The submarine boat is wholly constucted of boiler iron, connected by rivets. In shape it is an elongated ellipse, resembling somewhat the form of an egg; in length it is thirty feet, and ten feet in diameter at its greatest tranverse section; it has thirty-six tons of displacement, and weighs 20,000 lbs. At its sides are placed thirty orifices-twenty six of these, which are eight inches in diameter, are filled with bull's-eyes, as is the custom in ships, for the purpose of admitting the solar light into the interior. Of the four remaining orifices, two are used as entrances for men into the vessel; and the two others at the bottom of the vessel communicate directly with the soil at the bottom of the waves. These last two orifices, which we will call hatchways, are each two feet and a half in length by eighteen or twenty inches in breadth. At the stern of this novel vessel, on its exterior, just above the rudder, is seen a screw propeller, about three feet in diameter, which is sufficient to propel the vessel without difficulty. Both the propeller and the rudder have shafts communicating with the interior, passing through stuffing boxes. The men in the interior of the vessel can thus guide its motions with facility. On the sides, and at the exterior of the boat, are placed, upon hinges, two safety ballast supporters, and suspended by strong chains. These safety ballast supporters, which are constructed of wrought iron, resemble in shape a gridiron, and their object is to carry, when desired, a quantity of stone ballast of no value, which loads or lightens the vessels at pleasure in its ascending or descending movements. The movements of these safety ballast supporters are also governed by apparatus in the interior of the vessel. A stout iron bolt, which passes through a stuffing box, and which may be moved up or down in it, raises or depresses the safety ballast supporters as is desired. If we enter the interior of the submarine boat through the man-hole, we find ourselves in an apartment which in extent occupies about two-fifths of the vessel; the other three-fifths of its volume being occupied by two large reservoirs, to which are fitted two pairs of pumps, each having two separate functions, either for air or for water. The object of having two pumps for each of these uses, is to guard against those accidents by which one of them might be rendered unserviceable. This precaution is the more necessary as the pumps are employed in every movement of the submarine boat. Each of these pumps, No. 1 and No. 2, is provided with four cocks, whose use is to produce alternately the expansion and compression of the air, and the expulsion or supply of water in such a manner that they may throw off, or compress, or supply air or water at pleasure, to the reservoirs to which we have already referred; for the whole operation of the submarine boat depends upon the displacement of a certain quantity of condensed air, and in taking in or throwing off a body of water more or less considerable, by working the pumps. Thus, if it is desired to descend to the bottom of the water, the crew, before closing the man-hole by which they entered, will employ themselves in forcing into the reservoir the supply of atmospheric air necessary to balance the weight of the column of water, proportioned to the depth to which it is desired to descend. For the lower it is desired to descend, the more should the air be condensed in the reservoir, so that its resistance may prevent the entrance of the water. Then, having thus obtained a sufficient supply of air, the manhole is to be closed, and we proceed to effect the entire submersion of the boat. This operation is in itself very simple. It will be easily understood, when we say that the men who are inclosed in the interior proceed with the water-pumps, to force into the water chamber, a sufficient quantity of water to overcome the equilibrium which keeps the boat floating, and to sink it to the bottom of the stream. Then the boat, by virtue of the law of heavy bodies which only possess the requisite weight to overcome the equilibrium of the pressure and of the specific gravity of water, passes through the liquid at the velocity of one foot a second, and settles gently upon the bottom. After arriving at the bottom, the crew proceed to produce the balance of the atmospheric pressure with the pressure of the water in which they are placed, by means of a small valve which is between the two hatchways at the bottom, and of another valve which is placed behind the pumps, the last of which communicates with the air-chamber. Let us suppose the valve No. 6 alone to be open; the pressure of the water of the river will immediately cause a jet d'eau in the cabin: but if, to prevent the invasion of this water, the valve 8 be opened at the same time, a portion of the condensed air in the reservoir, rushing into the cabin, will there establish a resisting pressure, capable of overcoming the power of the pressure of the water, and from that moment the water of the river will be excluded by the resistance of the pressure of the atmosphere of the interior, and the equilibrium of pressure and resistance will be permanently established. The hatchways are then to be opened, and the submarine soil will be exposed to the view and touch of the workmen within, who may anchor upon it, and operate with equal facility, either for mining rocks, or for fishing gold, pearls, &c., &c. The mode of reascending is also perfectly simple, and as easily understood as that of descending, and may be performed in about the same time; thus, if it has been necessary, for example to take in the weight of a thousand gallons of water, to sink the boat to the bottom of the stream, it will be only necessary to expel the same weight of water, with the same pumps, which act in a double capacity, to lighten it sufficiently to cause it to rise to the surface; or, if it is desired to ascend more suddenly, it will be sufficient to work the bolt to which are attached the chains by which the safety ballast supporters are suspended with the external ballast contained on them; at the same instant, the boat, freed from a weight double that of the water which has retained it at the bottom of the stream, darts to the surface with the speed of ten feet a second. Purity of the air breathed by the men in the boat. This fluid, which, by the known effect of breathing, becomes more and more charged with carbonic acid gas, whose deleterious effect upon the lungs is well understood, is purified by means of a pump, which, taking it from the cabin, passes it through a solution of patash, which is kept in a caustic state by means of quicklime, in which it deposits its carbonic acid, and returns to the men only pure oxygen. The submarine boat can safely descend to navigate, or remain stationary under the water, at the depth of from ten to one hundred feet, with or without a direct or indirect communication with the exterior. The crew consists of from three to six men, who can remain, without inconvenience, from four to seven hours under water without ascending, or ascend at their pleasure. The air which they breath, is purified by a pump, which absorbs the carbonic acid, and gives out the oxygen in a condition favorable for the lungs. The pressure of the wholesome air in the cabin, not being above two and one-half atmospheres for one hundred feet of depth, is supportable seven or eight hours without fatigue. The boat may be conveniently employed to explore the bottoms of rivers, lakes, and harbors, either to examine reefs, or to mine them with a view to their removal. It may also be employed in submarine fisheries for pearls, for examining sunken vessels, mining for gold, &c. It may also be used very advantageously in laying wire for telegraphs, and in the salvage of sunken vessels. For these operations, it may accomodate a crew of seven men. The construction of a Submarine Vessel will cost about 5,700 or 6,000 dollars, and for extraordinary occasions, may be constructed upon a larger scale. This apparatus may in time be rendered the means of effecting great services to the navy department, for exploring the bottom of ports, inspecting docks, securing dams, inspecting the foundations of bridges, building up submarine constructions, carrying cements and materials to the bottom of basins, looking for breakers, studying the coasts, making submarine maps, ascertaining currents, looking for wrecked persons, &c. It is intended for gold and commercial marine searching; also for fishing for pearls, mother of pearls, coral, sponges; recovering property in sunken ships, blasting rocks, putting at the bottom of rivers and preserving from any accidents, the wires of magnetic telegraphs, &c., &c. |