maintained, varying somewhat with each stroke of the engine.

Water level in the boilers was indicated by try cocks. The safety valve was controlled by a counterbalanced lever. A jet of salt water was injected into the exhaust trunk to form a vacuum by condensation. An air pump transferred condensate and sea water into a tank from which it passed overboard. Only about a tenth of this water was returned to the boilers.

Montgéry stated also that only the lower or gun deck was to be armed. No bulwarks were on the spar deck, only iron stanchions to which were fastened a breastwork of wet cotton bales when the Steam Battery was in action.

The Battery was designed to carry 30 guns (32-pdr.), with 3 guns in each end and 12 on each side, but no guns in the wake of paddle wheel and machinery. Hatches to give air to the stokehold were located amidships. The Battery was to have been supplemented at the ends of each hull by a Columbiad “submarine gun” (100-pdr.), Fulton’s invention, but these were not fitted. Provision was to be made in the fireboxes for heating shot, and a force pump with a cylinder 33 inches in diameter was employed to throw a stream of cold water, about 60-80 gallons per minute, for a distance of about two hundred feet. This could be done only when the paddle wheel was not in operation. The paddle wheel was housed, the top fitted with stairs to the spar deck. The gun deck, over the race, was used in part for staterooms, of which the bulkheads were permanent. Hammocks for the complement of 500 men were to be slung on the rest of the gun deck. The ship drew 10 feet 4 inches, with the port sills about 5-1/2 feet above the loadline. Burning wood, the vessel could carry about 4 days’ supply of fuel; burning coal, she carried 12 days’ supply.

Montgéry said that the vessel would be vulnerable to bombshells and hot shot, and that furthermore she could be boarded. The displacement of the ship, at service draft, was 1,450 tons, a figure Montgéry obtained from a copy of the original plan given him by Noah Brown.

Figure 6.—French sketch, in Rigsarkivet, Copenhagen, of inboard profile and arrangement of Fulton’s Steam Battery, showing details of the Fulton engine, probably taken from one of his preliminary designs.

In 1935, Lieutenant Ralph R. Gurley, USN, attempted a reconstruction in sketches of the vessel published in his article “The U.S.S. Fulton the First” in the U.S. Naval Institute Proceedings.[15] This reconstruction was based on the Patent Office drawing prepared for Fulton, and published by Stuart and Bennett, and the foregoing French sources. The Patent Office drawing showed the engine was an inclined cylinder and Lt. Gurley shows this in his sketch; in his text (p. 323) he says, “The engine was an inclined, single-cylinder affair with a 4-foot base and a 5-foot stroke.” Gurley’s attempt to reconstruct the Steam Battery is the only one known to the author.

Copenhagen Plans

In 1960, Kjeld Rasmussen, naval architect of the Danish Greenland Company, was requested by the author to inspect in the Danish Royal Archives at Copenhagen a folio of American ship plans, the index of which had listed some Civil War river monitors. Mr. Rasmussen found the monitor plans had been withdrawn but discovered that three plans of Fulton’s Steam Battery existed, as well as plans of the first Princeton, a screw sloop-of-war.

Copies of the Steam Battery’s plans were obtained at Copenhagen in September 1960 through the courtesy of the archivist, and were found to consist of the lines, copied in 1817, an inboard profile and arrangement, and a sail and rigging plan. From these the reconstruction for a scale model was drawn and is presented here with reproductions of the original drawings upon which the reconstruction is based.

It is apparent that Montgéry’s description is generally accurate. The vessel is a catamaran, made of two hulls, double-ended and exactly alike. The outboard sides are “moulded,” with round bilges, the inboard sides are straight and flat, as though a hull had been split along the middle line and then planked up flat where split. The hulls are separated by the race, in which the paddle wheel is placed at mid-length. The topsides are made elliptical at the ends, and the midsection shows a marked tumble-home over the thick topside planking but less on the moulded lines.