AMONGST the various articles designed to save life on occasions of disaster to ships, perhaps one of the most natural was a seaman's bed or mattress, composed of buoyant materials. Since the space on shipboard for the stowage of anything that is not indispensable is necessarily very limited, and in trading ships may often be of considerable money value, it is evident that all rafts, life-buoys, and life- belts, labour under great disadvantage, in that they are of no use except for the one object which is their immediate function, and that they may, in the majority of cases, be kept through the whole period of a ship's existence without ever once having to be employed. Hence it only too commonly happens that the shipowner, ship- master, and seamen, all alike, prefer running the risk which does not appear imminent, to putting up with the inconvenience that is always present. The expense of providing such things is like- wise nearly always grudged.

To meet these objections, various articles of the necessary equipment of a ship have, from time to time, been pro- posed to be converted into floating bodies to serve as life-buoys, such as casks and water barrels, benches, chairs, and sofas, deck houses, skylights, &c., and, as above stated, seamen's mattresses or beds.

In consequence of so comparatively few fatal accidents happening to ships of war it has been principally with a view to their being employed in passenger and trading vessels that such things have been hitherto proposed. The great risk, how- ever, that will be incurred by ships of war, in future, of foundering rapidly with all on board from the probable general use of torpedoes and steam-rams, has led thoughtful naval men to meditate seriously on the subject, and to consider what means it may be possible to adopt to lessen the great amount of loss of life which may be apprehended as likely to take place on such occasions. Amongst others is Rear-Admiral A. P. RYDER, an officer who has ever been indefatigably zealous in promoting the welfare of the noble service to which he belongs, and on the efficiency and superiority of which the high position of this country must ever depend. On the next page of this Number of our Journal will be found a Paper by Admiral RYDER, read by him at the United Service Institution on this subject, containing an account of some experiments to test the buoyant properties of an ordinary ship's hammock when lashed up for stowage in the nettings, and suggesting that the Admiralty should cause further experiments to be made, including the trial of mattresses stuffed with different buoyant materials.

Recent experiments have proved that an ordinary sized cork hammock mattress, of the average weight of about 7i Ibs., after being immersed in fresh water for an hour and a half, has sufficient buoyancy to support above the surface a weight of more than 37 Ibs., which amount will support an average sized man with his head and entire shoulders above the water; and that after twenty-four hours' immersion, its buoyancy is not greatly diminished.

There can be no doubt, therefore, that such mattresses would afford invaluable aid to any persons in the water who were unable to swim, or even to the best of swimmers if heavily clad, or having to remain some time immersed before being rescued.

In a ship of war, hammock mattresses thus rendered buoyant would be especially suitable, since the hammocks, being stowed on the upper deck, would always be immediately at hand; and in the event of sudden accident to a ship, such as the explosion of a torpedo under her or her being run down by another vessel, there would be a hammock for each of the crew; and a few spare ones might be kept stowed in the nettings for the purpose of practising men in their use on suitable occasions, which would also then be available for the use of the officers of a ship on any such emergencies as those above referred to.

It would undoubtedly be necessary that a ship's crew should learn, by experimental trial, how to make the most of such aid, for, except in the case of a life-belt, which is securely attached round the body, a person may be drowned even with an amply buoyant article within his reach, from not knowing how to grasp it or how to use it advantageously. The most effectual mode of using such beds would be best ascertained by experiment, but we apprehend that it would be found to be by bending the hammock, as lashed up and stowed in the netting, and bringing the two ends together, thus forming a species of life-buoy, shaped somewhat like a horse-collar, which the person using it would pass over his head and under his arms, in which position it would closely encircle his body. The two ends of the hammock would, of course, be securely lashed together, which might be quickly done by the ordinary lanyards by which the hammock was hung up when slept in.

The best material for the hammock itself would also be matter for consideration, and we arc inclined to think one made of closely-woven cotton canvas would be both more buoyant and much more water-tight than the coarse hempen material commonly employed. The hammock lashings might also be of manilla rope, which is more buoyant than tarred hemp.

We believe that cork mattresses have already been adopted to a considerable extent in the Russian Imperial Navy; and we have reason to know that their addition in that of France was under consideration at the time when the late unfortunate war commenced between that country and Germany. Entirely agreeing with Admiral RYDER that they would be a valuable acquisition to our own Naval Service, and believing that they would prove as comfortable beds to sleep on as those of the ordinary horse-hair or wool or other unbuoyant material, we trust that the Lords of the Admiralty will cause experimental trial of them to be made.

On the occasion of the destruction of H.M.'s ship Bombay by fire, near Monte Video, in 1864, referred to by Admiral Ryder, when no less than 91 men and boys perished alongside the ship, if each of them had had a hammock with cork mattress within their reach, when forced by the flames to jump into the sea, possibly not a single life would have been lost.