Professional Notes

TESTS OF ARMOR-PLATES FOR THE JAPANESE BATTLE-SHIP ASAHI.

Messrs. John Brown and Co., Limited, of Sheffield, who are making the armor for the Imperial Japanese battle-ship Asahi, now building on the Clyde by the Clydebank Engineering and Shipbuilding Company, Limited, submitted for firing test on December 2nd last a piece cut from one of that ship’s partly finished belt plates, which had been selected for the purpose by the Japanese authorities, and the admirable results got are stated.

Doubts have sometimes been cast upon the severity of armor plate trials made in England, on the ground that Holtzer shot are usually employed; that Holtzer’s process of manufacture is an old one; and that the Americans in particular have so improved upon it that shot made by their processes are far more formidable, and so confer more credit on the plate that succeeds in defeating them. It is therefore highly satisfactory to have these doubts proved groundless by the behavior of the plate whose trial we are reporting, which achieved the very marked success shown after the attack of three projectiles made on the most highly vaunted American process—that known as “Wheeler-Sterling.” The following are the particulars of the plate:

All the projectiles were completely shattered, and that the injury sustained by the plate was confined to the usual splintering of its face round the points of impact, and a few superficial hair cracks in the face so fine as to be almost invisible. No cracks whatever beyond these could be found in any part, and the attack left no mark on the back except the three smooth bulges, of which the most prominent measured 1% in. in height. The Japanese Government was represented at the trial by Admiral Matsunaga, Captain Mukoyama (Naval Attache), and. Constructor Captain Kondo, and the highest approval was expressed of the excellence of the result.—Engineering.

THE IDEAL SMOKELESS POWDER.

Great as are the advantages of the best forms of nitroglycerine and guncotton smokeless powder, there is not one of them that can be called an ideal powder. They all suffer from an inherent and ineradicable defect, due to the presence of the nitroglycerine and the fact that its explosive qualities are affected by changes of temperature. The best of these powders might be considered ideal explosives, provided they were always used at exactly the right temperature; but they never or rarely ever are.

When it is stated that 19.5 pounds of cordite fired behind a too-pound projectile in a 50-caliber 6-inch gun will produce a muzzle velocity of 2642 feet a second, the statement is not altogether complete; since one of the elements effecting these results has been omitted—or rather, it is supposed to be understood. Strictly speaking, these results can only be obtained if the powder at the moment of firing is at the normal temperature of the atmosphere. If its temperature is lower, as it would be in the Arctic regions, the velocity will be lower, and if it should be higher, as during an engagement in the tropics, the velocity will be higher. Now between these extremes of cold and heat there will be a difference of velocity which will interfere with the accuracy of the gun; for the sights are adjusted for the velocities due to the powder when fired at normal temperatures.

The pressures, moreover, are even more liable to change than the velocities. It frequently happens that a gun becomes quite hot from firing or from being exposed to the rays of the sun. While in this heated condition a charge may be inserted and, for some reason, allowed to remain for some length of time in the chamber before being fired. The heat of the gun is imparted to the powder, and in this heated condition it is liable to produce abnormally high pressures, and may even detonate and destroy the weapon. It is a fact that in some makes of machine guns serious accidents have resulted from leaving the piece loaded for a few minutes when the gun was overheated.

These troubles are entirely due to the nitroglycerine, and they are inseparable from any powders that include this powerful agent as one of the constituents.

For these reasons several of the European nations have always opposed the use of nitroglycerine in any form, and a vast amount of experimental work has been done in the hope of producing a smokeless powder that should contain none of this explosive. We arc reliably informed that a certain Austrian chemist, who is considered to be the greatest European expert on high explosives, has at last produced a smokeless powder which is entirely free from the defects alluded to and is as safe and reliable as the old black powder. It contains no nitroglycerine and it is affected very little by overheating. It is not only very effective, but it can be manufactured much more cheaply than smokeless powder of the ordinary type.

Our informant, who is perhaps the most noted expert in rapid-fire weapons in Europe, states that the discovery has produced a sensation in naval and military circles, and that great expectations are entertained regarding the new explosive, regarding which particulars will be made public early in the year.—Scientific American.

VICKERS’ 12-IN. GUN.

We describe the new breech mechanism of the 12-in. breechloading gun designed and manufactured by Messrs. Vickers, Sons, and Maxim, Limited, and now adopted also as the standard weapon by the Woolwich authorities. We have in previous volumes fully described the gun and its manufacture, and it is only necessary here to deal with the new mechanism which may be fitted to the 12-in., 10-in., and 9.2-in. gun, and may be fitted with the necessary gear to enable it to be worked by hydraulic or other power; it is applicable to any gun of smaller or larger calibre, and is suitable for either right or left-hand guns. The mechanism is so arranged that by turning the handwheel the breech plug is first rotated and unlocked, and then swung out of the breech of the gun. The unlocking of the breech plug is effected by means of what is commonly known as a toggle joint, the longer arm or link of which has one end fitted on a pin on the face of the breech plug, and the other end is fitted by a pivot joint to the shorter arm or crank mounted in a recess in the carrier on a pivot parallel with the axis of the gun, both the link and the crank thus working in a plane parallel to the face of the breech. Round the boss of the crank are formed “skew gear” teeth, engaging into similar teeth formed partly round the boss of an intermediate quadrant pinion, which is also mounted in the carrier, but on a vertical pivot. This intermediate quadrant pinion has also formed partly round the boss ordinary spur teeth, which engage with similar teeth on an actuating quadrant pinion fixed on the hinge bolt of the carrier. The hinge bolt, together with the actuating pinion, are revolved by means of a worm and a wormwheel, which are in turn actuated by a handwheel suitably mounted at the breech of the gun.

To open the breech the handwheel is rotated, and thus by means of the wormwheel, the actuating pinion causes the intermediate quadrant and crank to turn, thus rotating the breech plug until it becomes unlocked. By continued turning of the handwheel, the carrier with the breech plug is swung out clear of the breech of the gun. The ordinary retaining catch is employed for holding the plug in position when out of the gun. The opposite action takes place on closing the breech. The gun is arranged for firing by electric or percussion tubes, and its action is similar to that of the 6-in. quick-firing gun. A cam in the crank, acting upon the firing gear slide during the first turning of the handwheel, when unlocking the breech, makes the gun absolutely safe before the breech-plug commences to unscrew, and by the continued movement of the crank-cam, the empty tube or primer is automatically ejected.—Engineering.

MASONRY VERSUS WOODEN DRY DOCKS.

There is a growing conviction among naval men that the United States should cease to build wooden dry docks and in future construct all of its docks of masonry. The principal argument in favor of wooden structures is, or used to be, the smaller first cost. While a timber dock could be built for from $400,000 to $600,000 according to its size, a similar masonry structure used to cost from two to three million dollars. This of course was an extravagant figure, but seems to have been unavoidable under the plan of periodical appropriations by Congress, which caused the work to extend over long periods with much consequent waste of time and money.

The recent bidding for a stone dry dock at Boston brought out the welcome fact that a masonry structure can be built for a moderate increase of cost over one of timber. The cost of the dock will be about $1,000,000 whereas the timber dry dock (known as No. 3) at the Brooklyn navy yard cost between $600,000 and $700,000, and in the two years of its existence it has cost for repairs $171,000.

Prof. W. L. Cathcart, of Columbia University, in a paper on the subject read before the American Society of Civil Engineers, gives some significant figures regarding the cost of repairs on the two types of docks, in which it is shown that the least average annual expenditure for repairs and maintenance was $230 per year for the stone dock at Mare Island, while the highest expenditure was that upon the Brooklyn navy yard wooden dock, above mentioned, which averaged $85,500 per year. A comparison of three stone docks, those at Boston, Norfolk, and Mare Island, shows an average yearly expenditure of $1558, while the average on four timber docks at New York, League Island, Norfolk, and Port Royal, was $13,364. Commodore Endicott, Chief of the Bureau of Yards and Docks, stated that a timber dock has to be practically rebuilt in from twenty to twenty-five years, the experience of the navy all tending to prove that the masonry dock is superior in practically every respect.— Scientific American.

COAST TELEGRAPHIC COMMUNICATION.

By Charles Bright, F. R. S. E., A. M. Inst. C. E.

(History.)

Although electrical communication with lighthouses and light vessels has been a subject of discussion for a number of years, but little has been actually done in that direction. We have, in fact, scarcely emerged from the experimental stage in this class of work.

Let us pass in review the state of affairs as regards operations of this character so far carried out. In 1870 an essay was made to establish a floating telegraph station off the Land’s End. The Telegraph Construction Company was the promoter of this enterprise, besides carrying it through in every particular. In the first instance Capt. Burrows was the principal moving spirit in the scheme.

The Brisk, an old corvette, was fitted up with a telegraph cable, towed out to a position some fifty miles from the shore, and anchored in sixty fathoms of water, using a four-ton Martin’s anchor, and 400 fathoms of chain. The telegraph cable, we are told, was taken to the masthead, and when the vessel rolled the cable beat so heavily against the ship’s side that it was injured considerably. When the ship swung to the tide the cable had to be lifted over the vessel, the consequence was that it frequently fouled the chain and was broken.

This experiment was maintained from April 14th to June 16th, 1870. No dependence could be placed in the communication, as the cable was never in a satisfactory condition for more than a few days together. Some iiS,000 was expended over this experiment. The experience gained led to the introduction and adoption of Bedwell’s hollow-swivel device— patent No. 367 of 1876—in subsequent trials. By this plan the telegraph cable is drawn through the center of a mooring swivel having a hollow spindle. From this revolving swivel one or more chains lead to the moorings in a downward direction; in an upward direction a chain, or chains, lead to the inside of the vessel in the ordinary manner. The end of the electric cable below the vessel is passed up through the hollow swivel, over a sheave to inboard the vessel in such a way as ensures it always being a certain distance from the mooring chain. It so avoids chafing with it. To prevent the cable from being injured by the swinging of the vessel with the tide, which occurs four times each day, a sufficient quantity of cable is wound on a revolving drum placed in a revolving frame. The whole, or any part of the, apparatus may be kept in a tank containing water. The chain which is wound on the drum may be paid out in the event of it being necessary to veer the ship’s chain cable.

From 1870 to 1884 nothing further was attempted in the direction of lightship telegraphic communication. In the early part of the latter year a telegraph cable was established by the Telegraph Construction Company between the Sunk lightship and Walton-on-the-Naze. The vessel was of 189 tons; builders’ measurements, 90 ft. long by 21 ft. 6 in. broad, and 10 ft. deep. This ship proved to be too small for the purpose; she shipped much water in heavy weather, and was severely strained at the bows through the extra weight of a heavy swivel and the tension of taut chain bridles. Moreover, in heavy gales, spray would at times entirely eclipse the light, owing to the ship being pinned down by her moorings and pitching heavily. The moorings consisted of two lengths of ij^-in. chain lying east and west, forming two arms, with a Bedwell swivel at the junction. The anchors were of two and three tons respectively, of the mushroom type. The depth at high water was ten fathoms.

It was originally intended to thread the telegraph cable through a double-chain cable of special construction as designed by Mr. F. R. Lucas—patent No. 3463, of 1881. One of the main features in this patent was the ingenious swivel or revolving joint for the cable there suggested. This revolving joint was of such construction as always to permit of the cable revolving freely in either direction, and so allowing its turns to run out, besides providing for the movement of such parts—within certain limits—in any direction, at all times preserving the electrical continuity and insulation of the conductor. Thus, by means of this novel arrangement, the telegraph cable could be relieved of the turns or twists occasioned by the ship swinging to the tide, without in any way interfering with its electrical duties. It was found, however, that this cable presented great difficulties in manufacture.

Moreover, it was thought that the incessant hammering involved would tend to affect injuriously the electric cable within; and it is certainly quite possible that the vibration here entailed might be the cause of disintegration in the conductor, or dielectric, at the joints. Subsequently a steel wire mooring cable was adopted, with the ordinary electric cable—of light type—inside. This did not prove a success, three or four breaks occurring between December, 1884, and March, 1885. In March, 1885, the steel mooring cable was replaced by ordinary chain, and a light type telegraph cable used for connecting up on board and veering with. This cable was passed through the hollow spindle of the swivel already described, and 200 fathoms of it kept wound on a revolving drum. In this connection it may be mentioned that the late Captain Robert Halpin, R. N. R., has pointed out that it is only, within 50 or 60 fathoms of a lightship that any damage occurs to the telegraph cable.

It would be altogether exceeding our scope to go further into the details of this early experiment of telegraphic communication with the Sunk lightship. Suffice it to say that the contractors and every one concerned did their utmost to make it a success. The result, however, could hardly be looked upon with favor, there being as many as ninety days of interruption during two years. The experiment was begun in December, 1884, and after maintaining it at heavy cost for a year, was handed over by the contractors to the Trinity Board in March, 1886. The pioneer work done by the Telegraph Construction and Maintenance Company in this matter must never be forgotten. It has, moreover, been most useful in a general way as the only data to work upon in similar undertakings.

The communication between the Sunk and the shore was both telegraphic and telephonic, the telephone being preferred; indeed, this popular instrument proved by far the most useful, and could be used when both the “Morse” and Wheatstone’s A. B. C. were unworkable. Next in usefulness to the telephone was the A. B. C., the “Morse” recorder being practically never used in ordinary work. The length of the cable was nine nautical miles, and the distance over ground was 8.8 nautical miles.

There were four extra men employed on board the Sunk, but it does not follow from this that any extra hands would be required as a rule, for it was only necessary in this experiment on account of the antiquated form of windlass, and the frequent kinking of the cable, involving periodic repairs. All the men employed were regular lightship hands. Those singled out for telegraphic duties and cable repairs showed great aptitude in acquiring the details of the work, as regards jointing, splicing, and using the instruments. Though going a long way to meeting the difficulties to be contended with, the plan of passing the telegraph cable up over the bows of the lightship through a hollow revolving swivel was not found to be as perfect as was expected previous to the Sunk experiment. Means may yet be discovered by which the difficulties then experienced will be overcome. Meanwhile it may be remarked that the very reason why telegraphic communication with a lightship is required at all is due to the somewhat frequent occurrence of wrecks in the immediate vicinity, the lightship itself being very often placed on a reef of some sort. If, moreover, a strong current prevails, as is not uncommonly the case, the cable is liable to get shifted, and twisted up with the lightship moorings.

It has been suggested by Mr. H. Benest, A. M. Inst. C. E., that the cable might suitably stop short of the lightship, by its end being taken up to a buoy within such a distance of the vessel as would be outside her range of swing. According to this plan the buoy would be constructed with a central hawse for the telegraph cable to pass through. There would also be other hawse pipes for its moorings, which should be carefully carried out in different directions, and at some distance from the electric cable. The conductor of the cable would, in this device, be led into a water-tight box on the upper part of the framework of the buoy, to make connection with a lighter type of veering cable, which should extend from the lightship to the buoy. On board the lightship some length of the veering cable could be kept on a drum, which drum could be mounted on a traveller, free to run right round the ship on the bulwark rail. The signalling instrument would require to be disconnected when necessary to run the drum from one side of the ship to the other when swinging. In order to keep the cable in its normal state as regards lay, the drum should be pivoted. Respecting the class of buoy for this purpose, the Trinity House have of late years adopted one which might prove suitable. It is of peculiar shape, having a cylindrical belt round its circumference near to the base, which has the effect of producing great steadiness. Within recent times, experiments have been made with some success in the direction of communicating telegraphically through ordinary iron chain. By this plan ordinary electric cable might terminate at the mooring of a light vessel and her own chain be left to complete the circuit. The chain cable being practically a bare conductor, the external presence of rust—or paint—would be a distinct advantage, inasmuch as it would play the part of an insulator. An ingenious form of electrical swivel has been devised by Mr. James Wimshurst, F. R. S., for avoiding the kinks in cables attached to moored lightships swinging with the tide. It was exhibited at the annual conversazione of the Royal Society in 1894, and might be useful in this connection. Mr. Wims-hurst’s device does not, however, in any way meet one serious source of trouble—that of constant wear and tear on the bottom, due to rise and fall.

For further and full particulars regarding the work already done—and which it is proposed should be done—in this direction, the reader is referred to the Blue-book of the Royal Commission on Lighthouses and Light Vessels. This Commission commenced sitting in 1892, and has only lately completed its periodic deliberations. In the result, it has issued five reports, respectively in 1893, 1894, 1895, 1896 and 1897. The Commission paid a visit to Denmark in 1896 to inspect the very complete telegraphic arrangements with light vessels and lighthouses on that coast, subsequent to which they drew their final report on this all-important question. The reader’s attention may also be called to a paper on “Coast Telegraph Communication,” read before the Balloon Society in 1892, by Mr. Benest.—The Engineer.

THE PROPOSED ADDITIONS TO THE ACTIVE LIST.

The proposal of the Minister of Marine to increase the list of officers of the navy by 1 vice-admiral, 5 capitaines de vaisseau, 25 capi-taines de fregate, 75 lieutenants, and 80 engineers, has been approved by the Commission de la Marine of the Chamber, except as regards the vice-admiral, which is not thought necessary, as by the present list when all appointments are filled there will still be 2 vice-admirals for disposal. This increase to the number of officers being contemporaneous with a similar increase in the English navy has given occasion for a comparison of the prospects of advancement in the two Services, which the Temps gives as follows:—In the English navy the percentage of admirals to all junior grades up to and including that of lieutenant is 3.7 per cent., and to the superior grades of captain and commander 13 per cent. The percentage of superior grades (namely, captain and commander) to the lieutenants being 39 per cent. In the French navy, by the new increase, the above proportions are respectively 3.83 per cent., 12.3 per cent., and 44.63 per cent., from which it appears that though the chances of superior officers obtaining flag rank are slightly less favorable in the French than in the English navy, on the other hand the French naval lieutenant has a better chance of rising to the rank of captain or commander than his English confrère.—Journal Royal United Service.

SHIPS OF WAR.

[England.]

H. M. S. Pomone.

When recording the trials of her Majesty’s third-class cruiser Pactolus in our issue of October 28th, 1898, we incidentally mentioned that a sister ship, then building, would be engined by the same firm, Messrs. John Penn and Sons, of Greenwich. This vessel, the Pomone—a full page illustration of which we gave in a previous issue, November 26th, 1897— has now been so far completed as to have been able to undergo her speed and other trials, which have taken place during the past fortnight.

As the Pomone is in every respect a duplicate of the Pactolus, both as to dimensions, displacement, type of engines, boilers, etc., we do not repeat the particulars, as they will be found fully given in the issue of October above mentioned. Some valuable experience having been acquired during the trials of the Pactolus, especially in connection with her boilers—they being of a comparatively new type, the Blechynden water-tube—great care has been given to the boiler installation of the Pomone, so as to ensure satisfactory results, free from delay, when under trial.

The contract requirements of the vessel’s trials were exactly the same as those of the Pactolus, viz. the development of 3500, 5000, and 7000 indicated horse-power by her engines, in the coal consumption, natural and forced draught trials respectively; and from the results attained at them, which we give below, it will be seen that these requirements were in each case largely exceeded.

Having been built in Sheerness Dockyard, and of only a moderate water draught, her trials took place in the North Sea. A previous preliminary run having been made to see that all was in order, on February 16th the vessel left Sheerness and proceeded to sea for a thirty-hours’ coal consumption trial at 3500 horse-power, her water draught at the time being 12 ft. forward and 15 ft. aft; the weather being fairly good. This trial was continued without intermission or stoppage until completed; the mean results attained at it being that a steam pressure of 242 lbs. per square inch was easily maintained in the boilers with an air pressure in the stokeholds of .88 in. of water; the engines making 173.7 and 172.6 revolutions a minute for starboard and port, and developing respectively 1798 and 1811 indicated horse-power, or a total of 3609; the vacuum being a mean of 25 in., and the speed of ship 16½ knots an hour, coal having been consumed at the rate of 2.45 lbs. per indicated horse-power per hour. This trial, during which the engines and boilers worked in a highly satisfactory manner and gave no trouble, was completed on Friday, February 17th, when the ship returned to Sheerness.

On Tuesday, February 21st, the weather being rough, the ship proceeded on a natural-draught trial of eight hours’ duration, on which she attained the following satisfactory mean results: With the vessel drawing the same water as before, and steam maintained at 220 lbs. pressure per square inch in the boilers, with an air pressure of 1.4 in. of water in the stokeholds, and the starboard and port engines making 198.3 and 203.6 revolutions per minute respectively, there was developed by them a gross total of 5617 indicated horse-power, giving the ship a speed of 20 knots an hour.

Having cleaned boiler tubes, and seen that all engine and boiler connections, etc., were in order, the Pomone proceeded to sea on Saturday last for a four-hours’ full-power—7000 indicated horse-power—forced-draught trial, the weather being very fine, and the sea fairly smooth. The results of this trial, which were highly satisfactory, were: With the ship having a slightly deeper water draught than on the previous trials, and a steam pressure in her boilers of practically 252 lbs. per square inch, maintained with an air pressure of 2.777 in. of water, the revolutions of the starboard and port engines were 219.6 and 221 per minute respectively, and the gross total power developed by them 7340 indicated horses, giving the ship a speed of 21.5 knots an hour.

From the foregoing recorded results of the Pomone’s trials, it will be seen that the contract power requirements were exceeded at each, and that the engineers have beaten their own power record made in the case of the Pactolus, which was the highest then attained in the class of vessel. The trials of the Pomone have also been noteworthy, in that they have been continuous and without a break, and taking the time actually occupied in accomplishing them, have been completed within a week. The officials present at them were: Mr. F. H. Lister, representing the Ad miralty; Mr. R. H. Andrews, chief engineer of Sheerness Dockyard; Mr. E. Thomas, of the Sheerness Fleet Reserve; and Mr. W. B. Dixon, representing the contracting engineers, Messrs. Jno. Penn and Sons. The vessel was in charge of Commander G. C. A. Marescaux, of the Sheerness Fleet Reserve.—The Engineer.

H. M. S. Ariadne.

H. M. S. Ariadne, a first-class protective deck cruiser, of the improved Diadem class, built and engined by the Clydebank Engineering and Shipbuilding Company, Limited, on the Clyde, completed on Tuesday, the 7th inst., a series of contract steam trials, and the detailed results are given on the next page. The Ariadne, so far as the hull is concerned, in which we include offensive and defensive qualities, resembles closely the Diadem class, which has been fully described in Engineering, the preceding vessel of the class built at Clydebank, being the Europa. The only difference is in the boilers. The boilers of the later ships have been designed with slightly more heating surface than the Europa, 47,300 square feet of heating surface and 1390 square feet of grate area, the ratio being 34.0 to 1; while in the case of the Europa, with the same number of boilers, the ratio is 27.73 to 1, the heating surface being 40,600 square feet, and the grate area 1450 square feet. The Ariadne, of course, represents the later practice, and as the horse-power to be developed is 1500 more than with the Europa, it will be seen that the coal burned per square foot of grate per hour is higher. On the full-power trial it was nearly 22 lbs. per square foot of grate, as against 21 lbs. in the Diadem class. The power per square foot of grate was 13.2 indicated horse-power, as against 11.63 indicated horse-power in the Europa; but in special trials both these results have been exceeded. The heating surface is equal to 2.48 square feet per unit of power maintained; in the Europa it was 2.38. If the table now given be compared with.the corresponding one published by us in July last, giving the Europa’s results, it will also be seen that the coal consumption is much less. In each type of ship there are 30 Belleville boilers with economizers. The engines are of the triple-expansion type, but the arrangement in the Ariadne differs from that in the Europa. Instead of the four cylinders being placed as follows from the bow end: High-pressure, intermediate pressure, and the two low-pressures with the valves between each, the order is as follows: Low-pressure slide valve, low-pressure cylinder, high-pressure cylinder, high-pressure piston valve; intermediate pressure piston valve, intermediate pressure cylinder, low-pressure cylinder, and low-pressure piston valve. Thus the cylinders are in pairs as closely together as is possible, and the sequence of cranks is—high-pressure, intermediate pressure, forward low-pressure, after low-pressure, the first and third named being at right angles, as are the other two. This arrangement gave practically no vibration. The diameters of cylinders are 34 in., 55½ in., 64 in., and 64 in. by 48 in. stroke. They were designed to give the full power at 120 revolutions, while in the case of the Europa the designed speed was no revolutions, although with 112.4 revolutions 17,010 indicated horse-power was got, while the Ariadne got 19,156 indicated horse-power with 118.9 revolutions.

RESULTS OF STEAM TRIALS OF H.M.8. ARIADNE (11,000 TONS AND 18,000 INDICATED HORSE-POWER).

BUILT AND ENGINED BV THE CLYDEBANK ENGINEERING AND SHIPBUILDING COMPANY, LIMITED.

The Ariadne, it may be said, is 435 ft. long between perpendiculars, 69 ft. beam, and at 24 ft. 7 in. draught displaces 11,070 tons. As will be seen from the table, the vessel had water ballast in her to insure that the draught would be even greater than that stipulated for, and yet on all occasions she succeeded easily in attaining her speed over the measured distance course between the Dodman and Rame Head, the top mean speed for 19,156 indicated horse-power being 21.5 knots, against the 20.75 knots for 18,000 indicated horse-power anticipated in the design. The vessel left Chatham Dockyard on Monday, the 30th ult., and after proceeding to Sheerness for adjustment of compasses and having a preliminary run, she commenced her 30-hours’ trial of one-fifth the total power on Tuesday afternoon, the 31st, and anchored in Plymouth Sound on the following night about 10 o’clock. The results of this trial proved to be satisfactory, the mean indicated horse-power being 3758, with 70.3 revolutions; while the draught of the ship was 25 ft. 5 in. forward and 26 ft. 2 in. aft, the speed being 13.3 knots. The following day at noon she went to sea for her deep-water anchor and cable trials, at the conclusion of which the 30-hours’ trial at 13,500 indicated horsepower was proceeded with. During the night she steamed up the English Channel, and soon after daylight was on the deep-water Admiralty measured run between the Dodman and Rame Head. This distance of 23 miles was run over four times, the mean speed averaging 19.7 knots. She then steamed out to sea and returned to anchor in Plymouth Sound on Saturday morning, the 4th inst., having completed a most satisfactory trial, the mean results being 14,046 indicated horse-power, with 109.1 revolutions, a coal consumption of 1.73 lb. per indicated horse-power, and a mean speed for the 30 hours of 20.1 knots. On Monday of this week the vessel proceeded on her eight hours’ full-speed trial, when, as stated, the mean power was 19,156 indicated horse-power for 118.9 revolutions, against the 18,000 indicated horse-power for 120 revolutions required by the contract, and the coal consumption was 1.66 indicated horse-power per hour, a very good result. She afterwards steamed back to the Nore, whence, after carrying out the gunnery and circle-turning trials, she will be taken up to Chatham yard for completion for commission.—Engineering.

New Ships.

The supplemental programme of naval construction sanctioned by the House of Commons at Mr. Goschen’s request on 22nd July last comprised four battle-ships, four cruisers, and twelve torpedo-boat destroyers. The contracts for the four battle-ships and two of the cruisers have now been given out. The Thames Ironworks and Shipbuilding Company has secured the contract for the construction of two of the battle-ships and their machinery, and the other two battle-ships with their machinery will be built by Messrs. Laird, of Birkenhead, and the Palmer Shipbuilding Company, at Jarrow. The contracts for the two first-class cruisers, which are to be of the large armored type, foreshadowed by Mr. Goschen in his speech in the House last June, have been allotted to the following firms:   One      to the Fairfield Company and the other to Vickers, Sons, and

Maxim, at Barrow-in-Furness; while two others of a similar type are, it is reported, to be built at Devonport and Pembroke Dockyards respectively; the engines for the latter being supplied by Messrs. Humphreys, Tennant, and Co., of Deptford, London. Contracts for the remaining two cruisers, which will be of a somewhat smaller type, will be placed shortly.

The new battle-ships will differ somewhat from the Formidable class, but the differences will be mainly differences of detail. They will possess rather more speed than the Formidable class, and will draw somewhat less water. As Mr. Goschen significantly observed: “They will be more calculated to pass through the Suez Canal without lightening.” Another point of difference is that the new battle-ships will carry slightly less armor. At present names have not been found for the new vessels. The fact that two of the new vessels are to be built by the Thames Ironworks Company is due entirely to tenders submitted, and with the exception of the Albion, launched last year, will be the first important orders executed by that firm for the Government for some years. In the present instance a circumstance greatly in favor of the builders is that they have two vacant slips side by side, one recently occupied by the Albion, and the other by the Japanese warship Shikishima. The two vessels to be constructed will be absolutely in duplicate, and can therefore be completed more expeditiously and at less cost than if they were of a different class. All four battle-ships are to be delivered in two years and three months from the date of the order, and if possible they are to be completed at an earlier date.

The two new cruisers will be of an improved Cressy type, and will be the largest and most powerful vessels of their class as yet designed for any navy. Their length between perpendiculars will be 500 feet; beam, extreme, 71 feet; mean draught, 26 feet; displacement, about 14,100 tons; speed, 23 knots; H. P., 30,000; armament, two 9.2-inch guns with armored shields, sixteen 6-inch Q. F. guns in casemates, fourteen 12-pounder Q. F. guns, three 3-pounders, and two submerged torpedo-tubes. The protection to the 9.2-inch and 6-inch Q. F. guns will be equal to that provided in the Powerful and Terrible. The guns will be of the more modern type adopted for the Cressy class, and of considerably greater power than those of any other cruiser. The 9.2-inch guns will be mounted in barbettes, protected by 6-inch nickel-steel armor, with 6-inch hoods; there will be four more 6-inch guns than in the Cressy, and they will be mounted four on each side on the main deck in 6-inch casemates, and four immediately above them on the upper deck, similarly protected. The sides will be protected by 6-inch steel armor, extending forward to the ram, where it will be of somewhat lessened thickness, while at the after-end of the belt there will be an armored athwartship bulkhead of 5 inches. There will be two armored decks, the upper one horizontal, of i-inch steel, and the lower turtle-backed, of 4-inch steel, tapering to 2 inches. The steel hulls will be unsheathed. The measured-mile speed on an eight hours’ trial with natural draught will be 23 knots. The continuous sea-speed with smooth water will be 21 knots. Water-tube boilers will be adopted and twin screws. The capacity of the coal bunkers will be 2500 tons, thus giving them a greater radius of action than the new cruisers of foreign navies. Both ships are to be completed in two years and six months at the outside.

It will thus be seen that the new ships will be unexcelled both as regards protection and speed. It is true that both France and Russia are building a certain number of so-called 23-knot cruisers, but this speed is only to be maintained for 12 hours, and that through forced draught, while in our ships the 23 knots will be obtained under natural draught, and judging from the good results obtained from the Terrible, there will in all probability be no difficulty in getting and maintaining this speed. On the other hand, the sea-speed (under natural draught) of both the French and Russian ships is only to be 19 knots as against the 21 knots of our ships, and in this connection it may be as well to recall that quite lately the Diadem ran home from Gibraltar with a foul bottom at a mean speed of 19.7 knots.—Journal Royal United Service.

[France.]

The French Submarine Boats.

The mystery surrounding the submarine torpedo-boats being constructed in France is obviously calculated to provoke a good deal of curiosity as to the special features of this new type of vessel. Selected among the various projects which were some time ago submitted in competition, the boats are expected by French engineers to prove remarkably destructive, and to effect “an entire revolution” in naval strategy. These claims have been so frequently made by designers of new types of fighting machines in France, that one is inclined to be sceptical as to whether the submarine boat is capable of doing any practical work. Nevertheless, it cannot be overlooked that the performances of the Gustave Zédé in the harbor of Toulon have given a good deal of satisfaction to naval experts on the other side of the Channel, who declare that there are great possibilities in the way of submarine fighting. During the past few days M. Lockroy has visited Toulon in order to witness the manoeuvres of the Gustave Zédé, which successfully repeated its performances of a week or two previously. Appearing about 500 metres from the Magenta to take aim, the boat sank before the guns could be trained on it and appeared 300 metres nearer, when, according to one account, it accomplished the extraordinary exploit of sending a torpedo “in an absolutely straight line between the funnels of the battle-ship.” The French journalist remarks that had the torpedo been loaded the Magenta would have gone to the bottom. Having theoretically sunk the battle-ship, the Gustave Zédé disappeared and came to the surface again 100 metres behind the vessel. It appears that the manoeuvring was so rapid that the gunners were utterly nonplussed, not only by the instantaneous and erratic appearance, but also by the small target offered when at any distance. There was a general impression that it was extremely difficult, if not impossible, to sink the torpedo-boat. Nothing, of course, is known as to the details of construction, since these are being kept a profound secret. It is, however, possible to exaggerate the importance of the much talked-of “eye,” as we presume that this is merely an improved form of lookout with, perhaps, electric reflectors, throwing a strong light ahead. In any event, it obviously cannot be used for getting the bearings under water, as the tactics of the boat are invariably the same; that is to say, it rises about 500 metres from the vessel to be attacked, and, after taking aim, sinks; and, continuing in a straight line, reappears 300 metres further on, when it discharges the torpedo. It is obvious, too, that the difficulties of hitting a battle-ship would be considerably increased if it were steaming instead of remaining still, as was the case with the Magenta. The boat trains its torpedo at a distance of about 500 metres, and travels under water 300 metres before discharging. Supposing the submarine boat makes eight knots after aiming, by the time it rose to the surface

the battle-ship would be half a mile away. In the event of the boat appearing-ahead, so that the battle-ship would not have time to put about, it would still have to calculate the probable movements of the vessel, and during the time it took to train on there would be every prospect of the boat being sunk. The hitting of a battle-ship under full steam would be merely a matter of chance. Again, the Gustave Zédé being propelled by electricity stored in secondary batteries, can only have a very small range of action, and could, indeed, scarcely leave the ports. This is why French engineers are giving special attention just now to the Narval, which, it is expected, will be completed in the course of two or three months. It is being built upon competitive designs sent in by M. Laubeuf a marine engineer. This vessel will be propelled at the surface by steam, and under water by electricity. The small engine not only works the propeller but operates a dynamo which charges secondary batteries. When the boat is to go under water the funnel is unshipped and the boat is propelled by electrical power. It is said that the Narval will carry enough fuel to steam 252 miles in twenty-four hours at 12 knots, or 624 miles in seventy-eight hours at eight knots. Under water it will do 25 miles at eight knots. Though it may be doubted whether these boats will be anything like so practical and efficient as French marine engineers claim for them, it would yet be unwise to depreciate them unduly, and they are certainly interesting as showing the direction in which trans-Channel engineers are endeavoring to strengthen the marine. As France finds it hopeless to keep pace with England in naval construction, she is obviously bent upon changing her tactics, which are something like those of the sword-fish attacking the whale. The results obtained in this country and in Turkey several years ago with Nordenfeldt boats were quite as good as those obtained in France, but the whole scheme collapsed.—The Engineer.

[Japan.]

Asama.

The twin-screw cruiser Asama, recently built by Messrs. Armstrong, Whitworth and Co. to the order of the Japanese Government, from the designs of Mr. Philip Watts, the head of the Elswick shipyard. She is 408 ft. long and 67 ft. wide. With her powerful armament, strong defensive armor, and high speed, the vessel forms a most important addition to that formidable navy which is growing up so quickly in the Far East; a navy which is not only strong in its number of vessels, but also in the high efficiency of the separate ships, the professional attainments of the officers, and the seamanlike character of the crews.

This cruiser has no less than 2100 tons of armor worked into her construction. She has a belt of Harveyed steel which extends 2 ft. above and 5 ft. below the normal water-line, and tapers from 7 in. in the thickest part to 3½ in. at the ends. Above this the sides are protected by 5-in. armor which extends over the whole of the midship part and joins the armored bulkheads that connect with the main gun positions. The latter are protected vertically by 8-in. Harveyed steel plates, with an additional inner skin 1 in. thick, there being a 1-in. roof. There are ten casemates of 6-in. Harveyed steel. To protect the bow torpedo discharge there is on each side 6-in. plating, which extends from the stem 25 ft. aft. The armored deck is 2 in. thick and is curved in an athwartship direction to join the lower edges of the belt. There is a 2-in. steel plate worked forward to support the lower part of the ram bow, the armored deck extending forward to strengthen the upper part in the usual way. There is an armored conning-tower forward and an armored observation-tower aft. The armament consists of four 8-in. quick-firing guns mounted in pairs in the armored positions referred to forward and aft, as shown in our illustration. The forward guns are 25 ft. above the water-level, and the after pair 1 ft. lower. There are fourteen 6-in. quick-firing guns, ten of which are placed in the 6-in. steel casements before referred to. On each side of the ship two are placed at each end of the armored citadel, one above the other, as is shown in the engraving. This accounts for eight of the 6-in. guns, the remaining two of the ten in casemates being placed on either side of the ship on the main deck. The other four of the fourteen 6-in. guns are on the upper deck and are protected by shields. The lighter armament consists of twelve 12-pounders and various other weapons of lighter nature. There are five torpedo-tubes for 18-in. torpedoes. One of these is through the stem, and is protected as stated, whilst the other four are under water discharges.

The machinery for the Asama has been supplied by Messrs. Humphreys, Tennant and Co., and is generally of the usual type, there being two sets of inverted direct-acting engines and cylindrical boilers, pressed to 150 lbs. to the square inch. The legend power is 13,000 indicated horsepower with natural draught and 18,000 with forced draught, whilst the corresponding speeds are 20 knots and 21knots. The normal coal capacity is 700 tons, and with this weight on board the draught is 24 ft. 8 in.; but there is storage for 1450 tons if all bunkers are filled.

The Asama has more than exceeded the contract conditions, running for six hours with open stokeholds when the horse-power was somewhat above the 13,000 and the revolutions 140 to 142 per minute, at which the speed registered was 20.37 knots. On the forced-draught trials 19,000 indicated horse-power was reached, the revolutions averaging 158 per minute and the speed being 22.07 knots. The gunnery trials and anchor trials have also been successfully carried out.—Engineering.

[United States.]

Albany.

The protected cruiser Albany, which has been built for the United States Government by Sir W. G. Armstrong, Whitworth and Co., Limited, at Elswick, Newcastle-on-Tyne, was launched on Saturday afternoon the 14th inst. The Albany is a sister ship of the Amazonas, which the Elswick firm built for the Brazilian Government, and which was launched in December, 1896. Last year the Amazonas, on her completion, was transferred to the United States flag, and, under the name of the New Orleans, took part in the war with Spain. The Albany is of the following dimensions: Length on the water-line, 330 ft.; length over all, 358 ft.; extreme beam, 43 ft. 9 in.; mean draught on a trial displacement of 3500 tons, 16 ft. 10 in. She has a protected steel deck extending from stem to stern, and is fitted with 14 water-tight bulkheads extending up to the berth deck. In addition to these divisions, she is fitted with a double bottom, minutely subdivided into watertight compartments; and the store rooms and coal bunkers below the protected deck are also watertight. The armament of the Albany is as follows: Six 6-in., four 4.7-in. guns, ten 6-pounders, and four 1-pounders. There are two machine guns for use in the boats and in landing and in the military tops. The vessel is fitted with two military masts, with two tops in each mast. The propelling machinery, which is being built by Messrs Hawthorn, Leslie and Co., Limited, at their St. Peter’s Works, consists of two sets of triple-expansion engines, driving twin-screws, the maximum indicated horse-power being 7500, at 160 revolutions per minute, the guaranteed speed being 20 knots. There are four double-ended Scotch boilers. The vessel will be lighted by electricity, the plant consisting of three dynamos and engines.—Engineering.

Battle-ships and Monitors now Building for the Navy.

There are now completed and in commission in the United States Navy five battle-ships, four of which are of the first and one of the second class. These are the Oregon, Indiana and Massachusetts, of 10,288 tons, and the Iowa, of 11,410 tons, first-class battle-ships, and the second-class Texas, of 6315 tons.

There are now building in our yards eight first-class battle-ships of over 11,000 tons, whose aggregate displacement is 94,125 tons. As the aggregate displacement of the battle-ships now in commission is about 60,000 tons, it will be seen that we have over 50 per cent, more tonnage of battle-ships in course of construction than took part in the operations of the late war.

These eight vessels represent three successive naval appropriations. The Kentucky and Kearsarge were authorized in 1895 and are about ready to undergo their steam trials; the Alabama, Wisconsin and Illinois were authorized in 1896 and are about 60 per cent, completed; while the Maine, Ohio and Missouri were authorized last year and are in the early stages of their construction.

Judging from the rate of progress achieved in the past, we may expect to see the first-named ships in commission by the close of the present year; the three Alabamas by the close of 1900, and the Maine with her mates in the winter of 1902-03.

In addition to these fine vessels, we unfortunately have under way four ships of an obsolete and discredited type, which will be known as the Arkansas, Connecticut, Florida and Wyoming. They are monitors, pure and simple, and represent a class of ship which was built in the early experimental stages of warship construction, when designers were feeling their way toward the ideal fighting ship as represented by the eight battleships above mentioned. These four monitors were ordered by Congress in the face of the opinion and advice of the men who design and the men who fight the vessels of our Navy. The fact that we are committed to the construction of four of these archaic curiosities serves to show to what absurdities Congress can be committed when it sets up its own judgment against that professional opinion which should guide it in such purely technical questions as those of warship design.

Including the monitors, we now have under construction the twelve armored vessels which our artist has shown grouped together in the accompanying illustration. As each of the ships is drawn with careful attention to detail, particularly in the matter of armament, the group conveys an impressive idea of the exceptional offensive qualities of the forthcoming addition to our Navy.