This is a launch of the same general construction as the Thornycroft, although a higher rate of speed is attained by this type, and there are several important modifications. The fire-room, or stoke-hole, is completely separated or bulkheaded off from the boiler, except the front part, so that in case the boiler collapses or is pierced by a shot there is no danger of scalding the crew. The pilot-house is placed aft in the compartment occupied by the officers. There is no visible smoke-stack. Two ports are cut in the sides of the launch, one on each side, and the products of combustion may be carried through either or both. The ports are provided with valves, which are held open by the force of the blast, but which close immediately if struck by a wave. The helmsman can direct the smoke through either port, so that in approaching a vessel the one on the side next to her is closed and the smoke through the other port is partially masked by the side of the boat. When running in a seaway both these ports may be closed, and a temporary smoke-pipe is shipped in the usual place. These boats are provided with a rudder at each end, both rudders being operated by the wheel at the same time. The forward rudder may be drawn up into a well, if desired, or in case that it gets fouled it can easily be dropped overboard. These boats have attained in smooth water a speed of 22 knots an hour. The torpedo arrangements are similar to those of the Thornycroft. Above 18 knots there is no noticeable vibration of the frame. _The Herreshoff Torpedo-Boat._ [Illustration: Herreshoff Torpedo-Launch.]