391⁄2 inches in diameter by 18 inches stroke. There are two condensers, and the usual auxiliary engines for steering, electric light, distilling, air compressors, etc. There are six boilers of the Yarrow water-tube type, capable collectively of supplying steam for 4000 indicated horse-power. The weight of each of these boilers is 634 tons with water and fittings. The propellers are of manganese bronze, each with three blades, and are 7 feet in diameter by 8 feet pitch.

The armament comprises one 18-inch torpedo-tube, built into the stem for bow fire, and two 18-inch swivel torpedo-tubes on deck aft. The latter command both sides of the vessel. There will be a 14-pounder quick-firing gun mounted on the conning tower forward, three 6-pounder quick-firing guns on the deck aft, and two Maxim automatic guns just abaft the conning tower, one being on either side.

For feeding the boilers, the new system adopted by this firm has been fitted. There is in the engine-room a main feed pumping engine, which takes water from the hot-well and pumps it into a large cylindrical vessel at a pressure of 30 lbs. to the square inch. Across this vessel are stretched diaphragms of flannel through which all the water going to the boilers has to pass, in order to abstract grease. Leading from this vessel is a single-feed main, which runs the length of the boiler compartments. To each of the six boilers there is a separate feed pump which has its suction from the feed main. The steam pipe to the separate feed pump is taken from its boiler at a point about the normal water-level, there being, however, an interval swivelling pipe by which the level can be altered if necessary. If the boilers become too full, water, in place of steam, flows into the steam pipe. The pump steam cylinder thus becomes choked, and the action of the pump is all but stopped. When the waterlevel falls again, through evaporation taking place in the boiler, steam once more passes to the pumping engine, which thus recommences its proper functions. The exhaust from the pumps is not taken to the condenser, but into the feed main.

The policy of armoring these small craft has been a good deal discussed lately, the interest in the subject having been revived by some operations during the late war in the East. About 11 years ago Messrs. Yarrow & Co. built for the Japanese Government a small vessel, the Kotaka, which was protected by armor, and was, we believe, the first high-speed armored torpedo craft. It will be remembered that during the late war the Kotaka led two important torpedo attacks, and came through comparatively unharmed, whilst the unarmored boats suffered severely. The price paid by armor is, of course, loss of speed, but the Argentine naval authorities are evidently of opinion that it is advisable to sacrifice something in swiftness in order to gain protection. In our own navy there are, as stated, no armored torpedo craft, it being held that the very thin armor, which alone can be used, is comparatively useless, or worse than useless, whilst it destroys the most valuable quality in these little vessels-their paramount speed. Speed, however, is a relative term. These Argentine destroyers are to steam 26 knots, which would be sufficient to enable them to perform their ostensible duty of putting out of action torpedo-boats proper. It is now generally recognized, however, that destroyers are but torpedo-boats of a larger growth, and this is fairly well shown by the fact that the present vessels have each three torpedo discharges, which are certainly not intended for use against small craft. Whatever may be the intention of the designers,

66

however, one may be sure that no naval officer in command of a destroyer would lose the opportunity of bagging a battle-ship or cruiser. For such an opportunity the chief advantage of speed is that it enables the attacking boat to pass the zone of fire" very quickly. Armor naturally lessens this advantage, but whilst it detains a boat longer under fire, it would keep out a great many projectiles that might otherwise prove fatal. It is, of course, guns of the smaller natures that torpedo craft have most to fear. The very limited target they present warrants them in taking their chance of a blow from the larger and comparatively slower firing weapons. In any case no protection could be provided against these. The machine gun sends a stream of bullets which may almost be likened to a jet of water from a hose, and, once the range were obtained, would soon play havoc with the ordinary thin plating of the average torpedo-boat. It is to keep out these projectiles that 1⁄2-inch armor has been added to the Argentine boats. This armor entirely surrounds the engines and boilers, the bulkheads at the ends of the machinery space being also of steel 1⁄2 inch thick. The estimated speed of these boats, 26 knots, may be compared with the 30 knots of the unarmored destroyer Sokol, built by Messrs. Yarrow. The Russian boat, however, though the same length, was a foot narrower, and, moreover, was built of a special steel which enabled the scantling to be lightened.

Messrs. Yarrow have at present a very full yard, the whole of the work being done for foreign governments. There is in course of construction, in addition to the four Argentine destroyers, a large stern-wheel boat for the Russian Government, a twin-screw gunboat for Brazil, and six firstclass torpedo-boats for the Chilian navy, besides some smaller craft. At the present time we learn there are about 1100 men employed at the Poplar yard in the construction of these small war vessels.

[BRAZIL.]

BRAZILIAN WARSHIP BUILDING NOTES.

[MITTHEILUNGEN AUS DEM Gebiete des SeeWESENS.]

The following war-ships are building: Two battle-ships in France, three torpedo-cruisers and three first-class torpedo-boats in Germany, and two monitors in Brazil.

THE CARAMURA.

The torpedo-cruiser Caramura was launched at Kiel, April 1. The principal dimensions are: Length, 79 ms.; beam, 9.4 ms.; draught, 3.1 ms.; displacement, 1030 tons. Two triple-expansion engines with 6000 I. H. P. to give a speed of 23 knots. Armament: Two 10.5-cm. R. F., six 5.7-cm., and four 3.7-cm. Nordenfeldt R. F. guns; two 45-cm. broadside and one bow torpedo-tubes.

[SAN DOMINGO.]

GUNBOAT RESTAURACION.

Messrs. Napier, Shanks & Bell, Yoker, launched on the 15th inst. the twin-screw gunboat Restauracion, which has been built by them to the order of Messrs. Frame, Alston & Co., London, for the government of

San Domingo. The vessel, which has very fine lines, ram bow, and gunboat stern, is the second constructed by the same builders for the republic; but the new vessel differs from her predecessor, the Independencia, in being larger in size and with greater speed, and otherwise better adapted for war purposes, having barbettes fitted on the sides mounted with Hotchkiss quick-firing guns, similar guns being also mounted at the bow and stern. The Restauracion is 214 feet over all by 30 feet beam. Rooms are provided for the President and his suite, besides accommodation for officers and artillerymen. The machinery is being fitted by Messrs. Dunsmuir & Jackson.

BOOK NOTICES AND BOOKS RECEIVED.

A TEXT-BOOK OF ORDNANCE AND GUNNERY, prepared for the use of Cadets of the U. S. Military Academy. By Captain Lawrence L. Bruff, Ordnance Dept., U. S. Army. Published by John Wiley & Sons.

In the preface to this volume of 675 pages the author states that "the present text-book has been compiled with the object of presenting as clearly as possible the elementary principles of the course in Ordnance and Gunnery as taught at the Military Academy, and of so arranging it that it can be readily used for recitations in the section-room.

The contents are arranged in chapters as follows: I. Gunpowder and Interior Ballistics; II. High Explosives and Smokeless Powders; III. Guns; IV. Projectiles and Armor; V. Fuzes and Primers; VI. Exterior Ballistics; VII. Artillery Carriages; Theory of Recoil; VIII. Pointing; Probability of Fire; IX. Portable Arms; X. Machine and Rapid-fire Guns. Index. H. G. D.

HAND-BOOK ON NAVAL GUNNERY, by Cyrus S. Radford, Lieut., U. S. Marines; revised and enlarged with the assistance of Stokely Morgan, Lieut., U. S. Navy. Published by D. Van Nostrand Company, New York. The revised second edition of this excellent manual is well up to date. The book has already proven so useful that a frank criticism of the. errors of the present edition can do it no injury.

A serious blunder is made on page 19, where the Fletcher (modified Farcot) breech mechanism for large b. 1. guns is correctly described, but illustrated (with lettered references) by a plate of the older and quite different mechanism which it has supplanted.

The new telescope sight is well discussed on pages 38 and 39, but the answer in regard to compensation for drift is a little misleading, for the permanent angle of inclination of trunnions will differ in different guns, as it now does for their sight-bars.

A misnomer occurs on page 54, where an 8-inch turret mount is called a rapid-fire mount.

The statement on page 82 that 53-mm. H. R. C's are to be found on board ship might lead to the belief that there are some 53's in the U. S. Navy, whereas there are none.

It is stated in error on page 120 that brown prismatic powder grains are the same size for all calibers. The forms of smokeless powder grains described on page 123 have been discarded in favor of flat strips. The catechism on automobile torpedoes should be rewritten, now that the Bureau of Ordnance publications upon those weapons are available.

As evidences of careful attention to progress, there will be found in this edition a description of the Fletcher rapid-fire breech mechanism and of the new electric primers, with illustrations of each.