The ferry-boat to be a broad flat-bottomed punt, A, at the bottom is a pulley-shaped wheel and axis, B, about a yard in diameter, carrying a rope fastened to the two opposite sides of the lake, which will sink to admit the passing of other boats; this, wheel is put in motion by the correspondent one above it, which has five times as many teeth as the pinion c, consequently, at every five turns of the winch E, the wheel makes one revolution, and the boat advances three yards, or three times the diameter of the wheel; at each end of the boat the rope must pass through rings of brass, smoothly polished, which will always guide it to one certain spot. The whole machinery, which is very simple, and not likely to be out of order, may be covered by a box C c, to form a convenient seat in the centre of the ferry-boat, and the surface or deck of this boat D may be covered with gravel and cement, having a hand-rail on each side; thus it will in a manner become a movable part of the gravel walk.
