introduction of the rifled cannon, and its subsequent development,

have increased very much the weight of this part of the equipment of a vessel-of-war, and the necessity of accommodating the stowage of charges of powder much increased in size, and of ammunition for the secondary batteries, which must be most liberally supplied, makes an absolute demand on an increased portion of space. Again, the increased speed now considered indispensable makes a similar demand for space, and carries with it as well an increased proportion of the total displacement. In a wooden hull it would be impossible to reconcile these demands, in consequence of the weight of the hull itself. The hull and hull fittings of an unarmored cruiser built of wood will weigh from 49 per cent. to 52 per cent. of the total displacement. With high-powered engines it is doubtful if sufficient strength can be obtained with even 52 per cent. of the displacement for the hull, and this must suppose the absence of all protection to buoyancy, as water-tight compartments. The hull and fittings of a steel cruiser, exclusive of protective decks, will weigh from 39 per cent. to 44 per cent. of the total displacement. Suppose a 4500-ton ship built of wood weighing 50 per cent. of the total displacement, and the same ship built of steel weighing 40 per cent. of the total displacement, the respective weights of the hulls will be 2250 tons and 1800 tons, a difference of 450 tons, the steel hull being one-fifth, or 20 per cent., lighter than the wooden one. This will allow for increased weight of ordnance, protective deck, or increased coal endurance, as may be decided when considering the service on which the ship is to be employed. But notwithstanding the saving thus obtained, the question of weights is still full of difficulties and embarrassments, and it is found impossible in the same structure to accommodate all demands from the different departments concerned in the equipment of a vessel-of-war. The sail-power has been reduced, so as to save weight of spars and sails, which have become of secondary importance, but this will not satisfy all the requirements of the problem. As articles appertaining to the old method of equipment are removed, those belonging to what are considered necessary under the new order of things are brought forward. Space is still to be found for movable torpedoes, for torpedo-boats, and for engines and appurtenances for electrical apparatus for lighting the ship, for search-light, and other ordnance purposes. It is evident that much study is needed to reduce weights in all the essential parts, so as to be able to accommodate all the devices which the progress of ideas continues to present. Much is yet to be done by the substitution of steel for iron in many parts of our engines, and experiments abroad lead to the hope that the weights of boilers may be much reduced, but as the question stands to-day it is impossible to provide any single ship with all the appliances that are considered necessary for a perfectly equipped vessel-of-war. Every ship, therefore, must present a compromise. Another reason for the transition from wood to steel hulls is the durability of steel as compared with wood. Referring to the large sums of money that have been appropriated under the head of construction and repairs, for which there is now so little to show (and disregarding the question of administration, which of course is vital, but which has no place in this chapter), the main reason for the deficiency in the results is that all this money has been expended in perishable material. Every ship that has been built of wood since the war has been a mistake. The most serious error was committed when the wooden double-turreted Monitors of the _Miantonomoh_ class were built, which, it is believed, was done against the protest of Captain Ericsson. The result was the early decay of these vessels, and the present defenceless condition of our sea-coast. The lifetime of a wooden ship is of short duration. It requires constant repairs, which amount in the long-run to rebuilding, and it is in this manner that so many of our old ships are still retained in service; but in the case of a wooden armored vessel these repairs are impossible without removing the armor. This was the condition of affairs with regard to these Monitors, and the consequence is that the country has to incur the expense of entirely new constructions. These are in durable material, and will give good account of themselves when called on. The steel hulls that it is now the intention shall compose the fleet, will, if well cared for, endure in perfect condition for thirty years. In fact, the lifetime of an iron or steel hull is not defined to any limit, and if a perfect anti-corrosive and anti-fouling composition can be produced, the limit may be regarded as indefinite. The foregoing remarks on our new navy apply to unarmored cruisers, a class of ships which supply a want in time of peace, but cannot fulfil the purposes of war. At such a time the armored ship is recognized as indispensable, and there is every reason why the construction of armored vessels should proceed simultaneously with that of the unarmored cruisers. These are a more intricate problem for study, need much more time to build, and are required, while at peace, as a school of instruction in which to prepare for war. Our selection of armor has been much assisted by the investigations of others, and we are in a favorable condition to make a decision on this point; and the type of vessel best suited for a cruiser seems to be settled, by the uniform practice of foreign nations, in favor of the barbette.[51] It must be remembered, however, that six months since we were not in a condition to proceed with the construction of armored vessels, depending on our own resources. We had to go abroad to purchase armor, or set ourselves to the task of establishing works where it could be manufactured. The establishment of these plants was the first thing needful, and until this was done it was impossible to make ourselves independent in this matter. The construction of our first unarmored cruisers introduced into the country the industry of rolling steel ship-plates; the construction of our new ordnance and armored ships has, in turn, introduced the new industries of casting and forging large masses of war material. This subject, so far as it relates to ordnance, was referred to a mixed board of army and navy officers, known as the Gun Foundery Board; this, with the aid and counsel of some of the ablest and leading steel manufacturers in the United States, submitted to Congress a report which presented a solution of the problem, and demonstrated on what terms the steel manufacturers of the country could be induced to work in accord with the government. The Board had under consideration only the subject of founderies and factories for gun construction, but the casting and forging facilities required for guns could be applicable to armor; thus in providing means for the manufacture of one, the other purpose was equally subserved. With material of domestic manufacture at hand, it will be the duty of the government to provide the navy with a fleet of ten armored cruisers of the most approved type. These vessels would form the outer line of defence of the coast during war, and should be of such force as to be able to contend with any second-class armored vessel of other nations. Some of them should be always in commission during times of peace, if only for instruction and practice purposes, and one should be assigned to each squadron abroad to carry the flag of the rear-admiral in command, to assert our position in the society of naval powers, able to give substantial “support to American policy in matters where foreign governments are concerned.” The ability to contend with armored vessels of the first class must be reserved for another type of ships, which are styled “coast-defence vessels,” and without which our new navy will not be thoroughly equipped for contributing its full share to defence at home. In considering armored vessels, what was said before as to the character of compromise that obtains in vessels-of-war must be borne in mind. All desirable features cannot be concentrated in any one ship; the special duty for which the vessel is to be used controls the selection. The sea-going armored cruiser is expected to keep the sea for a lengthened period: she must have large coal endurance. She may be called on to sustain more than one engagement: her supply of ammunition must be large. Her speed must equal that of the fastest sea-going vessels of similar type to enable her to pursue an equal or to avoid a superior force: hence much space and displacement must be assigned to engines and boilers. Thus the amount of her armor and the weight of her battery are affected by these other demands, which are the more imperative. In the case of coast-defence vessels the conditions are changed, enabling in them the full development of both offensive and defensive properties. These vessels are assigned to duty on the coast: they must be as fit to keep the sea as are the armored cruisers, and they must be able to fight their guns in all weathers that the armored cruiser can fight; but as they do not require the coal endurance nor the speed of the ship that is to keep the sea for lengthened periods, the weight saved in coal and machinery can be utilized in battery and armor. Such vessels constitute the main line of naval defence, as they can be made almost absolutely invulnerable and irresistible. Under an act of a late Congress a board on “fortifications and other defences” was occupied in considering the defences of the coast, and there were recommended by this Board two classes of “floating batteries” (so called), coast-defence vessels, and one class of low freeboard vessels for harbor defence. An examination of the designs of these vessels shows that they are replete with merit, and present some novel and valuable features. A justifiable limitation is put on the coal endurance and speed, though fair speed is secured; and altogether the plans prove there can be designed vessels of comparatively small dimensions, light draught, great handiness and manœuvring power, which can carry the heaviest guns, and be capable of contending on equal terms with the heaviest European battle-ships. The cut below represents the smaller of the type of coast-defence vessels. [Illustration: LIGHT DRAUGHT COAST-DEFENCE VESSEL, WITH DECK PLAN.] The largest class will be armed with two 107-ton guns in a turret, and two 26-ton guns in a barbette. The thickness of armor will vary from 16 to 18 inches. The second class will be armed with two 75-ton guns in a turret, and two 26-ton guns in a barbette. The thickness of armor will be from 11 to 16 inches. The smallest vessels, for harbor defence, modified Monitors, will be armed with two 44-ton guns in a turret, and two 26-ton guns in a barbette. The thickness of armor will be from 10 to 13 inches. A fleet composed of such vessels as are represented in the largest type would be able to engage an enemy at some distance from the coast—an important object in these days when the range of heavy rifled cannons makes it possible to shell towns from a great distance, and at points remote from shore batteries. Nominally we have now a fleet of vessels for coast defence, the old war Monitors of the _Passaic_ class; but the contrast between them and the vessels recommended by the Fortifications Board is about equal in degree with that between our wooden fleet and the new steel cruisers. It is intended that a movable automatic torpedo shall be utilized by all armored vessels, either by means of a torpedo-boat to be carried by armored cruisers, or by the vessel itself in the case of coast and harbor defence ships. The torpedo that has mainly succeeded thus far in recommending itself to the naval powers is that invented by Mr. Whitehead. Numerous efforts have been made by others in this field, but the difficulties that surround it are made very apparent by the paucity of the results. It will be understood that the torpedo, when launched, is left entirely to automatic control; hence, apart from the motive power, it is necessary that it shall possess directive power, vertically to control immersion and horizontally to control direction in the horizontal plane. In the Whitehead torpedo the immersion is well regulated, and if no deflecting influences are encountered, the direction is also preserved; but it fails where deflecting influences intervene. During the Turko-Russian war valuable experience was gained, and instances are known where the torpedo failed to operate from want of directive power. An instance is cited where a torpedo was deflected by striking the chain of a vessel at anchor, causing it to pass harmlessly to one side. Another instance is cited where the torpedo was deflected from the side of a ship owing to the angle at which it struck. It is evident that perfection cannot be associated with a weapon of this class that has not a strong directive force inherent in it. The torpedo invented by Captain J. A. Howell, of the United States navy, possesses this property to an eminent degree, and it is regarded by most competent experts as the successful rival of the Whitehead. In the Howell torpedo the power is stored in a fly-wheel revolving with great rapidity in a longitudinal vertical plane, and its gyroscopic tendency makes it impossible for the torpedo to deviate from its original course in a horizontal plane; the principle is the same as insures the accuracy of the rifle-bullet, enabling it to resist deflecting influences. The latest experiments of Captain Howell in controlling the immersion of his torpedo were very successful, and it is probable that the auto-mobile torpedo for our new navy will be an American invention. Liberality in experiments is indispensable in perfecting a device of this kind; it is to be hoped that such may be extended to the Howell torpedo.[52] [Illustration: THE HOWELL TORPEDO. _B_, fly-wheel. _C_, _C_, screw propellers. _D_, diving rudder. _E_, _E_, steering rudders. _F_, water-chamber containing automatic apparatus. _G_, firing pin. _H_, position of gun-cotton magazine.] The general reader is probably not aware of the effect on naval warfare produced by the introduction of the auto-mobile torpedo, affecting the constituents of the fleet itself. Formerly a fleet consisted of battle-ships alone, or with store-ships to provide consumable articles; to these were later added despatch-boats for the service indicated by their title; but since the introduction of the torpedo an additional fleet of torpedo-boats is considered necessary for the protection of the battle-ships. All armored ships are expected to carry at least one torpedo-boat, which is designed for operating against the enemy during an action at sea, and the universal adoption of this practice has led to the introduction into fleets of a new type of vessel called torpedo-boat catchers, whose primary duty it is to destroy the torpedo-boats of the enemy. For this purpose these vessels have phenomenal speed, and besides their equipment of auto-mobile torpedoes, are provided with powerful batteries of single-shot and revolving Hotchkiss guns, capable of penetrating all parts of a torpedo-boat. This type of vessel is now being tested by the English and the Continental governments, and forms one of the constituents of their fleets. The torpedo-boat is undoubtedly one of the features that should be introduced into our new navy, not only for their possible use on the high seas, but for the purpose of supplementing the harbor-defence vessels, while the type of vessel known as the torpedo-boat catcher would be a powerful auxiliary to the armored cruisers on the first line, or the more powerful vessels forming the second line of the coast defence. NOTES. For the new navy of the United States Congress has authorized the construction of twenty-five vessels, of which seven will be armored, sixteen unarmored, and two “such floating batteries, rams, or other naval structures for coast defence” as may be determined by the Navy Department. This list embraces five double-turreted Monitors, one armored battle-ship, one armored cruiser, eight partially protected cruisers, one dynamite-gun cruiser, four gun-boats, one despatch-vessel, and two torpedo-boats. Of the twenty vessels already built or ordered but three are in commission. They vary so much in type that the following conventional data may perhaps be of some use (see table on the following page), though it must be remembered that the performances stated are theoretical, except in the cases of the _Atlanta_, _Boston_, and _Dolphin_. The defects found in the _Atlanta_ when first tested were so easily remedied that the machinery finally developed a maximum horse-power which was only a little less than that required by the contract; while the _Boston_ reached a maximum of 4248.5 horse-power. In his last report to the President the Secretary of the Navy said: “The _Dolphin_ and the _Atlanta_ having both been completed, and having had trial trips, it is possible to compare them in their results with similar vessels built contemporaneously elsewhere. The _Dolphin_, of 1500 tons displacement, can be compared with the _Alacrity_ and _Surprise_, English despatch-vessels of 1400 tons each, and the _Milan_, a French despatch-vessel of 1550 tons, all built contemporaneously. The _Dolphin_ was designed for 2300 indicated horse-power, the _Alacrity_ and _Surprise_ each 3000, and the _Milan_ 3900. The highest mean horse-power developed upon trial was, in the case of the _Dolphin_, less than 2200; of the _Alacrity_, 3173; of the _Surprise_, 3079; of the _Milan_, 4132. The highest speed of the _Dolphin_, resulting from several trials, was 15.11 knots, running light; of the _Alacrity_, 17.95 knots; of the _Surprise_, 17.8 knots; of the _Milan_, 18.4 knots. “The _Atlanta_, the sister ship to the _Boston_, can be compared with the _Esmeralda_, the _Giovanni Bausan_, and the _Mersey_. All three were built in England: the _Esmeralda_ for Chili, the _Giovanni Bausan_ for Italy, and the _Mersey_ for the English government. The _Atlanta_ is of 3000 tons displacement; the _Esmeralda_, 2920; the _Giovanni Bausan_, 3086; and the _Mersey_, 3550. The _Atlanta_ was designed to attain an indicated horse-power of 3500, the _Esmeralda_ and the _Giovanni Bausan_ each 5500, and the _Mersey_ 6000. The trials had of the _Atlanta_ indicate that her engines will develop less than 3500 horse-power, while the _Esmeralda_ developed 6000, the _Giovanni Bausan_ 6680, and the _Mersey_ 6626. The maximum speed of the _Atlanta_ will be less than 15 knots, while that of the _Esmeralda_ was 18.28 knots, the _Giovanni Bausan_ 17.5 knots, the _Mersey_ 17.5 knots.”