ON THE PERFORATION OF HARD-FACED ARMOR PLATES.
By Mr. C. A. Stone.
With the adoption of hard-faced armor the formulas for the striking velocity required by an armor-piercing projectile for the perforation of an armor plate of a given thickness become no longer applicable
These formulas presupposed that a projectile would perforate the plate unbroken and but little deformed. If the effect upon the projectile were small enough to be ignored, the differences between the results obtained at the Proving Ground and those to be calculated by the formula would be due to the differences in resistance of the plates tested. When the manufacture of homogeneous plates had reached a point of reasonable uniformity, and with uniformly good projectiles, these differences were comparatively small, and the conditions were such that a formula for the perforation of a homogeneous plate could be used, agreeing fairly well with the results obtained by practice, making due allowance for variations in quality of projectiles and plates.
With the universal adoption of hard-faced armor these formulas become no longer applicable. The object of the hard face of the armor was to break up and totally deform the projectile. If the hard face served this purpose the conditions were such that the formulas were of no use whatever, except for the purpose of determining approximately a velocity with which the plate would be perforated if the hard face did not break up and deform the projectile.
In the London Engineer of July 3rd, 1896, there is an article entitled "Herr Krupp on the Perforation of Steel Armor," in which is given what is called "a fairly sound rule-of-thumb," that for steel plates with hardened faces 2000 f.s. striking velocity will give about the caliber perforation, and other velocities proportionately. An oil-tempered nickel-steel plate 6 or 8 inches thick would probably be perforated with a 6 or 8-inch armor-piercing shell, weight one hundred or two hundred and fifty pounds, with a striking velocity of about 1450 f.s. For a 6-inch plate and 6-inch gun the DeMarre formula would give a velocity of about 1375 f.s. When, therefore, it is stated that it would take 2000 f.s., although the weight of projectile is not given, it will be seen what a greatly increased velocity is required for the perforation of a hard-faced plate; a velocity equivalent to the perforation of a homogeneous plate probably of 60 per cent, greater thickness. A large part of this increase is due to the breaking up of the projectile by the hard face. When projectiles, capped or otherwise, are obtained which uniformly perforate the present hard-faced armor plates unbroken and undeformed, this difference will be decreased. 8-inch armor-piercing shell are now being furnished the Navy Department, under contract, which have perforated, unbroken and but little deformed, an 8-inch hard-faced plate when fired with a velocity of 1900 f.s., which is somewhat greater than is required when the shell is unbroken and but little deformed.
If by the development of the shell its efficiency against hard-faced armor becomes equal to that which it attained against homogeneous armor, it is probable that this percentage of increased thickness mentioned above, namely, 60 per cent., would be reduced to 30 or 40 per cent., so that an 8-inch hard-faced plate would be equivalent to an ii-inch oil-tempered plate. If these two plates thus offered exactly the same ballistic resistance to an 8-inch shell, and if we suppose the body and back of the 8-inch hard-faced plate is of the same material as the 11-inch homogeneous plate, it will appear that we are claiming for the hard face of the 8-inch plate, about ¾ inch thick, an effect equal to the front 3 ¾ inches of an 11-inch plate. Of course the increased strength and hardness of the ¾-inch thickness would not, of itself, be equal to the resistance of 3 ¾ inches of the homogeneous plate; but its effect on the face of an 8-inch plate is equal to that of the 3 ¾ inches on the 11-inch plate, principally because it prevents the flow of the metal to the front on impact. The front 3 or 4 inches of an oil-tempered plate offers comparatively but little resistance to the projectile on impact, the section of the point being small, and the metal free to flow to the front around the point of the shell, producing the front bulge and fringe until the perforation reached such a point that the direction of least resistance of the metal is towards the rear. It is by preventing this How of metal to the front that the hard face on the 8-inch plate enables it, with a thickness of ¾ inch, to contribute to the total ballistic resistance of the plate an amount equal to the 3 ¾ inches of the homogeneous plate to which it is compared. The dimensions 8 and 11 inches above used are for the sake of illustration, as we do not as yet know what thickness of hard-faced and homogeneous plates would offer the same ballistic resistance under different conditions.
HERR KRUPP ON THE PERFORATION OF STEEL ARMOR.
[REPRINTED FROM LONDON ENGINEER OF JULY 3, 1896.]
The investigation of the laws of perforating armor plates at high velocities has not been satisfactorily attempted. Artillerists have had to content themselves in all countries with empirical formula based on fragmentary evidence. For this, no doubt, obvious reasons may be urged. It may be said, first, that the plates often fracture, and so far the form of work done is changed, and still worse, that the shot break, that the trials are very costly and must be confined to the immediate object in view, and hence isolated results are obtained which do not lend themselves to the formation of series. The answer to all this is that the question could be investigated on a miniature scale, which would cost comparatively little, and so laws might be suggested such as would admit of verification by any trials which might take place on a large scale. We believe ourselves that almost all laws on such questions are thus established, and both on this and on the other side of the Atlantic the cry has been raised for something to be attempted, though hitherto without success. So far as we are aware, we all run very much in the same groove, and it is a curious spectacle. At Meppen, in a solemn German manner, is tried year after year how certain individual German plates behave under the attack of big German projectiles which will never be fired at these on service. At Givre, French shot make an animated onslaught on French armor. At Portsmouth or Shoeburyness, British projectiles attack British plates. At Indian Head the United States projectiles of Carpenter and Wheeler-Sterling prove their powers on Carnegie and Bethlehem armor. Rarely, indeed, is a plate attacked by any shot representing those which it could in any reasonable likelihood encounter in war. At one time Holtzer's shot were much used and formed a sort of international standard of comparison, but latterly this seems to have dropped out. Russia and some other powers, from ordering armor abroad, have brought the shot and armor of different countries into comparison occasionally; but generally speaking it might be supposed that each nation was mainly interested in isolated facts connected with the attack of her own plates by her own shot, and did not care to obtain more general information, either by experiment or by the establishment of laws and formula. In this condition of things, it is curious to note how such individual efforts as are made bring out similar results, though sometimes masked in the different shapes assumed, and by the use of different systems of units. In our issue of April 24th last we pointed out how similar are two formula proposed by Krupp and Tresidder, the real difference being that in the kit mer weight tells more than in the latter. It may be seen below that with projectiles of the same weight the formula become identical.
We may disregard all the constant factors, or allow them to flow, as it were, into one term, whose value will be determined once for all in practice. Next, supposing we are dealing with shot of similar form, it follows that the weight will be in proportion to the cube of the diameter; that is, for w we may substitute d3 X some constant; applying this to Krupp's as we now have it, and to Tressider's, we get in each case t2 = d2v2 X some constant; that is, they become identical, the sole difference between them having disappeared.
This is a little remarkable, having probably never been intended, and the two formulae having looked unlike in their original shape. We have, perhaps, a more striking instance of agreement in the case of a formula recently propounded by Krupp for use with the best and newest steel plates with hardened faces. This is taken from the translation of an article by Captain J. Castner, in Stahl und Eisen of April 1st, 1896. In continental units this is given as p v2 = 5800 a E2, where v is the striking velocity in meters, p the weight of projectile in kilos., a the diameter of projectile in cm., and E the thickness of the plate in cm.
This is said to have been first laid down at the Krupp Works, which may be true as applied to steel with a hardened face, but certainly is the oldest and simplest form of Fairbairn's equation, and the one on which a rule-of-thumb was based many years ago, as explained in the "Official Text-Book on Armor and its Attack," page 30, 31. This rule-of-thumb was then applied to wrought iron, and gave the best results when the sectional density of the shot was such that = 0.41, and when the striking velocity was not very far removed from 2000 foot-seconds. According to Krupp, we may now take it as based on the best formula that can at present be suggested, and we find the average for the six first armor-piercing calibers of Krupp's, which we take is 0.42, while for thirteen British it is 0.45. The striking velocity on service for heavier guns would probably not be very far removed from 2000 foot-seconds; so that a fairly sound rule-of-thumb ought to follow—depending on the constant—and this turns out such that we may say, approximately speaking of steel plates with hardened faces, 2000 foot-seconds striking velocity will give about the caliber perforation, and other velocities proportionately. Thus a 6-in, shot with woo foot-seconds may perforate 6-in, treated steel; with 1500 foot-seconds it may perforate 4 1/2-in.; with 1000 it may perforate 3-in., and so on. This amounts to putting the best steel equal to twice the thickness of wrought iron. In the absence of more trustworthy data this may be useful, but we need hardly say that it is only suggested, not at all established. It is possible that the hard-faced armor of the present day may crush less and tear more truly and completely than softer metal, and this suits the old formula, but with armor depending on its power to fracture the shot's point, and with shots at all broken, great elements of uncertainty must exist, and we are brought back to our need of systematic experiment in order to obtain any certainty.
ARMOR-PLATED TORPEDO BOATS.
[THE ENGINEER.]
A consideration of the duties to be discharged by torpedo-boats or torpedo-boat destroyers, and the results obtained in actual practice, lead us to think that far too much importance is being attached to mere speed. The torpedo-boat in all its forms is a compromise, like every other warship. We cannot have extreme speeds and several other good things as well; and it is very questionable, we think, if a speed of say 30 knots is worth the price paid for it. In actual service it is very improbable that it will be attained. We need not stop to explain why. The reasons are well known to engineers in the navy, and to most gunnery officers and sailors as well. They concern the quality of the fuel, the skill of the firemen, the load on board the boat, and the weather, besides certain points connected with the trim of the vessel and the state of the sea. On the whole it is far more likely that a boat which attains 27 knots on her trial trip will give 25 knots on service than it is that a 30-knot boat will give 27 knots at sea. But in any case it does not appear that these extravagant speeds possess any real fighting value, or, at least, not enough to compensate for the sacrifice made to attain them. It is obvious that a torpedo-boat attack made in daylight must be regarded as a forlorn hope. Every man taking part in it knows that the chances are a thousand to one that he will be killed. The difference between 28 knots and 30 knots speed will not augment the chance of escape by a decimal of one per cent. Attacks will almost certainly be made at night, not so much to save the lives of the crews of the torpedo-boats as to give them a chance to destroy the ships attacked. Here again the difference of a knot or two an hour is of no value as a means of safety; nor can it be said that extraordinary speed is necessary in a torpedo-destroyer to enable her to sink torpedo-boats. Under almost all circumstances she must be faster than a torpedo-boat because of her greater size; which will enable her to make better weather than craft of half the tonnage. This fact has been proved over and over again during the naval manoeuvres.
Now, other things being equal, the sacrifice of about one knot an hour will enable the builder to protect the whole engine and boiler space with hard steel armor half an inch thick. This will form a very respectable protection. It will not be easy to strike it otherwise than at an angle, and consequently it can defy all the small natures of quick-fire guns, such as the Maxim automatic, and the like. Leaden projectiles will have no effect whatever. Such armor will add enormously to the safety of the crews, and will thereby promote in more ways than one the efficiency of the torpedo-boat, or rather destroyer. The bravest of brave men may well become excited and flurried when they know that they are going away in a craft which may be riddled with rifle bullets. The chance of striking a torpedo-boat with comparatively large projectiles is small; and hitherto ships have trusted mainly to their nets, and to a hail of small shot, so to speak, for the defense. But by enabling the torpedo-boat to defy the small-arm men and the little machine guns, more than one-half the risk of an attack is removed. The attackers may go into action with a prospect of coming out alive; and the fact will give confidence and coolness, and promote efficiency in a very tangible way. Sailors are really just like other men, and we have only to put ourselves in the place of the crew of a torpedo-boat to realize how important and valuable the half-inch of armor may be.
In our own Navy we always follow the lead of some one, we seldom initiate anything; we develope or improve, we do not originate. That is to say, the Lords of the Admiralty are either extremely cautious or excessively conservative. Consequently we have as yet no plated torpedo-boats; but such things are by no means new. Messrs. Yarrow & Co. built for the Japanese Government a boat, the Kotaka, about eleven years ago; all her engine-room and boiler-room space is protected with armor 1 inch thick. This boat did excellent service during the recent war. She is very nearly of the same dimensions as the modern destroyer. We do not know what her speed is, probably about 22 knots, or a little less. That was a high velocity eleven years ago. It seems to have been sufficient to enable her to do what she was expected to do. Messrs. Yarrow & Co. have just completed and tried a destroyer for the Argentine Government, which is provided with 1/2-in, steel armor over the engine and boiler-room space. This entails the loss of about three-fourths of a knot per hour. The vessel is the Santa Fe; she is the first of several, and her official trial took place on Thursday week. The trial consisted of a three hours' full-speed run, carrying a load of 35 tons, when a mean speed during the three hours of 26.5 knots was obtained. The dimensions of this vessel are 190 feet in length by 19 ft. 6 inches beam. The vessel is fitted with Yarrow straight-tube boilers, and the speed above named was obtained with 1 1/4-in, air pressure in the stokehold. The Argentine authorities expressed themselves in every way thoroughly pleased with the result, the speed exceeding by half a knot that contracted for.
Now, we think it can hardly be maintained that the price in the shape of loss of speed paid for this armor is too high. Without the armor she would have made, say, 27.5 knots. Can it be shown that the extra knot would have made her much more efficient? We think not. This question of efficiency must be regarded from two points of view. It is admitted by all naval authorities that the torpedo-boat, or destroyer, is far more likely to do good by frightening an enemy than in any other way. The circumstance that a few torpedo-boats are known to be in a port or harbor will effectually prevent any admiral or captain from attempting to blockade that port at night, whatever he may do in the daytime. He will probably get away to sea as darkness approaches. But it seems to be reasonable that an attack from armored torpedo-boats should appear to be a much more dreadful event than an attack by unarmored boats. Against a night attack much reliance is placed on the "riband of missiles" round a ship. If, however, the attacker can cross the riband with impunity, the danger incurred by the ship is much augmented. An admiral who might dare certain things against an ordinary torpedo-protected port would probably think twice before he risked an onslaught from armored torpedo-boats. This is one aspect of the case, and far more likely to be appreciated at its full value in real life than when stated in print. Another is, that leaving on one side all consideration for the lives of the torpedo-boat crew, it is clear that the longer she can be kept afloat in action the more harm is she likely to do. The argument which we have heard urged against plating such boats is that thin armor of this kind is quite useless against anything but the lightest missiles. We have endeavored to show that it is these lightest missiles which constitute the greatest danger for the torpedo-boat, and even steel projectiles 1 inch in diameter will not find their way through hard plates if they strike at an angle. In any case, the safety of the boat is augmented; the only drawback is a small sacrifice of speed. Those who are opposed to plating have to show that the loss of a knot or two in speed is too large a price to pay for the protection given in its stead.
EXPERIMENTS WITH MODELS AT THE BARROW-IN-FURNESS SHIP-BUILDING YARD.
[ENGINEERING.]
***A new departure in the work of design was made at the establishment when the company were asked to construct torpedo-boat destroyers of 27-knot speed, and the system organized by Mr. Adamson is specially interesting in view of its simplicity and the large measure of success that has been attained—the margin of accuracy comes well within the limits of practical success, and this, after all, is as much as can be said of most technical, as distinguished from laboratory experiments. The system is a modification of that introduced by the late Mr. Froude; but the apparatus is inexpensive, and instead of an inclosed tank, the Devonshire Dock is utilized. The experiments were first made at Barrow in the winter of 1893, under the direction of Mr. George Brown, the assistant chief draughtsman, who has charge of the scientific work in the designing department. The data obtained were embodied in the design of the three 27-knot destroyers then built, and were amply confirmed by actual experience with the vessels when on trial. This success induced the builders to make similar experiments with the model of the later 30-knot destroyers.
The model is run with the assistance of a launch, the speed of the launch and of the model bearing a known relation to the speed of the full-sized vessel, and the mechanism for ascertaining the resistance is placed on the launch. The recording apparatus is illustrated by Figs. 1 and 2. It was, of course, inadvisable to tow the model behind the launch on account of the disturbance in its wake. A long spar or bowsprit was, therefore, rigged over the bow of the launch, the length of the projection being sufficient to keep the after end of the model about 4 feet in advance of the bow of the launch. The model is guided by rods at each end, these rods being free to swing fore and aft, while rigid in an athwartships direction. The rods hang from the spar into fore-and-aft guide slots of hard wood, projecting past the ends of the model. The necessity for these will be apparent to any one who has discovered the impossibility of towing a ship or boat in a straight fore-and-aft line without the help of the rudder or some other means of steering. A model free but for a towline fixed to its extreme fore end will, when towed, swerve to one side or the other indifferently, and will travel along in a half-sidelong fashion.
The model is towed at the lower end of a long balanced lever, the connection being a wire link hooked to the lever, and to a bulkhead left in the model when originally hollowed out. The lever, left free to swing round its center in a fore-and-aft vertical plane, is pivoted at its center on the spar, and its upper end is connected to the recording gear by a fine wire cord, which previous to using is thoroughly stretched. Exactly half-way between the center of the lever and its lower end another wire is connected to the lever and led aft over a pulley on the stern of the vessel. From the aft end of this wire is hung a scale pan to which is attached a permanent weight to keep the wires tight and put a slight initial strain on the spring. This helical spring is introduced into the upper wire, and its extension when the model is towed gives a measure of the resistance of the model. The extensions of the spring are recorded on an exaggerated scale on a paper stretched round a drum driven by clockwork. The markings are made by a small pen attached to one end of a light wooden lever, the other end being fastened to the wire immediately forward of the spring. The clockwork is so arranged as to give about one revolution of the drum in the time taken to pass over the measured distance at full speed. To obtain a scale by which to read the extensions of the spring in pounds resistance, weights of known specific gravity are placed in the scale pan at the stem of the model-2 lbs. in the pan being equal in effect on the spring and pen to 1 lb. resistance of the model. By marking on the paper the position of the pen with different weights in the pan a scale of pounds resistance was obtained.
When running, the clock is started, and as soon as the measured distance is reached the pen is lowered on to the paper on the revolving drum, tracing an oscillating line. The oscillations are, of course, partly due to the natural oscillations of the spring and partly to the vibration of the launch and the spar due to the beats of the propelling engines of the launch. The mean of the oscillations, obtained by integrating with planimeter, gives the resistance of the model at that particular speed. The results are plotted in the form of a curve as resistance in pounds in terms of the speed of the model in feet per second. The spots, owing to the causes mentioned later, do not give a fair curve, but by taking plenty of spots, and running a mean curve through, the error is minimized.
The total resistance, of course, combined two elements—surface friction and wave-making—the relations between these two for ship and model following a different law of comparison, and being in different proportions. Froude's experiments give a means of calculating the amount of surface friction resistance for both ship and model, the residue of the model's resistance being wave-making, which, for corresponding speeds, varies directly with the displacement, or as the cube of the dimension. Dealing with the two parts separately, the total resistance of the ship is obtained, which, expressed in foot-pounds per minute, gives the effective horse-power or horse-power actually required to drive the vessel at the speed. To this has to be added an allowance for the power lost or otherwise used in driving pumps, overcoming friction, etc., an amount which varies with the type and speed of engine and propellers, but in a case of this kind should not be much more than 40 per cent. of the total indicated horse-power.
It is not contended that the results so arrived at are absolutely correct. With comparatively rough gear in an exposed dock such consistent and steady results were not anticipated as are obtained with the elaborate and delicate machinery in use in covered-in experimental tanks. The aim was to furnish in the case of such unprecedentedly fast craft some independent and reliable check on the estimates for power, so as to avoid the risk of serious error. As a matter of fact, the results exceeded all expectations, particularly in view of the difficulties, and especially the fact that the model was run in a large dock in which the water is rarely absolutely smooth—a very slight ripple on the dock being, in proportion to the size of the model, a rough sea. It is, perhaps, unnecessary to remark that the experiments were only made in fine calm weather when the dock was as nearly as possible smooth. Again, the fact that no account is taken of the effect of the screw propellers on the vessel's resistance is in itself a serious drawback; but, as we have said, it gives a good independent check on estimates of power for exceptional speeds, and therein is great advantage.
The launch used has a maximum speed of just over 7 knots, which, with a model 1/20th of the full size—the scale used in the first experiment—corresponds to a speed of 31 1/2 knots for the ship. As it was considered desirable in the case of the faster destroyers to have results up to a speed of about 35 knots, the scale of the new model was made 1/24th of the full size running at 7 knots, this corresponds to a speed of 34 1/4 knots for the ship. Better results would probably have been obtained with a larger model, but the size was restricted by the speed of the launch used for towing the model. The speed of the launch was, for want of a better method, measured by the time taken to pass a known distance, marked on the side of the dock in the usual way by two pairs of posts set square off the course. The engines were set to the desired speed some time before reaching the measured course, and not touched until the run was over, so as to have a constant speed on the run.
VISIBILITY OF LIGHTS AT SEA.
A commission appointed by the German Government to study the visibility of lights at sea has concluded from the means of numerous experiments that a white light of 1 candle-power is visible at a distance Of 2800 yards on a clear night, and at a distance of 1 mile only on a rainy night. It was further found that when a white light of 1 candle-power was visible at a distance of 1 mile, one of 3 candle-power was visible at 2 miles, of 10 candle-power at 4 miles, and of 19 candle-power at 5 miles. A green light of 1 candle-power is visible at 0.8 of a mile, and the lighting powers of such lights to be seen at distances of 1, 2, 3, and 4 miles must be 2, 15, 51, and 106 candle-power respectively. The best glass is clear blue-green, whilst for the red light a copper-red is, it is stated, the best.
THE PNEUMATIC PAINTER.
[ENGINEER.]
At 86, Charing Cross-road, London, there is on view a new machine for applying paints, enamels, ships' compositions, tars, and other liquids, by means of pneumatic pressure. The machine comprises a closed paint receiver, containing the paint or liquid to be used, into which compressed air is forced through a tube for the air supply. This causes the paint to be driven along a metallic tube to the nozzle, where it is met by a blast of air which atomizes the paint and projects it in the form of a fine spray. Owing to the pressure with which the paint is applied, it enters into the smallest interstices of metal work, and prevents oxidation in partially concealed parts, which sometimes escape the most careful hand work. A surface of 11,200 square feet was recently painted with two small power machines in 6 1/2 hours, equal to almost 100 square yards per hour for each machine.
OIL ENGINE SIGNALING PLANT ON U. S. LIGHTSHIP, NO. 42.
[SCIENTIFIC AMERICAN.]
Hitherto it has been the custom to have the whistle on this light-ship blown by steam. This necessitated the use of coal, which involved much expense and trouble. Often great delay would be experienced in the transfer of-coal from the tender to the light-ship. An efficiency exceeding four or five pounds of coal to the horse-power hour could not well be looked for. If a fog was seen approaching or forming, the boilers would have to be fired in anticipation, and before they were well started the fog might cease. This and similar conditions of the service involved in the course of a year many hours of idle steaming and many tons waste of coal.
The new plant with oil engines avoids to a great extent these troubles. The consumption of oil per horse-power hour, is only one pound. To the great economy directly due to this fact is superadded the feature that no idle steaming is needed. The engine can be started in fifteen minutes, and the oil consumption ceases the instant the engine stops. A quantity of oil very much less than the weight of coal requisite for corresponding service is required.
The plant is a development of one already in successful use on another United States light-ship. In the hull of the vessel are installed two 25 horse-power Hornsby-Akroyd oil engines. These are explosion compression engines whose most distinctive peculiarity is the method of ignition of the charge. Back of the cylinder is a vessel forming a sort of continuation of it and acting as a retort. To start the engine, a powerful oil burner is lighted beneath the retort. In ten or fifteen minutes, for a 25 horse-power engine, the machine can be started. Oil is admitted to the now hot retort. It is at once vaporized, mixes with the air, and, as the engine is started, explodes, giving an impulse to the piston. The regular cycle of the compression gas engine is followed. The retort keeps hot by the heat of the explosions, the lamps being only used to start the engine, and it may even rise to redness; its direct heat effects the ignition. There is no battery and spark coil and no troublesome ignition tube. It is calculated that 15 horse-power can be developed for twelve cents an hour. This power is that approved of by the engineers for light-ship signaling.
The cooling of the cylinder of the engine while running is effected in the usual way by water caused to circulate around it through passages in the metal. Fresh water is employed, as the danger of salt deposits precludes the use of sea water. To avoid waste, the same water is used over and over again, being cooled by a surface condenser supplied with a constantly changing supply of sea water.
To each engine is connected a single-acting air compressor. The air can be used as fast as compressed to blow the whistle. To make provision for instant use of the whistle, as for a very sudden fog, two tanks of boiler iron, each one twenty feet long and three feet in diameter, are provided, which are charged with compressed air by the compressors. Ten cents' worth of oil will charge the tanks to their full capacity at 60 pounds to the square inch. The air contained is sufficient to keep the signal whistle in operation for twenty minutes. This period gives ample time to start the engine, so there should never be any delay in getting the whistle in operation.
The expansion of compressed air produces a lowering of temperature, which reduces the volume of the air. As the work done depends on the volume, the diminishing of it involves a loss in efficiency. The whistle, which is of the bell type, and which is placed about amidship over a deckhouse, has beneath it a reheater through which the air must pass. The exhaust from the engine passes through the same reheater, and so raises the temperature of the air and overcomes, to a greater or less extent, the cooling of the air due to its escape from compression. This feature not only is of economical value as utilizing the waste heat of the engine, but it tends to overcome another trouble. It has been found that an air whistle when the temperature fell to 18° F. would become clogged with ice. The heating of the air tends to prevent this. Moreover, the exhaust escapes into the air just forward of the whistle, and will do much to keep it warm and in condition to operate well.
Before reaching the whistle the air passes through a reducing valve, then through the reheater and then through the whistle valve. The latter regulates the admission of air so as to produce the characteristic signal, and is operated by clockwork. The latter operates a small valve which admits air into a cylinder with piston, which opens the whistle valve. When released by the clockwork it falls and closes the whistle valve. The clock carries a cam which, by its shape, produces the desired order of opening and closing the valve so as to give the signal. The officially designated fog signal for this ship has been a 12-inch steam whistle, with blasts of five seconds duration, followed by fifty-five seconds of silence. The air whistle is slightly modified, its annular opening for the escape of air being smaller than in the case of the steam whistle.
The engines' air compressors and storage tanks are exact duplicates of each other and are interconnected so as to allow the fullest possible degree of interconnection. It is quite improbable that any total break-down should occur. The oil is stowed away as received in five-gallon cans. The engine supply is taken from a tank below the engines, into which the cans are emptied by hand.
A NEW FINDING LIGHT FOR WAR VESSELS.
[ELECTRICAL ENGINEER.]
The French Mediterranean squadron has just made an interesting experiment with a novel light, the invention of a French naval officer. The sailors call it "the rat-trap light." The squadron left Marseilles on the 20th of August, at 5 o'clock in the evening, leaving behind the torpedo destroyer Faucon, which was to start 3 hours later and hunt it up. At 8 o'clock the Faucon weighed anchor and steamed out in pursuit with all lights extinguished except this novel affair, the ratière. Nobody on board knew the direction the squadron took, but at 1 o'clock in the morning the Faucon joined it.
The "rat-trap light" is a thing of small dimensions placed in the stern of the vessel above the wheel. No other light is permitted on board. It throws out an electric light which cannot be seen on the right or left of the ship, and can only be discovered dead ahead under certain conditions known to the seeker. By means of this invention night signals can be made when rockets or flash-lights might be useless or liable to betray the position of the fleet to the enemy. It can also guide a squadron in line, with all other lights out, even in dangerous latitudes.
The French Navy alone possesses this light, and the Admiralty evidently attaches great importance to it, judging by the precautions that are taken to guard it against discovery. The commander of the ship and one sworn officer alone handle it, and it is kept on board in a special apartment, of which the commander holds the key.
SMOKELESS POWDER IN WAR.
[ARMY AND NAVY JOURNAL.]
Military Information Division, No. 9, contains an article on "Smokeless Powder: Its Influence on Tactics." We are told that the advantage which cannot be denied in smokeless powder is that it will facilitate the control of officers in command of units; before, when all was enveloped in smoke, they could neither see the enemy nor their own men. Now this will not happen. By means of signals they will be enabled to make themselves understood by their subordinates; they will not stumble unexpectedly upon obstacles which smoke concealed, and will find it less difficult to keep in touch with collateral units whose movements can be seen. Smokeless powder will give a clear field of fire, but there must always remain the difficulty of accurately judging distances, and, above all, the fact that the number of soldiers who shoot well is very small, the majority not even taking aim.
It is not believed that the use of the new powder will render necessary any essential modifications in the tactics of small bodies, and as the supporting line loses the protection of smoke its position will become more precarious. In the future, as in the past, there will be only one way of deciding a battle, viz., to get to your enemy, or at least close enough to convince him that you have sufficient power to drive him from his position. The influence of smokeless powder with artillery will, perhaps, be greater than with infantry, since this arm generally fights at a distance, is more under the control of its officers, and is less demoralized by an enemy's fire; as a consequence it can take fuller advantage of scientific improvements. In certain countries and climates it will allow greater freedom in the use of artillery, and will enable fire to be opened indifferently from either flank. It will, besides, permit of guns being placed in tiers, since with the ordinary powder the smoke which the lower batteries produced on rising formed a cloud in front of the higher. Moreover, in the absence of smoke, which disclosed the position of guns and interfered with their service, they may in certain cases, without inconvenience, be placed at intervals of five or six yards only, so reducing the front of a battery to thirty or forty yards. Smokeless powder will more frequently permit the use of artillery en masse, because (a) it is easier to find positions, (b) the intervals between the guns can be reduced, and (c) there is no smoke to cause the difficulties already referred to. The unity of command is facilitated, and with it the concentration of the guns.
So far from smokeless powder rendering cavalry valueless on the battlefield, it will not seriously modify the conditions of its use. At first sight, indeed, the attack of infantry by cavalry, unprotected by smoke, appears a folly; but the rapidity with which cavalry moves makes it a difficult target. Furthermore, smoke prevented the infantry from seeing its approach. This will not now happen, and the sight of cavalry advancing at great speed may of itself be sufficient to cause a panic among infantry which is already on the point of giving way.
These are the opinions of R. J. Byford Mair, Lieutenant Royal Engineers, who says in conclusion: "We are of the opinion that the use of smokeless powder will not necessitate the introduction of radical modifications in the tactics of the three arms. As a German writer says, ‘Every advantage of the new powder is so evenly balanced by some disadvantage, and each disadvantage appears so small by reason of the attendant advantages, that the future will not differ from the past in any important point.' It will exact stricter discipline in armies and increase the probabilities of success for the side which is braver, better instructed, and more skillfully led. More than ever, victory will be gained by those most worthy of it."
SPECIFICATIONS FOR SMOKELESS POWDER.
[ARMY AND NAVY JOURNAL.]
Specifications issued by the Army Ordnance Department for smokeless powder for the Krag-Jörgensen 0.30 caliber rifle require that it should show a mean velocity at fifty-three feet from the muzzle of not less than 1960 foot-seconds, and the mean variations of velocity must not exceed 20 foot-seconds, and the maximum pressure 38,000 pounds per square inch. The powder pulverized or subdivided into minute grains must withstand for at least fifteen minutes a temperature of 150° to 154° Fahrenheit without emitting acid vapors, as indicated by the slightest discoloration of a piece of iodide of potassium starch paper partially moistened with dilute glycerin.
The powder must also be proof against tests for moisture, dryness, and cold.
The powder must be uniform in quality, free from dust and other foreign substances. Other qualities, in regard to which such additional tests will be made as the Department may deem necessary, are required as follows: The powder must be practically smokeless; must not corrode the barrel or cartridge case, nor require an unduly strong primer for ignition. It must not leave a hard adherent residue in the bore, especially after rapid firing, nor a metallic residue due to action of heat on bullet or barrel.
It must not be sensitive to friction or shock, and must not be so friable as to endanger breakage of grains in transportation incident to service.
It must not contain ingredients known to be unsuited to form a safe and reasonably stable compound, and must admit of machine loading with the machines in use or that can be readily provided at the Frankford Arsenal, not exceeding a variation of 0.3 of a grain from the desired charge in fifty consecutive machine-loaded charges.
It must not show a tendency to agglomeration during storage. Powder which may be found defective in this respect, and which has not already been used in the manufacture of cartridges, will be returned to the makers at their expense, and deliveries of the powder under contract will be suspended. Other things being equal, that powder which produces the least heating of the barrel will be preferred.
SHOOTING UNDER WATER.
[INVENTION.]
The most curious experiment ever made with a piece of ordnance was at Portsmouth, England. A stage was erected in the harbor within the tide mark; on this an Armstrong gun of the 110-pound pattern was mounted. The gun was then loaded and carefully aimed at a target—all this, of course, during the time of low tide. A few hours after, when the gun and the target were both covered with water to a depth of six feet, the gun was fired by means of electricity. We said "aimed at a target," but the facts are that there were two targets, but only one was erected for this special experiment, the other being the hull of an old vessel, the Griper, which lay directly behind the target and in range of the ball. The target itself was placed only 23 feet from the muzzle of the gun. It was composed of oak beams and planks, and was 21 inches thick. In order to make the old Griper invulnerable, a sheet of boiler plates three inches thick was riveted to the water-logged hull, in direct range with the course the ball was expected to take if not deflected by the water. On all of these—the oaken target, the boiler plates, and the old vessel's hull—the effect of the shot from the submerged gun was really startling. The wooden target was pierced through and through, the boiler iron target was broken into pieces and driven into its "backing," the ball passing right on through both sides of the vessel, making a huge hole through which the water poured in torrents. Taken altogether, the experiment was an entire success, demonstrating, as it did, the feasibility of placing submerged guns in harbors in time of war and doing great damage to the vessels which an enemy might dispatch to such points for the purpose of shelling cities.
THE LARGEST SHIP IN THE WORLD.
[SCIENTIFIC AMERICAN.]
According to Prometheus, the largest ship in the world is building at the Vulcan shipyard in Bredon, near Stettin, Germany, for the Hamburg-American line. The same builders constructed the first large express steamer built in Germany, the Augusta-Victoria, of the same line. The new monster steamer has a length of 628 feet on the water-line, and is therefore considerably larger than the Campania, which is 600 feet in length between perpendiculars. The engines will have 27,000 horse-power and a speed of 22 knots is expected. The engines and boilers will also be furnished by the Vulcan shipyards. Construction has been commenced already.
THE ST. PAUL.
The American Line s. s. St. Paul arrived at Sandy Hook on August 14, in 6 days 31 minutes from Southampton. The course covered was 3046 knots, and the mean speed 21.08 knots per hour. The best day's run was on August 13, when 530.8 knots were covered. The coal burnt was 315 tons per day. The record of the Hamburg-American ship Fürst Bismarck for the same trip was 6 days 9 hours 43 minutes. The White Star steamer Britannic has also lowered her previous best record made 19 years ago with a passage of 7 days 7 hours 31 minutes.
SHIPS OF WAR AND NAVAL NOTES.
[THE UNITED STATES.]
SPEED TRIALS OF THE BROOKLYN.
The new armored cruiser Brooklyn on her builders' trial attained a speed closely approximating 21 knots, or about 20.97. The trial was made over the Government official trial course, from off Cape Ann, Mass., to a point off Cape Porpoise, Maine, and back. The measured distance between the two capes is 41 1/2 knots, thus making a full run of 83 knots. The outward run to Cape Porpoise was covered at an average speed of 20.66 knots, and the average on the return trip to Cape Ann was estimated at 21.28 knots. This gives a general average of the full run of 20.97 knots per hour. The engines are said to have worked admirably at all stages of the trip.
On Thursday, August 27, the Brooklyn underwent her official trial over the same course and eclipsed her first performance by nearly a full knot an hour, proving herself one of the fastest vessels of her class afloat. The vessel covered the 83-mile course at an average speed, allowing for tide, of 21.9117 knots an hour. For 7 knots on the return trip her speed rose as high as 22.9 knots.
The official report of the board appointed to conduct the trial contains these general conclusions:
That the vessel is sufficiently strong to carry her armor and the armament equipment, coal, stores and machinery prescribed by the Secretary of the Navy and indicated in the drawings, plans and specifications.
That the vessel is in all respects complete and ready for delivery in accordance with the requirements of the contract, except as to several items, the most important of which relate to ordnance equipments. The steering gear worked well, and the vessel exhibited good tactical qualities. The time of putting the helm hard over from amidship thirty-five degrees was fifteen seconds, and from hard over one way to hard over the other way, sixty-five degrees, was twenty-three seconds. The angle of keel was five degrees.
The time occupied in making the total run of 41.5 knots north is given as 1 hour 52 minutes and 26.34 seconds, and the 83 knots running south 3 hours 47 minutes and 8.86 seconds. The tidal corrections to the trial course made the distance through the water 82.9530 knots, and the time mean speed of the Brooklyn 21.9117. During the first run the maximum revolutions of the starboard engine were 138; port, 139; average revolutions, 136.4 for starboard; port, 137,2. For the second run the maximum revolutions of the starboard engine were 138.06; port, 140; average revolutions, 136 starboard, 136.5 port.
The builders, the Cramps of Philadelphia, earn a bonus of $350,000 under the terms of the contract. The Brooklyn is the last vessel to be built under the system of bonuses.
The twin screw cruiser Brooklyn was authorized in the act of Congress approved July 19, 1892, and has been built as an improvement on the designs of the New York. Her principal dimensions are: Length on the load water-line, 400 feet 6 inches; extreme breadth, 64 feet 8 1/4 inches; mean draft, 24 feet; displacement, 9271 tons. Her maximum indicated horse-power is given as 16,000; the tons per inch of immersion at normal draft and displacement at 41.19; normal coal supply, 900 tons, and bunker capacity, 1753 tons. Her maximum draft aft at lowest point of the keel, when she is ready for sea and all bunkers are filled, will be 26 feet 2 inches. Her engines are of the vertical triple expansion type, and four in number, two on each shaft, and in four compartments. The forward engines are so built as to be readily uncoupled from the after engines, to permit of cruising at low speed. The boilers are placed in three compartments, and are seven in number. Five of them are of the double-ended and two of the single-ended type. The hull is of steel, not sheathed. There is a double bottom, and close, water-tight subdivisions to about 12 feet above the water-line. The arrangement of the decks above water is such as to provide ample freeboard and berthing accommodations. The ship will have two military masts with fighting tops. She will have no sail power. Protection of the hull is afforded by a steel protective deck, worked from stem to stern, and supported by heavy beams. The bottom edges of this deck amidships are 5 feet 6 inches below the 24-foot waterline, the top of the deck rising to this line at the center of the vessel. On the slopes of the deck, over the machinery and boilers, the armor is 6 inches thick; on the horizontal portion, 3 inches thick. Forward and abaft the machinery and boilers, to stem and to stern, the deck at the thinnest part is 2 1/2 inches thick. Below the deck are placed the propelling machinery, steering gear, magazines, shell rooms and all that is known as the "vitals" of a war-ship: An armor belt 3 inches in thickness provides protection for the machinery and boilers. This belt extends from 4 feet above the water-line to 4 feet 3 inches below it. Within the 3-inch armor belt and the skin plating a band of cellulose 3 1/2 feet wide has been worked. This will extend the whole length of the ship in depth from the armor deck to the berth deck. Coal will be carried above the armor deck for a length corresponding to the inner bottom. This space, between the armor deck and the deck above, is subdivided by water-tight bulkheads into 38 coal bunkers. These are exclusive of cofferdams and passages. The space forward and abaft the bunkers has been subdivided by water-tight bulkheads for stores. A conning tower 8 inches in thickness will be carried in a suitable commanding position forward. It will contain a tube 5 inches thick running to the protective deck. This tube will afford protection to the speaking tubes, bell wires, etc.
The battery will comprise eight 8-inch guns, twelve 5-inch rapid-fire guns, twelve 6-pounder rapid-fire guns, four 1-pounder rapid-fire guns and four machine guns. The 8-inch guns will be mounted in four barbette turrets, placed one forward and one aft on the center line of the vessel and one on either side amidships. The guns in the forward and after turrets are to have a train of 310 degrees. Those in the side turrets can fire right ahead to right astern, or to train through an arc of 180 degrees. The center of the side turrets is distant from the center lines of the vessel about 23 feet. The armor forming the barbettes, which will protect the carriages, platforms and turret machinery, is 8 inches in thickness for a portion at least equivalent to the train of the guns of the respective turrets. The remaining portions will be about 4 inches in thickness. Under the turrets is to be found 3-inch armor supporting the tubes, which will also support the ammunition hoists. The armor of the turrets is 5 1/2 inches in thickness. The guns are so mounted that they can be supplied with ammunition and loaded in any position of train. The 5 1/2-inch guns are protected by fixed segmental shields 5 inches in thickness. The crews of these guns are to be further protected from explosive shells by splinter bulkheads 1 1/2 inches in thickness. Protection is afforded the smaller guns by shields and extra side plating. The Brooklyn's torpedo outfit consists of five torpedo-tubes, one in the bow and two on each side. Six torpedoes and a suitable allowance of guncotton for mines and miscellaneous purposes will be carried on board.
The contract price for the Brooklyn, exclusive of armor and armament, was $2,986,000. Her keel was laid on August 3, 1893, and under the original agreement she was to have been ready by February 11, 1896, but slow delivery of armor in the earlier stages of her construction delayed the completion of the vessel.
BIDS FOR BATTLE-SHIPS.
[IRON AGE.]
Bids were opened September 14 at the Navy Department in Washington for the construction of the three powerful sea-going coast-line battleships provided for by act of Congress approved June 10 last. By this act the cost of the vessels, exclusive of armament, was limited to not more than $3,750,000, and one of the vessels was to be built on the Pacific Coast, provided a reasonable bid was received. Congress specifically stipulated that the award be made and contracts signed by October 8. The following bids were received:
John H. Dialogue & Sons, Camden, N. J., one battle-ship for $2,661,000.
Bath Iron Works, Bath, Maine, one battle-ship for $2,680,000.
Newport News Shipbuilding & Dry Dock Company, Newport News, Va., one battle-ship for $2,595,000.
Union Iron Works of San Francisco, one battle-ship for $2,674.950.
William Cramp & Sons' Ship & Engine Company, Philadelphia, one battle-ship for $2,650,000; two battle-ships for $2,650,000 each.
This means that the Cramps of Philadelphia, the Newport News Company and the Union Iron Works of San Francisco will each receive a contract for one battle-ship. The award to the San Francisco firm, whose bid is slightly in excess of those of John Dialogue & Sons of Camden, and of the Cramps, will be made on account of a difference of 4 per cent. allowed in favor of Pacific Coast bidders to cover cost of transportation of materials across the continent. This allowance would, for purposes of comparison, bring the San Francisco bid down to $2,598,982, or within $4000 of the lowest bid and considerably under that of the Cramps. The closeness of the various bids and the fact that they were all more than $1,000,000 under the margin allowed was a noticeable fact, showing that figuring on the cost of the work had been very exact.
It was rumored just before the bids were opened that several of them would contain the stipulation that the proposal was made only in case the Government would enter into an agreement to pay in gold, but on examination none were found to contain any such clause. All the companies pledged themselves to give bond in a penal sum equal to 15 per cent. of their bid, and each bid was accompanied by certified checks which, when taken in charge by Judge Advocate-General Lemly, were found to aggregate $460,000. In comparison with the prices secured for the battle-ships Kearsarge and Kentucky, which are now being built at Newport News for $2,250,000 each, the bids to-day show a slight increase. The bids for these two ships, however, were characterized by a wide diversity, and the exceedingly low estimates of the successful bidders, the Newport News Company, caused considerable surprise at the time. The rise in the price of coal in the interval also accounts in a measure for the slight increase in the present bids.
The three new battle-ships are to be combinations of the best features of the Iowa and the Kearsarge types, with sundry improvements. Their general dimensions and principal features are as follows: Length on water-line, 368 feet; beam, extreme, 72 feet 2.5 inches; freeboard, forward, 19 feet 6.9 inches; freeboard, aft, 13 feet 6 inches; normal displacement, 11,525 tons; mean draft, normal displacement, 23 feet 6 inches; indicated horse-power (estimated), 10,000; speed in knots an hour (estimated), 16 knots; normal coal supply, 800 tons; total bunk capacity, 1200 tons.
No premiums are offered for increased speed, but a penalty at the rate of $25,000 a quarter knot is imposed for the first half knot below the maximum requirement of 16 knots. It is proposed to name these ships California, Alabama, and Pennsylvania.
TORPEDO-BOAT No. 6.
Torpedo-boat No. 6, the first of the high-speed torpedo craft authorized for the Navy, was launched September 9 from the works of the Herreshoffs, at Bristol, R. I. In view of the launching the Secretary was cabled on Tuesday for instructions. In his response he directed that the vessel be christened Torpedo-boat No. 6. The officials at the Department interpret this to mean that the Secretary has finally decided to designate all future torpedo-boats by numbers. If all the torpedo-boats for which bids are soon to be opened are built, there will be twenty-one vessels of this class on the Navy ship list, of which, according to the new programme, only three will have names—the Cushing, Ericsson, and Stiletto.
THE NEW TORPEDO-BOATS.
[IRON AGE.]
In the present appropriation for the Navy provision is made for the construction of three torpedo-boats to cost in all not over $800,000, and for the construction of not more than ten other torpedo-boats with a total cost limit of $500,000. The boats are to be throughout of domestic manufacture, and no premium is offered for excess of speed. The contracts for the construction of these boats must be made on or before the 8th of October, 1896. The three boats first mentioned are to have a speed of 30 knots an hour and to maintain an average of the same for that period under condition to be prescribed by the Secretary of the Navy. Bids for these boats are invited upon plans to be submitted by the builder, including the engines as well, and the contract price is to include the boats complete in all respects, excepting sea stores and ordnance and ordnance outfit of all kinds. Omitting the necessary dimensions of rapid-fire 6-pounder and 1-pounder guns and torpedo discharges, together with weights and sizes of ammunition cases, the bidder is unhampered in every particular, and to his judgment and designing skill is left the planning of these craft. There will be two conning towers, one forward and one aft, in convenient positions; and accommodations will be provided for four commissioned officers and an adequate crew. The boats will be lighted by electricity, but there will be no search-lights.
The exact number, size and speed of the smaller boats not being fixed in the act of Congress, the Department will entertain bids for boats of two separate types, provided always that the total cost of these boats, including ordnance supplied by the Government, does not exceed $500,000. Type No. 1 requires an average speed of not less than 20 knots, to be maintained for two consecutive hours. They will have two conning towers, or sighting hoods, placed in convenient places forward and aft. The freeboard forward to be not less than 4 feet 3 inches; and accommodations must be provided for two officers and an adequate crew. The coal capacity must be at least 16 tons.
The following approximate dimensions are given: Length on load line, 105 feet; beam on load line, 12 1/2 feet; mean draft, 4 1/2 feet; displacement, about 68 tons; indicated horse-power, about 850; speed per hour, 20 knots. Armament: Two single deck torpedo guns, one 1-pounder rapid-fire gun, two automobile torpedoes; 180 rounds 1-pounder ammunition.
If the speed fall below 20 knots an hour, and exceed 19 knots, the boat will be accepted at a reduced price. If below that, acceptance at a lower price will be in the discretion of the Secretary.
Type No. 2 requires an average speed of 22 1/2 knots an hour, to be maintained for two consecutive hours.
The following approximate dimensions are given: Length on load line, 140 feet; beam on load line, 14 1/2 feet; mean draft, 4 3/4 feet; displacement, about 105 tons; indicated horse-power, about 1700; speed an hour, 22 1/2 knots. Armament: Three single deck torpedo guns, three 1-pounder rapid-fire guns, four automobile torpedoes, 540 rounds 1-pounder ammunition.
If the boat attains a speed of 21 1/2 knots she will be accepted at a reduced price. If the speed fall below that the boat may, at the discretion of the Department, be rejected, or accepted at a reduced price.
[NEW YORK HERALD.]
It is virtually assured that the contracts for the new 30-knot torpedo-boats will be awarded one each to the Union Iron Works, of San Francisco; the Bath Iron Works, of Bath, Me., and the Herreshoff Manufacturing Company, of Bristol, R. I. The two last named companies submitted plans for boats of each class, but the Union Iron Works bid only for the 30-knot boats, presenting plans of a craft of 273 tons, to be constructed in accordance with the ideas of the Department, for $227,500.
The Bath Iron Works people propose to turn out a vessel of 230 tons, and are willing to furnish a guarantee for a speed of 30 1/2knots, or pay a forfeit of $10,000 per knot. Their price is $235,000.
The awards for the ten smaller craft of 20, 22 and 22 1/2 knots' speed are likely to be divided among the Providence Steam Engine Company, the Charles Hillman Ship and Engine Company, Philadelphia; Wolff & Sewicker, Portland, Ore.; Lewis Nixon, Elizabeth, N. J.; Moran Brothers, Seattle, Wash., and the Columbia Iron Works, Baltimore, all these companies having submitted satisfactory proposals.
MANOEUVRES OF THE NORTH ATLANTIC FLEET
[ARMY AND NAVY JOURNAL, AND REGISTER.]
Under date of the 27th of July, Admiral Bunce has issued to the North Atlantic Fleet the following circular letter in relation to coming evolutions and exercises of the fleet:
FLAGSHIP NEW YORK, FIRST RATE,
NAVY YARD, NEW YORK, July 27, 1896.
GENERAL INSTRUCTIONS.
1. Attention is called to Squadron Circular Letter No. 24, December 28, 1895.
2. To insure ships keeping position, the movement of the guide must be constantly observed. Helm and engines must be moved promptly to regain proper position. Ships must not lag behind. The speed cone should be moved promptly to indicate the action of the engines.
3. No officer should be satisfied with anything less than absolute exactness of position.
4. The line of bearing for alignments will pass through the foremasts of ships.
5. In case of separation by reason of weather or accident to motive power, ships will rejoin the squadron at the port to which it is proceeding.
6. Boards, in accordance with Squadron Circular Letter No. 7, Sept. 22, 1895, will be organized. Suggestions as to any change in the manner of performing the different evolutions, and as to the organization and disposition of the different elements of a fleet are especially desired. Reports in accordance with Squadron Circular Letter No. 56 will be made on the forms furnished, and will be submitted to the commander-in-chief with such suggestions and criticisms as commanding officers may desire to make. These reports will be submitted on the fourth day after arrival in port. The text of the signal will be stated in the reports.
PROGRAM OF SQUADRON EXERCISES.
(a) Swing ship for compass error.
(b) Determine turning circles by sections in accordance with squadron instructions. Ships whose circles have been determined for the designated speeds will not be required to take them again.
(c) Preliminary drills will follow generally the order and sequence of the program of section exercises of June 15, 1896, a copy of which is inclosed.
(d) Regulating the speeds of the engines. The squadron will steam in line or column at different standard speeds. Ships will regulate their speed by that of the flagship, noting the revolutions required under the existing conditions of wind and sea to do so as a standard, subject to alterations, which a change of this condition may make necessary.
(e) Sound signals. Attention is called to the rules for these signals in the introduction to the General Signal Book. In compound formations the signal will be repeated to the nearest ship, taken up by the next ship to her in the formation, etc. Example: In double line No. 4 will be followed by No. 8, then No. 7, etc.
[Then follow the signal numbers to be used for various formations and evolutions.]
(l) In every formation the squadron will be exercised in changing direction or front and in changing course simultaneously or in succession.
The squadron will be exercised also in echelon formations, single and double, and in section formations.
Exercise at general quarters, fire quarters, collision drill, both day and night; clearing ship for action and man overboard.
Sub-caliber and torpedo practice at stationary and moving targets.
Target practice with main and secondary battery—moving or stationary target.
Squadron Circular Letter No. 24, referred to in the order, prescribes certain rules regarding the execution of manoeuvres. Circular Letter No. 7 provides that a board of three line officers shall be appointed on board each ship to observe carefully all evolutions and note difficulties or defects in methods. Circular Letter No. 56 says that the time required to execute every evolution shall be recorded, with the helm angle and other observations, so that the records may show when a manoeuvre is impracticable or clumsy, and which one of two or more methods is the best.
The vessels of the North Atlantic Squadron, under Adml. Bunce, which left the port of New York on Aug. 1, for evolutions at sea, returned on Aug. 23, and anchored off Tompkinsville, S. I., the fleet being increased by the addition of the Texas and Maine, the ram Katandin and the monitor Terror, the fleet taking part in the reception of Li Hung Chang. The squadron, after it steamed down the coast on Aug. 1, spent nine days in naval tactics and signaling with flags and whistles, and at night with the electric system of incandescent bulb lights. The ships put into Hampton Roads and coaled, and on Aug. 15 sailed for New York. On the way up they indulged in squadron evolutions and target practice. The capabilities of the ships and their officers were tested thoroughly in three days of hard drilling. The manoeuvring, it is said, was accomplished without the slightest hitch. During the practice firing the concussion aboard the battle-ships Indiana and Massachusetts is described by their officers and men as terrific. The target was about twenty-five feet high and fifteen feet wide at the base. The vessels of the squadron passed and repassed it at a distance of 2000 yards, running about eleven knots. The New York led the column, and, as she got in range, she blazed away with her forward battery, following it up with a cannonade from her waist, and finally from the guns of her after division. In the firing the Raleigh, it is reported, won the honors, demolishing the target early in her firing. When the Indiana steamed up within firing range of the target and began to shoot, her 2000-pound anchor, unbent from the cable, was blown from the port bow and thirty feet into the air by the mighty shock caused by the discharge of the 13-inch gun fired ahead. In the torpedo practice, buoys were placed a short ship's length apart, and, at a speed of six, nine and eleven knots, each ship fired her torpedoes. The target was 400 yards from the ships, and each ship had three shots at it. Every torpedo, it is said, would have hit an ordinary war vessel. After the torpedo firing the squadron steamed slowly northward, indulging in squadron drill until near Sandy Hook.
[NEW YORK HERALD.]
The target practice, each ship steaming past the target at a speed of nine knots and firing as rapidly as possible consistent with good aim, was an innovation that gave officers and men some conception, at least, of the conditions of actual battle, as far as the service of the guns was concerned. In some cases the rapidity of fire was much greater than had been anticipated, and this fact has led to an investigation of the ammunition supply of the different ships to ascertain how long they could keep up such a fire before the full allowance of ammunition stowed in their magazines would be exhausted.
The table is not intended to show the relative merits of the different crews, and could not be used to make such a comparison, except in the matter of rapidity of fire in the case of ships of the same class, with guns mounted and controlled in the same manner; but it gives some idea of the time during which guns of different caliber on board each ship could be kept in action at a range between 2200 and 1500 yards, firing rapidly, with the present allowance of ammunition.
For instance, the six 8-inch guns of the New York could fight for seven hours and two minutes, her twelve 4-inch guns for two hours and sixteen minutes, and her eight 6-pounders for three hours and twenty minutes. In this case the guns of heavy caliber could be kept in action longer, with the present ammunition supply, than the guns of small caliber. And this would seem to be right, because the heavy guns would begin the action at long range and be called upon before the smaller pieces would become effective.
But in the case of other ships this condition does not exist, and this fact suggests the necessity for readjusting the allowance of ammunition for ships in accordance with some sound rule. For instance, the ten 5-inch guns of the Raleigh, which constitute her main battery, would exhaust all their ammunition in the short space of one hour and thirty-one minutes, while her 6-pounders could maintain their fire twice as long. It is rather startling to find that a ship which keeps up a powerful, rapid and well-directed fire upon an enemy may be helpless for lack of ammunition in so short a time. If the gun is to win in future battles at sea—as all authorities now contend—it must have an ample allowance of ammunition.
In the case of ships on foreign stations, or far from their base, the question is a serious one. It would seem that there must be ammunition supply ships, as well as store ships and colliers, for the service of a modern fleet if the latter is to be prepared to fight more than one battle, or even one. So much space has been given to engines, and so little to coal, that it is hardly possible to increase the ammunition supply by using a coal bunker for that purpose, except in the case of ships on the home coast. This is another unfortunate result of the craze for speed—speed that would not, and could not, be used in actual battle. It has in some cases robbed ships of the guns and the space for the ammunition that would be used. The emergency of battle has not always been properly considered in designing ships of war. In many cases the ability to run has been secured at the expense of the ability to fight.
Comparing the endurance of the Newark and the Raleigh, the former firing thirty-nine heavy projectiles in twenty-one minutes and the latter 213 heavy projectiles in nineteen minutes with her more modern rapid-firing guns, it will be seen that we have vastly increased the offensive power of the battery in recent ships without providing sufficient endurance. It may be said that there is less necessity for great endurance with rapid-firing guns than with those that fire slowly, because battles may be proportionally shorter; but still, we should get a reasonable endurance, and one and one-half hours is not enough.
In this table, as in the previous one, there is no comparison of the personnel, but simply of the gun power of the different ships. In this comparison there are many surprises and many valuable hints. The armored cruiser New York threw within twenty per cent, as much metal as did the battle-ship Indiana, the former with 8-inch and 4-inch guns, and the latter with 13-inch, 8-inch and 6-inch guns. The Cincinnati and the Raleigh, each with five 5-inch rapid-fire guns and one 6-inch rifle, in broadside, fired three times as much metal as did the Newark, a ship half again as large, having six 6-inch rifles in broadside. This latter fact shows the great gain in adopting rapid-firing batteries, because the penetrating and destructive power of the new 5-inch rapid-fire guns is as great as that of the 6-inch guns of the Newark. The Cincinnati and the Raleigh, therefore, could each do three times as much damage as could the Newark, with the same number of guns.
The comparison of the Indiana and the New York presents the same argument in favor of the rapid-fire guns of medium caliber. The New York, with six 4-inch rapid-fire guns in broadside, threw more metal than did the Indiana's four 8-inch and two 6-inch rifles. And had the New York been supplied with 5-inch rapid-fire guns, which can be fired quite as rapidly as the 4-inch gun, as demonstrated by the Raleigh, she would have fired 11,699 pounds of metal—that is, 600 pounds more than the Indiana fired from all her guns, including those of 13-inch caliber.
Nothing more is needed to demonstrate the value of the 5-inch rapid-fire guns. The cartridge is not so heavy that it cannot be quickly handled, in which it is superior to the 6-inch, and is hardly less manageable than is the 4-inch. It is a happy mean.
In the case of the Columbia the record shows that this ship, with a displacement of nearly 8000 tons, is so deficient in gun power that she can throw only half as much metal as do the Cincinnati and the Raleigh, of 3200 tons.
This is the most striking instance of several in the new Navy, where gun power and battle efficiency have been sacrificed or forgotten.
The study of these valuable tables shows the necessity of returning to the policy that gave victory to Decatur, to Hull and to Farragut—the policy of providing our ships with plenty of ammunition and with batteries that can fire it rapidly and accurately.
The vessels of the North Atlantic Squadron, under Adml. Bunce, engaged in manoeuvres, are at present off Fishers Island, New York. The squadron left New York Sept. 1, consisting of the New York, Texas, Indiana, Raleigh, Maine, Columbia, Massachusetts, and the Newark. The Newark was detached at the light-ship and ordered to proceed to Key West to relieve the Montgomery. When the squadron rounded the eastern end of Block Island, the battle-ship Massachusetts was detached and ordered to proceed to Newport to get her outfit of torpedoes, and rejoin later on. Adml. Bunce ordered landing drills to take place. The orders directed the following general plan to be followed: First day, organization and equipment on board ship to insure compliance with all the requirements of squadron regulations. Afternoon, disposition of the men in boats. Second day, forenoon, company exercises; afternoon, same in extended order on shore. Third day, forenoon, battalion exercises; afternoon, same in extended order. Fourth day, ball cartridge practice; forenoon by company, afternoon by battalion. Fifth day, brigade battle formations. Sixth day, forenoon, outpost duty, advance and rear guards; afternoon, pass in review.
On Sept. 9 the men of the fleet were landed for drill. The battalions were first embarked and manoeuvred in line and columns of boats. The flotilla presented a fine appearance, and the fifty boats were handled with ease by signals. After the landing the different battalions marched to their drill grounds and spent the day, from 9 A. M. till 5 P. M., in practical manoeuvres. Officers and men are reported working hard and enthusiastically.
NEW YORK TIMBER DOCK.
[ARMY AND NAVY JOURNAL.]
The new timber dry dock at New York Navy-yard is now practically finished, and after being inspected by the Government officials will, if found to be up to the specifications, be formally accepted. The dimensions of the dock, which is said to be the largest in the United States, are given as follows: Length on top from head to gate, 670 feet; width, 151 feet on the top and 60 feet 4 inches at the bottom; gate, 108 feet 8 inches on top and 71 feet 6 inches on the bottom. There will be 29 feet of water over the sills, while the gate will be 35 feet 6 inches high. A sea wall 200 feet on either side of the gateway is to be constructed of stone. It is expected the work will be completed and the dock ready for occupancy early in September. The pumping station has been completed for several weeks and, besides the three pumps, with a capacity of 200,000 gallons a minute, the dock can be flooded without their assistance, as it is connected with the basin by two large pipes and one small pipe, and by turning a valve the water will flow into the dock from outside.
SHIPS OF WAR.
[ENGLAND.]
THE ISIS.
On June 27th, at Govan-on-the-Clyde, the new second-class cruiser Isis was launched from the yard of the London and Glasgow Engineering Company. She is the last to take the water of the six cruisers of the Talbot type, which were entrusted for construction to private builders. Her dimensions are as follows: Length, 350 feet; beam, 54 feet; and with a draught of water of 20 feet 6 inches, she has a displacement of 5600 tons. The stem, stern-post, and shaft brackets are of phosphor bronze, as are also the twin propellers. Internally the hull is subdivided transversely and longitudinally by numerous bulkheads, and the vital portions of the vessel are protected by a continuous steel deck, varying in thickness from 3 inches to 1 1/2 inches. In the vicinity of the engine-room additional safety is provided for the propelling machinery by an armored citadel, formed of 5-inch Harveyized steel plates. The armored conning tower, from which the vessel will be manoeuvred in action, is built of the same material, 6 inches thick. Externally the hull is sheathed with teak 3 inches thick, and this will be covered with copper after the vessel has been handed over to the dockyard authorities. For about a third of her entire length amidships teak bilge keels are fitted, and these are cased with brass plates. The propelling machinery, which will be fitted on board by her builders, comprises two sets of triple-expansion engines, in separate compartments, having cylinders of 33 inches, 49 inches, and 74 inches diameter, with a common stroke of 39 inches. Steam is supplied from eight single-ended boilers of the Navy type, at a pressure of 155 lbs. to the square inch. Each boiler has three corrugated steel furnaces, and appliances are fitted as usual to enable the vessel to steam either with forced or natural draught. Under forced draught the estimated speed is 19.5 knots, the engines developing 9500 I. H. P. The armament will comprise five 6-inch guns, so arranged that three may fire in direct line ahead and two direct astern in line with the keel, six 4.7-inch guns, besides nine 12-pounders and a number of smaller guns, all being Q. F. In addition, the hull is pierced for three torpedo-discharge tubes, two submerged and one above water at the stem. The vessel is lighted throughout by electricity. The installation includes three powerful search-lights, and a new multiple flash-light for signaling purposes will be fixed at the masthead. Consequent on the improved methods in the manufacture of steel and the experience gained by its extended use for shipbuilding purposes, the Whitehall authorities have now demanded a higher tensile strength from the manufacturers. Until recently it was obligatory that plates should stand a tensile stress of from 26 to 30 tons per square inch of section. All future plates for Admiralty purposes are, however, to successfully stand a stress of from 30 to 35 tons.
THE ECLIPSE.
[JOURNAL OF THE ROYAL UNITED SERVICE INSTITUTION.]
The new second-class cruiser Eclipse, which was built and engined at Portsmouth, has carried out her official steam trials with satisfactory results. The ship is propelled by two sets of three-crank triple-expansion engines, with cylinders of 33 inches, 49 inches, and 74 inches diameter, by 39 inches stroke. The main bearing frames, piston, cylinder, and slide covers are of cast steel, and the ordinary double eccentric gear is used for actuating the slide valves, the reversing motion being of the all-around design, which alone is now accepted for ships of the Royal Navy. The steam supply for the engines is obtained from eight boilers of the return multitubular type, each boiler being 14 feet 6 inches in diameter and 9 feet 11 1/2 inches in length. There are 24 corrugated furnaces of 3 feet 9 inches diameter, each fitted with bars giving a total grate surface of 630 square feet. With the exception of the two main feed pumps, by Messrs. Weir, of Glasgow, the propelling machinery has been designed and made entirely in Portsmouth Dockyard, and the arrangements generally, having regard to their completeness, accessibility of parts, and simplicity, indicate the ability to steam at full speed as long as her coal capacity will carry the ship without any more risk than is incurred by the Atlantic liners. The normal draught of the ship is a mean of 22 feet 6 inches, but during the trials her draught was only 18 feet 8 inches forward and 22 feet 4 inches aft. The results during the eight hours' run under natural draught were as follows: Steam in boilers 152.7 lbs., and the vacuum 25.7 inches starboard and 26.5 inches port; the revolutions were 135.7, and the collective I. H. P. 8220, or 220 above the contract, while there was an air pressure of only 0.39 inch. After leaving Portsmouth the ship passed to the eastward of the Isle of Wight, and on reaching Portland turned, pursuing an eastward course till Brighton was neared, and then she turned again for Spithead, where she anchored for the night, having maintained a uniform speed of 19.2 knots. The engines worked with remarkable smoothness, the average temperature in the engine-room being 85. The coal consumption per I. H. P. per hour was 2.27 lbs. On the four hours' run, under forced draught, the following results were obtained: Steam in boilers, 155 lbs.; vacuum, 25.7 inches starboard and 26.6 inches port; while the average revolutions were 141.17 starboard and 142.36 port per minute. The starboard engines gave a mean H. P. of 4820, and the port engines of 5033, or a collective power of 9853, being 253 above the stipulated power. The speed as registered by patent log was 20.1 knots. The engine-room and stokehold were so cool during the trial that the two exhaust fans were not required. The trial was regarded as perfectly satisfactory. The vessel also went through her circle trials, answering her helm admirably. During the thirty hours' run which followed, her mean draught was 18 feet 2 inches forward and 22 feet 2 inches aft, and she had 135.6 lbs. of steam in her boilers, with a vacuum of 26.5 inches on both sides. With 115.7 revolutions starboard and 116.3 port, her engines showed 2418 and 2420 H. P. respectively, or a collective H. P. of 4838. There was no air pressure, and the consumption of 1.83 lbs. of coal per I. H. P. per hour she gave a mean speed of 16.8 knots. In view of the fact that the ship at all her trials was drawing much less than her normal sea draught, it cannot be said that the speed obtained was as high as it ought to have been.
THE TERRIBLE.
[ENGINEERING.]
The new first-class cruiser Terrible has arrived at Portsmouth and been placed in the new dock, No. 14, to be completed for sea. During her trials on the Clyde the Terrible, with 100 revolutions, attained a speed of 20 1/2 knots, and with 105 revolutions 21 1/2 knots. At 4.30 on the morning of June 23rd she left Hellensburg for Portsmouth, using only 24 out of her 48 boilers, and two hours after starting, with 70 revolutions, she attained a speed of 15 knots, which she maintained till she arrived at Spithead late on the evening of the 24th. She had fine weather with smooth sea, but an adverse tide for the greater part of the distance, but no difficulty was experienced in keeping a uniform speed, and the Belleville boilers worked very satisfactorily. With all her stores on board the Terrible will have an even keel, drawing 27 feet both fore and aft, but having no stores on board, and having shipped only 500 tons of coal, though her capacity is 3000 tons, she drew only 20 feet 4 inches and 26 feet 4 inches aft when she started, thus giving her an appearance of standing too high out of the water forward. The machinery and boilers gave no trouble of any kind, and the speed would have been better but for the fact that she is at present only wood sheathed and has been in the water for thirteen months, having been launched in May, 1895. Her guns are not yet on board, and her barbettes cannot be completed until the guns are mounted, but the casemates are in position and ready for the auxiliary armament. On the trip to Portsmouth her steering geer answered admirably. The vessel is in a forward condition, and could be prepared for sea in two months, as she has only to be copper sheathed and have her submerged torpedo-tubes fitted.
NEW BATTLE-SHIPS.
[ENGINEERING.]
The Admiralty have given out orders for the construction of five battleships of a new class to be known as the Canopus type. One is to be constructed by the Thames Iron Works and engined by Messrs. Mandalay, Sons, and Field, both of London; a second is to be built and engined by Messrs. Laird, of Birkenhead; a third is to be constructed at the Chatham Dockyard and engined by Messrs. Penn, Greenwich; and the other two are to be laid down at Portsmouth and Devonport respectively. These vessels are to be of 2000 tons less displacement than the Majestic class, our largest battle-ships, one advantage, in addition to less first cost, being that they will be able, owing to less draught, to go through the Suez Canal. Their length is 390 feet and the beam 74 feet, the displacement being 12,950 tons and draught 26 feet. Structurally they will be similar to the Majestic class, but to secure the reduction in displacement certain modifications have had to be made, the most significant being a reduction in the thickness of the Harveyized armor which protects the broadside for the greater part of the length and for some 18 feet of its depth. The new ships will have 6-inch plating instead of the 9-inch in the Majestic, but the armament will be the same, four 12-inch 45-ton guns being mounted en barbette, and these guns by reason of their great length—35.43 calibers—give, with an 850-lb. shot, a muzzle energy of 33,940 foot-tons. There will also be twelve 6-inch quick-firing and 30 smaller guns. The engines are to be of the triple-expansion type, having cylinders 30 inches, 49 inches, and 80 inches in diameter by 51-inch stroke. The power is to be 13,500 indicated horse-power, which will give a speed of 18 1/4 knots, against 17 1/2 knots in the Majestic. This increase in speed is partly due to the adoption of Belleville water-tube boilers, a slight saving in weight per unit of power being utilized to add to the total power. These are the first British battle-ships into which the water-tube boilers have been fitted, but in this case an interesting change has been made in the design largely to secure a greater fuel economy. There will be placed in the uptake over each boiler practically a small boiler to serve as a feed-heater, the feed water passing into the bottom tube in this auxiliary and through the various tubes overflowing into the pipe leading to the main generator. There will be 20 boilers, with about 32,000 square feet of heating surface and 1100 square feet of grate area. The vessels, it is hoped, will be completed by the autumn of 1898.
THE VICTORIOUS.
[ENGINEERING.]
The natural draught trials of the Victorious, first-class battle-ship, which took place on Monday, August 31, proved satisfactory. They extended over eight hours, and the average speed was nearly 17 knots, the contract speed of 16 1/4 knots thus being exceeded. The contract indicated horsepower of 10,000 was also exceeded, and the machinery worked smoothly throughout. The vessel behaved splendidly. The contractors are Messrs. Hawthorn, Leslie & Co., and the engines are of the inverted vertical triple-expansion type (two sets).
The four hours' forced draught trials took place Sept. 2, and were very successful. Results were as follows: Steam in boilers, 147 lbs.; revolutions, 105.35; vacuum, 26.55; I. H. P., 12,210; speed, by log, 18.7 knots; the guaranteed speed was 17 1/2 knots.
THE CAESAR.
[ENGINEERING.]
The first-class battle-ship Caesar, which is one of the nine vessels ordered under the Spencer programme, and the third of the series to be launched or floated at Portsmouth, was floated out of No. 12 dock on Sept. 2. The Caesar may be regarded as an improved Majestic. The chief difference between the two most modern battle-ships is that the Majestic has a fixed loading position, with an auxiliary all-round loading, while the Caesar has no fixed loading position, but has the same auxiliary as the Majestic; thus while the empty gun of the Majestic must come to the fore-and-aft position to load, thereby presenting itself as a target to the enemy should the ship be broadside on, to say nothing of the loss of time if the gun has just been fired on the beam, the Caesar can reload as she fires in any position, owing to the improvement that has been effected in the design of the mounting and supply. The 12-inch wire guns of the Majestic and Caesar have, in fact, the same penetrating power as the 110-ton guns of the Sans Pareil and Benbow. The gun mountings are designed and supplied by Sir John Whitworth & Co., and the machinery has been manufactured by Messrs. Maudslay, Sons, and Field. The principal dimensions of the Caesar are: Length between perpendiculars, 390 feet; extreme breadth, 73 feet; mean draught of water, 27 feet 6 inches; displacement when fully equipped, about 15,000 tons. She will be fitted with twin screws, each driven by an independent set of vertical triple-expansion engines, capable of working up to 6000 indicated horse-power, or a total of 12,000 for the two sets of engines, with a working pressure in the boilers of 150 lbs. to the square inch and an air pressure in the stokeholds equal to 1 inch of water. With this horse-power a speed of 18 knots will be realized. The normal amount of coal to be carried is 900 tons, but provision is made for stowing 2250 tons. The armor, which varies in thickness from 6 inches to 14 inches, consists of steel plates, the outer surface of which has been carburized by the Harvey process, and protection is afforded by this armor to the machinery, guns, and magazines. The Caesar will carry two masts, each having two fighting tops, and each of these will carry three 3-pounder quick-firing guns with the necessary magazines and equipment. A steel derrick, about 61 feet in length, will be fitted on the mainmast for lifting the heavy boats into position on the skid beams, while on the foremast a wood derrick will be fitted for lifting the lighter boats and for coaling purposes. At the top of each lower mast, a distance of nearly 100 feet above the water, a platform will be built carrying a powerful search-light projector, while at the main topmast head, a distance of 170 feet from the water, a semaphore for long-distance signaling will be fitted. Including four steam boats, the Caesar will carry no fewer than 18 small craft, three of the steam boats being capable of acting independently of the ship for the purposes of torpedo attack, and fitted for discharging 14-inch Whitehead torpedoes. One of the boats will also be fitted for carrying the spar torpedo. Four of the light boats will be carried in davits, to enable them to be rapidly lowered when required to act as lifeboats. The armament of the Caesar is similar to that of the other ships which have been fully described in Engineering. Six search-light projectors, worked by three dynamos, each of 600 amperes, will be carried, and to complete the protection against torpedo attack the vessel will be fitted with the latest system of net defense.
TORPEDO-BOAT DESTROYERS.
THE STAR.
H. M. torpedo-boat destroyer Star was launched recently from the Howdon yard of the Palmer Shipbuilding and Iron Company, Limited. The vessel is the first of eight of the same class which are being built by the Yarrow firm for Her Majesty's Navy. Her dimensions are: Length, 215 feet; breadth, 20 feet 9 inches; and the displacement is about 300 tons. Her armament consists of one 12-pounder quick-firing gun forward on the conning tower, with four 6-pounder quick-firing guns on the broadside, and one 6-pounder on a platform aft. There are also two revolving torpedo-tubes on deck, arranged to fire on either broadside. The builders have guaranteed a speed of 30 knots, and the machinery, which has been designed by them, consists of two sets of triple-expansion engines, steam being supplied by four of Reed's patent water-tube boilers.
THE SWORDFISH.
The torpedo-destroyer Swordfish made her official trial on July 9 off the mouth of the Thames. The vessel is 200 feet long by 19 feet beam. She developed 4359 I. H. P., with average steam pressure of 194 lbs., and 394 revolutions per minute, attaining an average speed of 26.8 knots.
THE ELECTRA.
Messrs. James and George Thomson, Limited, launched on July 14th from their yard at Clydebank the torpedo-boat destroyer Electra, which they have designed and built to the order of the British Government. This is a sister ship to the Brazen, launched by the same company some days ago, and is the second of four vessels ordered at the end of last year. These vessels are to attain a speed of 30 knots.
THE HARDY.
The new torpedo-boat destroyer Hardy, built by Messrs. Doxford & Sons, of Sunderland, has also completed her official full-power trials on the measured mile off the Maplin Sands. The speed stipulated for by the Admiralty is 26 knots, and the Hardy easily achieved a mean rate of 26.8 knots for six runs over the measured mile, and a mean speed of 26.514 knots for three hours' continuous steaming. The mean steam pressure in the boilers was 189 lbs. per square inch, and the mean revolutions were 380 per minute. The average I. H. P. developed was 4184.
THE POWERFUL.
The first-class cruiser Powerful, built and engined by the Naval Construction and Armaments Company, arrived at Portsmouth on July 17th and was taken into the repairing basin in readiness to be docked. Starting from the Devonshire dock at Barry at four o'clock on Monday morning, the 13th inst., in the presence of some thousands of spectators, the great cruiser was berthed in the Ramsden Dock till the tide served, and at noon she left for a run in the Irish Sea. She was berthed for the night at Liverpool, where, on Tuesday, the ship brought up her coal supply to 1200 tons and took on board fresh water. On Wednesday she had an unofficial trial of her machinery, slowly working, up to 95 revolutions, at which, in a run of six hours, she maintained a mean speed of 19 knots, with all her 48 boilers in use. Having landed some of the officials, the ship left Liverpool at 8.30 on Wednesday evening, using at first only 16 boilers, and, with 60 revolutions, she gained a speed of 12 or 13 knots; but on Thursday morning eight more boilers were lighted up and the revolutions increased to 75, when the speed slightly exceeded 15 knots.
REMOVAL OF TORPEDO TUBES.
The Admiralty have ordered the stern torpedo-tubes to be taken out of all ships of the Royal Sovereign class, and these vessels will now carry only the submerged tubes. There are two very substantial reasons for this course. Experiments have been made which have demonstrated the possibility of hitting the whiskers of a torpedo by means of quick-firing guns while the weapon is in the tube, and thus hoisting the engineer with his own petard. Then, says the Naval and Military Record, it has been found on the China station that where the stern tube is reasonably near the water-line, the seas in rough weather fill the tube, and if the torpedo is there, collapse the balance chamber. The trials of the Eclipse were especially directed to elucidate this point, but though no accident occurred in that cruiser, owing to her tube being well out of the water, an immunity from accident is not guaranteed to ships less favorably constructed. Hence the necessity that has arisen for removing the tubes.
TEST OF HARVEYIZED PLATE.
An experimental Harveyized armor plate, produced by Messrs. John Brown & Co., Atlas Steel and Iron Works, Sheffield, was tested on board H. M. S. Nettle with most satisfactory results. The plate was 8 feet by 6 feet by 6 inches, and five Holtzer projectiles, weighing about 100 lbs. each, were fired at it, with the full charge of E. X. E. powder, giving a velocity of 1960 foot-seconds. All the shots were broken up, fragments of two only entering into the wood backing very slightly. In spite of the extraordinary resistance thus given, the plate proved so tough that only one slight hair-track was perceptible after the firing of the fifth shot. The trial was witnessed by Sir William White, K. C. B., Captain Jeffreys (H. M. S. Excellent), Captain May (of the Ordnance Department), and other officials.
[FRANCE.]
D'ENTRECASTEAUX.
[ENGINEERING.]
The D’Entrecasteaux, first-class cruiser, launched at La Seyne on June 11 from the yard of the Societé de la Méditerranée, is, with the exception of the Guichen, "commerce destroyer," the largest unarmored vessel in the French Navy. The following are her principal dimensions: Displacement, 8114 metric tons; length, 393 feet 8 inches; beam, 58 feet 6 inches; draught, 25 feet 9 inches. Her armament will consist of two 9.4-inch guns in closed turrets (2.7-inch plating), severally fore and aft, and twelve 5.5-inch and twelve 1.8-inch quick-firers, besides six torpedo-tubes, of which two are submerged. Cylindrical double-ended boilers and two vertical triple-expansion engines developing 13,500 horse-power are to give a speed of 19 knots, and, with the normal coal supply of 650 tons, the range will be 5500 miles at 10 knots and 900 miles at full speed. The cruiser will have a complement of 21 officers and 500 men. She is built of steel and sheathed for foreign service, and her cost is stated to be £667,740. The designs are by M. Lagane, who prepared the plans for the Jauréguiberry. The vessel was laid down in 1894, and is to be delivered, by the contract, at the close of 1897.
THE CHARLES MARTEL.
[JOURNAL OF THE ROYAL UNITED SERVICE INSTITUTION.)
The new first-class battle-ship Charles Martel had a satisfactory preliminary trial under 11,000 I. H. P., with the following results: I. H. P. realized, 10,990; revolutions of engines, 89; consumption of coal per H. P. per hour, 1.03 kilogramme; consumption per square meter of grate surface, 120 kilogrammes; speed, 16.8 knots. The new second-class cruiser Descartes has been continuing her official trials; during a run of 24 hours, at full speed under natural draught, a mean speed of 17.5 knots was maintained; the engines developed 5802 I. H. P. making 118.5 revolutions; coal consumption per H. P. per hour, 0.753 kilogramme; and consumption per square meter of grate surface, 70 kilogrammes; during the full-speed trial, under forced draught, the engines developed 8870 I. H. P., making 135 revolutions; coal consumption per H. P. per hour, 0.965 kilogramme; consumption per square meter of grate surface, 135 kilogrammes; and the mean speed, 19.5 knots.
THE EXPLOSION ON BOARD THE AMIRAL DUPERRÉ.
On May 14 an explosion occurred on board the Amiral Duperré, flagship of the French Mediterranean Reserve Squadron. It was discovered that a cartridge for the 13.3-inch gun had exploded in the passage leading to one of the magazines, which at the time contained nearly five tons of powder, so it is evident that the escape from a terrible disaster must have been very narrow. It is stated that the explosion was caused by the spontaneous decomposition of the powder in the cartridge due to the excessive temperature in the passage, which was more than 104 Fahr., a heat sufficient to cause the powder to decompose and give off inflammable gases. In consequence of this accident, a careful examination of the magazines of the Hoche, the new flagship of the squadron of the North, has been made, and the temperature of those for the 27-cm. and 14-cm. guns, which are in the center of the ship, being found very high, at the request of the admiral the ammunition has been removed and temporarily placed in the magazines on shore.
EXPERIMENTS WITH MELINITE SHELLS.
The experiments with melinite shells, which have been carried on against the obsolete ironclad La Galissonniere, have concluded, and the ship has been towed back to Toulon. The results of the experiments have not been divulged, but it is stated that six shells, charged with 39.6 lbs. of melinite, were fired from a 7.4-inch gun, that they penetrated 2.9 inches of Harveyized steel and burst on board, doing an enormous amount of damage. Up to the present, nobody but a few officials and the members of the committee have been allowed to examine the damage done to the ship.
[ITALY.]
ITALIAN WAR-SHIP BUILDING NOTES.
Three new first-class battle-ships of the Re Umberto type, but with somewhat less weight of armor and a larger secondary battery of Q. F. guns, are shortly to be commenced—one at Spezia, one at Castellamare, and the third at the Ansaldo yard at Sampierdarena, Leghorn. The ships under natural draught are to have a speed of 20 knots, and 22 knots under forced draught. The engines and boilers are to be manufactured by the firms of Ansaldo, Odero, and Guppy, respectively.
The Minister of Marine has ordered from the Odero firm at Sestri Ponente a new torpilleur-de-haute-mer of a special type. She is to be 152 feet in length, 18 feet beam, and with a draught of 3 feet 4 inches will have a displacement of 135 tons; the engines are to develop 2500 I. H. P. and to give a speed of 25 knots.
THE MARCO POLO.
The new armored cruiser Marco Polo has lately completed her final acceptance trials at Naples, and will shortly reinforce one of the active service squadrons.
She was built in the Royal Dockyard at Castellamare di Stabia, and engined by G. Ansaldo & Co., of Sampierdarena. Her dimensions are as follows: Length between perpendiculars, 327 feet; beam, 48 feet; and with a draught of just over 19 feet, she has a displacement of 4600 tons. The engines were required to develop 6000 I. H. P. with natural draught, and 10,000 I. H. P. with forced draught. There are two independent sets of engines and shafting in separate compartments, and two separate boiler-rooms, one before and one abaft the engine-rooms, each containing two cylindrical double-fronted boilers. The weight of the propelling machinery complete with all accessories, water in the boilers and condensers, etc., is about 800 tons. Forced draught is obtained by ventilators on the closed stokehold system. Each engine has four cylinders, one high pressure, one low pressure, and two other, also low pressure, of 37 inches, 57 inches, and 62 inches diameter respectively, and a stroke of 30 inches. The high pressure cylinders only are fitted with cylindrical slide valves; the supporting columns rest upon girders forming part of the structure of the ship. The propellers are four-bladed, of manganese bronze, 14 feet diameter, with a mean pitch of about 15 feet. The condensers have a cooling surface of 1100 square meters each, the auxiliary condensers 70 square meters. A small independent engine is provided for working the circulating and air pumps; the latter, two in number, are single acting; the circulating pumps are capable of drawing from the bilge and discharging overboard 700 tons of water per hour.
The ship is protected by an armor belt of 4-inch steel, from the upper deck to about 3 feet 3 inches below the water-line for about two-thirds of her length, connected at the ends by armored athwartship bulkheads of the same thickness of steel. There is also a 2.5-inch armor deck extending the whole length of the ship. She is provided with a double bottom, cellular construction between the protective and lower decks, and longitudinal cofferdams fitted with cellulose.
The armament consists of six 152-mm. (6-inch) Q. F. guns, ten 4.7-inch Q. F. guns, together with a large number of Q. F. guns of smaller caliber. There are also five torpedo discharges, one bow submerged and four above water broadside. The official trials for coal consumption of 10 hours' duration, as required by the contract, were carried out at Naples in December, 1895. With all boilers alight and with steam pressure varying between 135 and 150 lbs., the revolutions were 125 to 126, and the I. H. P. 7150, with a coal consumption of 1.87 lbs. per I. H. P. per hour. The mean speed for the whole duration of the trial was about 17 knots.
In the subsequent forced-draught trial of three hours, in the month of January last, the power developed was about 10,700 I. H. P., with 140 revolutions, and a coal consumption per I. H. P. of 2.1 lbs. The air pressure by the water barometer for the forced draught was from 2 to 2 1/2 inches. The speed on this trial was 19 knots, but it would certainly have been much higher if the ship had been docked and her bottom cleaned, as she had been lying in the basin for some months.
[GERMANY.]
KAISER FRIEDRICH III.
[JOURNAL OF THE ROYAL UNITED SERVICE INSTITUTION.]
On the 1st of July, at Wilhelmshaven, the new first-class battle-ship Ersatz Preussen, but now the Kaiser Friedrich III, was successfully launched in the presence of the Kaiser.
The dimensions of the ship are as follows: Length between perpendiculars, 373 feet 9 inches; beam, 67 feet; and the mean draught of 25 feet 8 inches, she has a displacement of 11,130 tons. Protection is afforded by a water-line belt of hardened steel, extending from the ram aft for four-fifths of the vessel's length, with a maximum thickness of 12 inches tapering to 6 inches; there is an armored deck on top of the belt 2.5 inches, and a second armored under-water deck, extending from termination of belt to stern, 3 inches thick. The armament is composed of 24-cm. (9.4-inch) guns disposed in two turrets, one forward and one aft, protected by armor of 10-inch hardened steel; a secondary battery of eighteen 15-cm. (5.9-inch) Q. F. guns, six of which are carried in 6-inch armored turrets, and the remaining twelve in 6-inch armored single casemates; twelve 8.8-cm. (3.3-inch) Q. F. guns on the superstructure deck, protected by shields; and twenty small Q. F. guns distributed between the tops and various parts of the ship. There are six torpedo-tubes for 18-inch torpedoes, one in the stem, one in the stern, and two on each broadside. The ship will have three screws, and the engines are to develop 13,000 I. H. P., giving a speed at load draught of 18 knots. The boilers will be partly cylindrical and part water-tube, while the coal capacity at load draught will be 650 tons. There will be two military masts, and the crew will number 655 officers and men.
[RUSSIA.]
The activity of Russia in developing Vladivostock since the war between Japan and China has led to a great demand for Chinese labor at that port. It is estimated that during the present season fully 10,000 Chinese coolies have been shipped from Shanghai and other ports to work on the fortifications, the great dry docks, and the railway which is being built eastward to meet the trans-Siberian overland road. The fortifications are said to be more powerful than those which the Chinese built at Port Arthur, although for seven months in the year ice effectually bars entrance to the harbor. The Russian military officials are said to have received stringent orders against any inspection of the harbor or city fortifications, and they even go to the length of forbidding tourists or any residents from ascending the hills, from which a good general idea may be secured of the works and of the depots for ammunition. For years it has been the custom of military and diplomatic officials and business men to hunt and fish with perfect freedom near the city; but now shooting and fishing permits are difficult to obtain, while arrest and fine await any sportsman who fails to get the necessary permission from the commandant.
Orders have been given, says the St. Petersburgskiya Viedomosti, to the Admiralty works at Ishora to build two "destroyers" of the Sokol type. The Normand torpedo-boat Pernoff, which was intended for service with the Mediterranean squadron, will, according to the Army and Navy Gazette, be detained to serve as a model at the same works. The torpedo-boat Pakerort will go in its stead.
[SPAIN.]
WAR-SHIP BUILDING NOTES.
The Spanish Minister of Marine has applied to the Spanish Council of Ministers for special credits to the amount of £920,000 for increasing the Spanish fleet and extending the Spanish arsenals and naval establishments. The special credits include an item of £80,000 for the new first-class cruiser Reina Regente. The Spanish Minister of Marine further contemplates the construction of an ironclad to have a displacement of 11,000 tons, and to cost £880,000; two cruisers of 6800 tons each, and two torpedo-boat destroyers. The Minister further proposes to equip the Pelayo with rapid-firing guns, and to convert the Numancia frigate into a floating battery.
The Spanish Government has closed the contract for the purchase of two cruisers now building in the Ansaldo works, Leghorn, to be named the Cristobol Colon and Pedro d'Aragona, and to cost from 17 to 18 million francs.
It has also been decided to purchase in Scotland an ironclad of 10,500 tons, a cruiser of 6500 tons, and two torpedo-catchers. A cruiser of 1500 tons, having a speed of 20 knots, is also to be built in England. According to the contract the vessels are to be built in 18 months.
In view of the present activity displayed by the Naval Department, the following particulars of the various vessels built and being built on the home station may prove interesting.
The Pelayo, ironclad, at present at Cadiz, carries four big guns and about twelve of smaller caliber, with the usual number of Nordenfelt, Hotchkiss and other quick-firing pieces. She is employed as the flagship of Rear Admiral Requera, and is capable of doing fifteen knots on a push.
The Vizcaya, also in Cadiz, is a belted cruiser, 7000 tons, and carries two 28-cm. guns in protected turrets and ten of 14-cm., with also a number of quick-firing Nordenfelts. Her speed is eighteen knots natural draught and twenty forced draught.
The Maria Teresa and Oquendo, two sister ships to the Vizcaya, are in commission at Barcelona.
There are three torpedo-boats at Carracas (near Cadiz) and other three at Cartagena. Also at Cartagena, Carracas and Ferrol are a few obsolete vessels. Two or three of these might, on an emergency, be put in commission, but this is scarcely likely, owing to their having old-fashioned boilers and machinery.
Before the 18th of September the Princessa de Asturias, it is expected, will be launched. Her hull is of steel; tonnage, 7000; draught, 6.58. She has an armor belt of 300 mm., tower, 300, and protective deck, 50; will carry two guns of 240 mm. Hontorio; eight of 57 Nordenfelt; eight of 37 Hotchkiss; two mitrailleuses of 11 Nordenfelt, and two of 70 Hontorio, besides eight torpedo-tubes. Indicated horse-power, 15,000; speed, 20.25; coal capacity, 1200 tons, sufficient for 9700 miles at ten miles per hour. Crew complement, 497 men.
In the arsenal at Ferrol, nearly ready for launching, is the Cardenal Cisneros, belted cruiser, 9000 tons.
The Catalina is on the stocks at Cartagena. These two vessels are sister ships to the Princessa de Asturias, described above.
In construction also at Ferrol, but in a private yard, are three gunboats of 600 tons each.
Great activity is being at present observed in the construction of the Carlos V, 900 men being employed. The government is desirous of having her ready for sea in as short a time as possible.
The Lepanto, a sister ship to the unfortunate Reina Regente and Alfonso XIII, with a few modifications, is nearing completion at Cartagena, and will probably be ready for her sea trials about March. The Alfonso XIII has undergone some preliminary trials, but is still at Ferrol. The boilers of the torpedo-boat destroyer Distructor, which was built some years ago by Messrs. Thompson, of Glasgow, are in a bad state of repair.
[BRAZIL.]
THE BARROZO.
Sir W. G. Armstrong & Co. (Limited) launched from the Elswick shipyard, Newcastle-on-Tyne, on Tuesday, August 25, the Barrozo, a cruiser built to the order of the Brazilian Government. The Barrozo is built of steel, her under-water portions being sheathed with wood and coppered. Her principal dimensions are: Length, 330 feet; breadth, 43 feet 9 inches; draught, 16 feet 10 inches; and displacement, 3450 tons. She is protected throughout the whole of her length by a curved steel armor deck. This deck completely covers all the machinery, magazines, and steering gear, and additional protection is afforded by the reserve coal bunkers, which are carried along the vessel's side to a height of about 6 feet above the water-line. With full bunkers the vessel will be able to traverse a distance of about 8000 knots at a moderate speed. The vessel is fitted with twin screws and machinery of 7500 indicated horse-power. She is expected to attain a speed of 20 knots. The Barrozo will be provided with guns of Elswick pattern, the armament comprising six 6-inch quick-firers of 50 calibers in length, four 4.7-inch quick-firers of 50 calibers, ten 6-pounder and four 1-pounder Nordenfelts, four Maxim guns, and two field guns. She will also have three torpedo-tubes. The six 6-inch guns are arranged to fire three ahead and three astern.
SHIPS BUILDING.
There are under construction for the Government at present the following ships: In France, two small battle-ships; in England, three protected cruisers; in Germany, three torpedo-cruisers; and in the dockyard at Rio, two monitors for river service. It is further contemplated to add three more cruisers, the orders for which are expected to be placed in Italy.
The three torpedo-cruisers are being built in the Germania yard at Kiel, and the first of them, the Garamuru, was launched in April last. Their dimensions are as follows: Length, 260 feet; beam, 31 feet; and with a mean draught of to feet 3 inches the displacement will be 1030 tons. The engines are to develop 6000 I. H. P., giving a speed of 23 knots. The armament will consist of two 105-mm. (4-inch) guns, six 57-mm. (2 1/2-inch), and four 37-mm. (1.5-inch) guns, all Q. F., with three torpedo-discharges, one in the stem and one on each beam. A small twin-screw gunboat is also being constructed by Messrs. Yarrow.
[CHILI]
THE ALMIRANTE SIMPSON.
The torpedo-gunboat Almirante Simpson, built and engined by Messrs. Laird Brothers, Birkenhead, for the Chilian Government, was taken by them to the Clyde for her official trials on July 23rd. The runs were made in accordance with the Admiralty conditions on the measured mile at Skelmorlie, with an average of 21 1/2 knots on six runs on the measured mile, and a mean speed for three hours' running of 21 1/4 knots, the contract speed being 21 knots. On the natural-draught trial of six hours' duration a mean speed of 17 3/4 knots was obtained with 1/2-inch air pressure, being 3/4 knot in excess of contract, the coal consumption in both cases being very light. The vessel is similar to the Almirante Lynch and Almirante Conde11, built by the same firm for the Chilian Government in 1890, and Her Majesty's ships Onyx and Renard, built in 1893. Her length is 240 feet, beam 27 feet 6 inches, and she is built of steel. The thickness of the side plating abreast the machinery is increased to afford additional protection. She has a topgallant forecastle and half-poop which give accommodation for officers and crew. The builders have also supplied and fitted the armament, which consists of one bow and two broadside 18-inch torpedo-tubes, two 4.7-inch quick-firing guns of Armstrong's most modern type, four 3-pounder quick-firing guns, and two rifle caliber machine guns by Maxim-Nordenfelt. The machinery consists of two sets of triple-expansion engines supplied with steam at 200 lbs. pressure from four water-tube boilers of the modified Normand type, first introduced by the builders, with extra large evaporators and distillers. This vessel has been rapidly constructed, the order having only been placed in September of last year.
The Chilian Government has ordered from the firm of Ansaldo and Co., of Sestri Ponente, Leghorn, an armored cruiser similar in type to the Garibaldi, which, built originally for the Italian Government, has lately been sold to the Argentine Government. There is considerable jubilation felt in Italy at the increasing number of war vessels which are being constructed for foreign governments in Italian yards. The Guardia Marina Riquelme, fourth and last of the 30-knot torpedo-boat destroyers, building by Messrs. Laird for the Government, was launched at Birkenhead, June 20th.
[ARGENTINE.]
THE SANTA FÉ.
[ENGINEER.]
The Santa Fé is the first of four destroyers ordered by the Argentine Government. The names of the remaining three are Corrientes, Misiones, and Entre Rios. They are 190 feet in length by 19 feet 6 inches beam, and one special feature in which they differ from similar vessels in the British Navy is that the machinery space is partially protected by 1/2-inch armor. This partial protection with tough steel plates extends on each side and on the deck throughout that portion of the vessel occupied by the machinery and by the men who work it. In spite of this extra weight of armor, the speed of the Santa Fé, which was recently tried on a three hours' run, was found to be 26.7 knots, carrying a load of 35 tons with only 1 1/4 inches air pressure in the stokehold. The armament of the Santa Fé consists of two deck torpedo-tubes, and one bow tube of the Whitehead pattern, also one 14-lb. Maxim-Nordenfelt gun, placed in an elevated position on the conning tower forward; two 6-pounders are placed amidships, and one 6-pounder at the stern; while two Maxims are placed on either side of the conning tower on deck. The engine-room contains twin-screw engines of 4000 horse-power, besides many other auxiliary engines.
The steam is supplied by six of Yarrow's patent straight-tube water-tube boilers, four being placed in the main and two in the forward stokehold. These stokeholds are kept cool and supplied with air by forced draught produced by two brass fans, revolving in a horizontal plane, close below the deck. The boilers are each encased between diaphragm plates, so that in case any boiler is damaged by shot the influx of steam would be confined to that portion of the vessel occupied by the boiler so injured, and would not pass into the stokehold. This has been proved, by actual experience, to be an important method of protection to the stokers in case of a boiler being struck by the enemy's shot. It may, in passing, be mentioned that in the Santa Fé there are no less than between five and six miles of tubing in the boilers, every inch of which can be readily examined and cleaned. The deck accommodation of the Santa Fé is commodious, and the fitting up for the six officers and forty-four men shows that, as far as possible, the comfort of "those who go down to the sea in ships" has not altogether been forgotten.
We now come to the automatic boiler feed. It has come to be understood that if water-tube boilers are to be worked in comfort there must be some form of automatic feed. The demand for steam is so constantly changing, and the quantity of water at any time in the boiler is so small, that incessant vigilance is necessary, on the one hand, to prevent the boiler from being filled up, with the prospect of drowning the main engines and breaking them down, or, on the other hand, of stinting the feed, with the risk of burning the tubes. The system adopted by Mr. Yarrow is the invention of Mr. Mariner, and is very novel and peculiar. It consists, in one word, in feeding each boiler separately by a Worthington donkey pump and placing the mouth of the steam pipe for supplying the donkey close to the water level of the boiler. If the water rises too high, it will enter the donkey steam pipe and choke the cylinder with water. Then the donkey will almost stop. If the water level falls, then the donkey will work fast and pump the level up again. The accompanying sketch will make the arrangement clear. The steam pipe is placed between two perforated deflecting plates as shown, in order to give it "solid" water to deal with. The level of the pipe is adjustable from outside by means of a cock joint. It might be imagined that this would cause much pounding and thrashing, but personal inspection on Saturday proved that the Worthington pumps work quite quietly. If the boiler is too full of water the pump still works slowly and extracts from the boiler the surplus water to the extent of the difference of the capacity of the steam and pump cylinders respectively, until the level in the boiler is corrected. Thus it will be seen that with this system not only is the water, if low, immediately raised to its proper level, but if too high, it automatically falls. The simplicity of this arrangement, as compared with other systems of automatically regulating the feed, is evident, and it may be observed that during the three hours' full-speed official trial of the Santa Fé the feeding arrangements were never touched or in any way adjusted or interfered with. The heat in the exhaust steam or water passing from the pumping engines and returned to the condenser is utilized in raising the temperature of the feed, so that no heat is actually lost in adopting this combination. Whether it would work equally well with other forms of pumping engines we are not prepared to say, but the Worthington pump seems to be ready to meet every possible variety of demand. The invention has been tried for some time in small torpedo-boats, and reflects much credit on Mr. Mariner.
The success of the Yarrow boilers has now been placed beyond controversy. In connection with this success we may say that it is the desire of Mr. Yarrow that it should be known that much credit is due to Mr. Crush, who is the indefatigable head of the boiler department at Poplar. Mr. Mariner, inventor of the automatic feeder, takes an active part in the management of the engineering department at Poplar, a highly responsible post, thoroughly well calculated to bring into play all the qualities which go to make a first-rate engineer.
[JAPAN.]
[ARMY AND NAVY JOURNAL.]
Bids were opened by an Imperial Board at the Japanese Legation in Washington for the construction of two high-class cruisers for the Japanese Navy. The bids were submitted by the Cramps and the Union Iron Works. America is thus launched into the shipbuilding competition of the world. The Japanese Legation, in accordance with instructions from Tokio, issued invitations to the firms mentioned some weeks ago to submit plans, specifications and proposals for two first-class cruisers of the following general dimensions: Displacement, 4700 tons; length, 370 feet; beam, 48 feet; beam draft, 17 feet 6 inches; horse-power, 15,000; speed, under forced draught, 22 1/2 knots; speed, under natural draught, 20 1/2 knots. The general type of the vessels specified is that of the Yoshino, one of the latest additions to the Japanese Navy. The plans submitted by the firms are complete and embody all the latest developments in naval construction. The bids were opened in the presence of the Japanese Minister, Comdr. Miyaoka, the naval attaché of the Legation, Naval Constrs. S. Sakurai and S. Takakura, and Messrs. Charles and Edward Cramp. The amounts of the bids are kept secret. The board will consider them and the plans and will forward them with recommendations to Tokio for the action of the Government. The Japanese Legation in Paris also opened bids for the construction of one cruiser of the same class as above. These bids will also be sent to Tokio with recommendations. The impression prevails that the Japanese Government will accept the American bids in case they are not too much greater than those of the French shipbuilders. It is believed in naval circles that one of the ships will be built at Cramp's and the other at the Union Iron Works.
[CHINA.]
Viceroy Li Hung Chang ordered three cruisers from the Vulcan Works in Stettin. They are to have the following dimensions: Length at waterline, 328 feet; beam, 41 feet; draught, 16 feet. The draught is made small on account of the shoal waters about the Chinese coast in the neighborhood of Tientsin. Displacement to be 2950 tons. The two engines of 7500 indicated horse-power to give a speed of 19 1/2 knots. The vessels, protected by protective decks, will be armed with batteries of three 5.9-inch, eight 4-inch, six 1.5-inch guns, six Maxims and one 2.4-inch boat gun. There will be one submerged bow torpedo-tube and two above-water broadside tubes. The first of the cruisers to be ready in 15 months, the others in 18 months' time.