in addition other advantages which will be enumerated in the following description.

As stated above, the torpedo is self-propelling, the necessary energy being stored up in liquefied carbonic acid contained in a cylindrical vessel, E, carried by the torpedo. The vessel, E, communicates, by means of a small bent pipe extending nearly to its bottom, with a small chamber, B, the passage of the liquid being controlled by means of the cock or tap, F. The chamber, B, is in communication, by means of a small aperture, with the nozzle, G, of an injector, T, constructed on the ordinary principles. The liquid as it passes into the chamber, B, volatilizes, and the gas passes through the nozzle of the injector, which is surrounded by water in direct communication with the sea by means of the opening, W. The gas imparts its energy in the well-known manner to the water, being itself entirely or partially condensed, the water thus charged with carbonic acid gas being forced through the combining cone of the injector at a very high speed and pressure. Preferably the water is here divided into two streams, each driving a separate rotary motor or turbine, H, themselves driving twin screws or propellers, I. The motors exhaust into the hollow shafts, J, of the propellers, which are extended some distance beyond the propellers, so that the remaining energy of the water may be utilized to aid in propelling the torpedo on the well known principle of jet propulsion. The torpedo is preferably steered by means of the twin screws. A disk or other valve, A, is pivoted in an aperture in a diaphragm dividing the outlet of the injector, and is operated by means hereafter described, so as to diminish the stream of water on one side and increase it on the other, so that one motor, and consequently the corresponding propeller, is driven at a higher speed than the other, and so steers the torpedo.

PAULSON'S SELF PROPELLING AND STEERING TORPEDO.

The valve, A, is operated automatically by the following arrangement: A mariner's compass, P, placed in the head of the torpedo has its needle connected to one pole of a powerful battery, D. A dial of non-magnetic material marked with the points of the compass is capable of being rotated by the connections shown. This dial carries two insulated studs, p, each electrically connected with one terminal of the coils of an electromagnet, K, whose other terminal is connected to the other pole of the battery. These two magnets are arranged on opposite sides of an armature fixed on a lever operating the disk or valve, A. Before launching the torpedo the dial is set, so that when the torpedo is steering direct for the object to be struck, or other desired point, one end of the needle of the compass, P, is between the steeds, p, but contact with neither, the needle of course pointing to the magnetic north. Should the torpedo however deviate from this course, the needle makes contact with one or other of the studs according to the direction in which the deviation takes place, and completes the circuit through the corresponding electromagnet, which attracts the armature and causes the disk to move, so as to diminish the supply of water to one motor and increase it to the other, and so cause the torpedo to again assume the required direction. Supposing the object which it is intended that the torpedo should strike be a large mass of iron, such as an ironclad, the needle will be attracted, and, making the corresponding contact, will cause the torpedo to be steered directly away from the object. In order to prevent this, a second compass, Q, is mounted in the front of the torpedo, and when attracted by a mass of iron, it short-circuits the battery, D, and thus prevents the armature being attracted, and consequently the torpedo from deviating. This needle is also capable of slight movement in a vertical plane, so that when passing over or under a mass of iron it is attracted downward or upward, and completes a circuit by means of the stops, which operate so as to explode the charge. The charge can also be exploded in the ordinary manner, viz., by means of the firing pin, X, when the torpedo runs into any solid object.

The depth at which the torpedo travels below the surface of the water is regulated by means of a flexible diaphragm, M, secured in the outer casing and connected to a rod sliding freely in fixed bearings. A spiral or other spring, O, is compressed between a color on the rod and an adjustable fixed nut, by which the tension of the spring is regulated so that the pressure of water on the diaphragm, A, when the torpedo is at the desired depth just counterbalances the pressure of the spring, the diaphragm being then flush with the outer casing. The rod is connected by suitable levers to two horizontal fins, S, pivoted one on either side of the torpedo, so that they shall be in equilibrium. Should the torpedo sink too deep or rise too high, the diaphragm will be depressed or extended, and will operate on the lines so as to cause the torpedo to ascend or descend as the case may be.

In order to avoid the risk of a spent torpedo destroying a friendly vessel, a valve is arranged in any suitable part of the outer casing, and is weighted or loaded with a spring in such a manner that when under way the pressure of the water keeps the valve closed, but when it stops the valve opens and admits water to sink the torpedo.

In our description we have only given the main features of the invention, the inventor having mentioned to us, in confidence, several improvements designed to perfect the details of his invention, among which we may mention the steering arrangement and arrangements for attacking a vessel provided with what our contemporary, Engineering, not inaptly terms a "crinoline," i. e., a network for keeping off torpedoes. The transverse dimensions of our engravings have been considerably augmented for the sake of clearness.—Mech. World.

DUPUY DE LOME.

M. Dupuy De Lome died on the 1st Feb., 1885, at the age of 68. It may be questioned whether any constructor has ever rendered greater services to the navy of any country than those rendered by M. Dupuy to the French Navy during the thirty years 1840-70. Since the fall of the Empire his connection with the naval service has been terminated, but his professional and scientific standing has been fully maintained, and his energies have found scope in the conduct of the great and growing business of the Forges et Chantiers Company. In him France has undoubtedly lost her greatest naval architect.

The son of a naval officer, M. Dupuy was born in October, 1816, near L'Orient, and entered L'Ecole Polytechnique when nineteen years of age. In that famous establishment he received the thorough preliminary training which France has so long and wisely provided for those who are to become the designers of her war-ships. After finishing his professional education, he came to England about 1842, and made a thorough study of iron shipbuilding and steam navigation, in both of which we then held a long lead of France. His report, subsequently published under the title of "Memoire sur la Construction des Batiments en Fer"—Paris, 1844—is probably the best account given to the world of the state of iron shipbuilding forty years ago: and its perusal not merely enables one to gauge the progress since made, but to form an estimate of the great ability and clear style of the writer. We may assume that this visit to England, coming after the thorough education received in Francem did much toward forming the views to which expression was soon given in designs and reports on new types of war ships.