Plan of Lungleys Unsinkable Ship, 1861. Diagram showing the engine room and coal store. A A are the parts in which, if the bottom of the vessel is torn out, the water will take the place of ballast, the ship being as safe as before... The Briton is...the first vessel built on the newly patented principle of Mr. Charles Lungley, of Deptford, for the construction of unsinkable and incombustible ships...The great advantage which is obtained by the invention is the localisation of injury and facility of remedy, wherever injury may be inflicted. The principle is simply to divide each deck from the other by a watertight flooring of iron, so that...each [deck] becomes a distinct hull of itself, unaffected by any injury which may happen to either of the others, and by the equalisation of the weight of water which may have obtained egress, keeping the vessel in a level position, or what is technically called "an even keel...the engine room is completely isolated...being inclosed as it were in four solid walls of iron, excepting, of course, the communication with the flush-deck, so that unless the ship sunk bodily down underneath the water it would be impossible for it to penetrate to the fires, or in any way interfere with the working of the screw. From "Illustrated London News", 1861.