Another risk of the sea, which, because of long immunity from disaster, is in danger of being overlooked or underrated, is that of fire. The structural portions of a ship and its engine- and boiler-plant, being of metal, are proof against fire; but the stateroom partitions, the wooden floors and ceilings, the wainscoting, and the hundreds of tons of material used in decoration and general embellishment, to say nothing of the highly inflammable paint-work and varnish, constitute a mass of material, which, in the event of a serious fire, might turn the whole interior of a large passenger ship into one vast cauldron of flame. Fortunately, the bulkhead is as effective in confining a fire as it is in localising an inflow of water in the event of collision. Therefore, some of the bulkheads of the under-water portion of all passenger ships should be continued (of lighter construction) right through the decks reserved for passenger accommodations, to the topmost deck of the ship. But, perhaps, after all said and done, the greatest perils of high-speed ocean travel are to be found in that spirit of nautical _sangfroid_, or indifference to danger, which, as this disaster has proved, may in time begin to characterise the attitude even of so experienced a navigator as the late captain of the _Titanic_. Protection against the dangers of the sea may be sought in two directions: First, the enforcement of rules for more careful navigation; second, the embodiment of non-sinkable construction in the ship. The protection afforded by the one is limited by the fallibility of human nature. The protection afforded by the other is exact, absolutely sure, and will last as long as the ship itself. If we would make ocean travel safe we must make the ship, as far as possible, unsinkable. In other words, the naval architect must adopt that principle of construction, common in other lines of mechanical work, which has been aptly designated as "fool-proof." In the building of folly-proof ships, then (the term is here used in a modified sense and with not the least reflection upon that fine body of professional men whose duties lie on the bridge of our ocean liners), is to be found the one sure protection against the perils of the sea. We are well aware that the merchant ship, like the warship, is a compromise, and that the ingenuity of the naval architect is sorely taxed to meet the many demands for speed, coal capacity, freight capacity, and luxurious accommodations for passengers. All this is admitted. But the object of these chapters is to show that in designing the ship, the architect has given too little attention to the elements of safety--that, in the compromise, luxurious accommodations, let us say, have been favoured at the expense of certain protective structural arrangements, which might readily be introduced without any great addition to the cost of the ship, or any serious sacrifice of comfort or speed.