There will be an opening in this deck fore and aft eight feet wide fore and aft the boat for ventilation; a combing will be formed around this opening three inches above the deck and six inches thick; there will also be a center piece of the same height fore and aft the opening, over each beam athwartship piece will be fitted and fastened to the beam; the whole will then be covered with grating.

There will be awning stanchions fitted on this deck, one in each corner, to be well braced and about six on each side, to be eight feet high; also the same number in the center, to be ten feet high; the stanchions to be five and one-half inches square at the deck and four and one-half at the top; there will be an awning fitted to cover this deck.

There will be suitable cable bits at each end of the vessel for towing or securing the cables when at anchor, and chocks cased with iron for the cables to lay in when at anchor, and all the necessary fixtures; chain cables to have about five scuppers on each side, to be three by five inches when leaded.

To make a plain cabin with two state-rooms, two mess-rooms, and eight state-rooms for officers, fitted with berths and bureau and washstand in each room, to have a table for the cabin and each messr-room.

To build a suitable magazine, shell-room, and shot-locker as hereafter directed.

The port shutters will be made of two thicknesses of one and one- fourth oak plank, riveted together, to be made in two parts, hung above and below with suitable hinges and the necessary fixtures for lowering, raising, and securing them.

To have iron stanchions fitted all around the upper deck with an eye in the top two and one-half feet above the deck to reave the ridge rope.

To make and fit four pair of iron boats" cranes, fitted to swing and secured by chain guys; to make a wheel-house and fit the steering apparatus in the most approved plan, with wire or chain wheel ropes leading to the upper deck before the smokestacks; to furnish a suitable capstan, to be placed as hereafter directed.

To put in the shackles for breechings and necessary eyebolts for working the guns, &c.

The bottom decks and ceiling to be calked with oakum of the best quality, the seams to be paid with pitch, scraped, and painted with three coats of paint; the gun deck and all above to be planed, the bottom and sides will also be planed.

All to be done in a workmanlike manner, and to the satisfaction of the officers appointed by Government to inspect the work.

It is intended to protect the boiler and engines of this vessel with iron plates of sufficient thickness, and placed in a suitable position to protect them from injury from the effect of shot or shell, for which purpose seventy-five tons of iron plating have been estimated.

These gun-boats to be delivered at Cairo on or before the 20th September, 1861, completed, engines of board, ready for their armament, at the risk of the builders.

SPECIFICATIONS FOR ENGINES OF THE GUN-BOATS, Numbers 2.

(Drawing for boats made by Mr. Pook, naval constructor.)

Cylinders.- To be of cast-iron, one and one-half inches thick, with flanges one and three-fourths inches thick by three inches broad; to have a bore of twenty-two inches diameter, and of suitable length