I remembered the misfortune of the discoverer Sindbad, whose ship, when he approached the magnetic mountain, fell to pieces, in consequence of the iron being all drawn out of it. To guard against a similar disaster, I fastened my vessel first with tree-nails, and then throughout with copper bolts firmly rivetted and clenched. To obviate the dangers of exposed and upright paddles, I built her with double top-sides for a space of thirty feet. Within this space the inner frames sloped in from the bends, on an angle of 45 degrees, and were covered and finished, in all respects, like the sides of a common ship. The outer work was carried up in the usual manner, so that the aperture was not apparent to external observation. Through this outer side a longitudinal port was cut, 30 feet long and 3 feet wide, for the paddles to play through obliquely, like the fins of a seal. The nave of the wheel was two feet within the sill of the port, between the double walls, and supported by both of them. The blades of the paddles, made of the best ash timber, and firmly coaked and rivetted together, were fitted into sockets in the nave; whence they could be easily unshipped for the purpose of closing the ports in bad weather, and rendering the vessel perfectly secure, with the paddles inboard. The shaft by which the power of steam was communicated to the paddles, passed through the inner side of the ship only, so that water could not be forced into the ship, even in the roughest weather, when the ports were closed. The inconvenience caused by the rolling of a vessel with upright wheels, was avoided by the obliquity of my paddles; the ship never rolling so much as to bring them to a perpendicular, or dip the nave to which they were fastened. To avoid accidents from fire, I built beneath and on the sides of the furnace and boiler of the engine, two narrow cisterns, perfectly tight, and of incombustible materials. These were kept constantly filled with the waste water of the engine, which was allowed to escape only by a spout at the top. No fire was permitted out of this enclosure. The economy of fuel, which was necessary from the length of the voyage, and from the emergencies which might happen, obliged me to adopt all the means of motion in my power. I therefore rigged my vessel as a ketch, with one large mast, and a long sliding topmast, which could be easily launched or sent up by the assistance of the engine; and a small mast abaft fitted to be struck at pleasure.