The Air-Lock Principle Applied to the Battleship
���Foiling the Torpedo with an Armor of Air
��The broken-away section at the left shows how the compartments in the way of the boiler-room would be filled with compressed air were the vessel hit amidships. Similarly, the section at the right shows how the compartments would be filled if the boat were hit near the bow. At the left it is noticed that the intact compartment nearest the damaged area is filled with
��compressed air at a pressure of fourteen pounds to the square inch. Adjacent compartments are filled with air at the lesser pressures of nine and four pounds, ac- cording to the distance from the punctured section. A ship thus injured could proceed to port under its own steam. The air locks permit men to descend into the injured compartment to make temporary repairs.