"To this end the improvements consist in the combination, in a torpedo or other submarine boat, of a cylindric body-section and a stern section which has its greatest bulk elevated or extended above the axial line of the body-section whereby the boat is effectually prevented from turning over. The boat may have a bow-section, which tapers to a point in line with the axis of the body-section. The improvements also consist in the combination, with such a boat, of a means for exhausting the steam, air, gas, or other motive agent employed to propel the boat, and for paying out a cable when the boat is used for a torpedo."