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 Montgery'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. [Illustration: Figure 6.] The lines plan agreed rather closely to Montgery's description of the hull. After careful fairing it was found the lines drawing would produce a vessel 153 feet 2 inches overall outside the stems, or about 151 feet over the planked rabbets, with a moulded beam of 56 feet and extreme beam of 58 feet. The moulded depth was 22 feet 9 inches and the width of the race was 14 feet 10 inches, plank to plank. The room and space of framing shown was 2 feet. The designed draft appears to be 13 feet and this would bring the port sills 5 feet 6 inches above the loadline and the underside of the gun-deck beams about 2 feet 9 inches above the loadline.