observation and a man-hole that served as means of ingress and egress for the crew. For propulsion, Fulton proposed a screw as Bushnell had already done, a principle that was not to be adopted in general practice until nearly half a century later in spite of its many and great advantages over side wheels. The screw was placed at the stern and directly ahead of the rudder and was operated by a hand crank and gearing turning a shaft passing through a stuffing box. The crank was to be turned by man power only. Plunging was to be secured by pumping water into the keel, while submersion at a given depth, provided the boat was in motion, was to be attempted by means of two inclined planes attached to the sides of the steering rudder. The angle of these planes could be altered from within, thus giving an upward or downward direction to the boat. Motion on the surface he thought to obtain by a fan-shaped sail which, with the supporting mast, could be folded down to the deck and then, preparatory to submersion, covered with envelopes like the wings of a fly. Fulton estimated that he could work the boat with a crew of three men. [Illustration: FULTON’S “NAUTILUS,” 1798 ] The offensive feature of the design consisted first of a vertical spike attached to the top of the observer’s dome. In the spike was an eye through which passed a cord leading through a stuffing box to a winding spool in the forward end of the boat. The second part was a torpedo attached to the other end of the cord. In action the Nautilus would be placed directly beneath the hull of an enemy vessel, the spike being in contact with the bottom planking. As one end of the spike projected into the observer’s dome, a blow on that end would drive the upper end, which was sharp and detachable, into the ship’s timbers. Then the Nautilus was to move forward leaving the spike sticking in the ship. As she moved forward, the torpedo would trail behind, but as the cord passed through the eye in the spike, the torpedo would soon be brought into contact with the hull, when the shock would fire the discharge. In the meanwhile, enough cord would have been paid out to permit the Nautilus to have attained a safe distance. The Commission to whom the design was submitted found in its favor, except as to the sail arrangement, which they pointed out had the larger part of its area too far aloft, and that consequently the boat would lack stability under a strong wind. A translation of the Commission’s conclusion is as follows: