themselves be supported by the shore batteries. These batteries should be constructed to resist projectiles now used in our own and European navies, and should therefore be provided with earthen parapets of not less than twenty-four feet in thickness. It is considered that no battery should contain less than three pieces of heavy caliber, and that the means disposable will not permit more than three to be constructed at any one point. The batteries should be closed works capable of offering some resistance to a sudden assault; should contain bomb-proof magazines for a small supply of ammunition, renewable from the ships or from Fort Jefferson, and will be occupied by detachments from the crew, of the troops or the garrison of the fort, relieved at short intervals.

Sufficient shelter for the garrison must be provided. For this purpose temporary sheds of lumber will suffice. The guns should be mounted in barbette. They will be supplied either by the fleet or by the Ordnance Department. The works will be constructed of the materials to be found on the spot, sand and fascines or gabions. Timber will be supplied from the public stores for the platforms, magazines, &c.

The points to which your attentions particularly directed as probable to be occupied are Bird Key, Sand Key, Loggerhead Key, East Key,