Ferry, a passage by boat across water. Common rowing-boats are generally used for ferrying foot-passengers, but when horses and carriages have to be taken across, a flat-bottomed barge, with an inclined plane at one end, to rest upon the shore, for landing and embarking, is generally used. This may also be rowed across, but is usually drawn by a cable. The rope stretched across the river passes through rings or over pulleys attached to the barge, and the ferrymen move the barge across by pulling the rope. The rope restrains the barge from drifting in the direction of the stream. With a small boat this difficulty is obviated by the ferryman rowing obliquely, as though he were steering for a point higher up the river. Rafts are sometimes used for ferrying; and steam ferry-boats of various kinds and sizes are familiar to everybody.
Flying-bridge is the name given to a kind of ferry-boat which is moved across a river by the action of the combined forces of the stream, and the resistance of a long rope or chain made fast to a fixed buoy in the middle of the river. The boat thus attached is made to take an oblique position by means of the rudder; the stream then acting against the side tends to move it in a direction at right angles to its length, while the rope exerts a force in the direction towards the buoy. The course of the boat is analogous to the path of a rising kite. The holder of the kite corresponds to the buoy, the wind to the tidal stream, and the tail to the rudder. Flying-bridges may be used for military purposes. In the case of a wide river the rope or chain requires to be of considerable length, and must be supported by movable buoys or by small boats. Such flying-bridges are familiar to those who have sailed up the Rhine. In some cases, instead of an anchor laid in the stream, two shears or masts are erected, one on each bank, and firmly secured by guys. A stout hawser is then stretched tight from the top of one mast to the top of the other. There is a large iron ring or 'grummet,' to which is fastened one end of the boat rope, the other end being made fast to the boat or boats of which the bridge is composed.