IRON DEFENCES, ASHORE AND AFLOAT. ONE of the most conspicuous

subjects of discussion during the year which has just passed away has been that of iron defences on 4n4 and sea, and especially at sea. We have been told that the great , screw Navy we have just constructed will have to be reconstroste4, that the days of timber -ship* are over, that we mast feliamtiessi lead of the French, and have a fleet of iron-sided ships, on pain of being deprived of our naval supremacy, and of having our

line vessels made into lucifer matches by the shells of iron-clad

foes. Members of Parliament, captains of the Royal Navy, edi- tors, letter-writers of all kinds, the iron-shipping interest, have

been led away by strong assertions, and have hardly for a mo- ment ceased crying aloud for iron, iron, iron ! to save the State. The wildest delusions, the most unfounded statements, have been adopted by men who are sane enough on ordinary occasions. Extravagant plans for adapting iron to the sides of ships, and equally extravagant plans for protecting guns and guns' crews, have been cracked up in the newspapers, and in periodicals whose editors ought to know better. Imagination has been let loose, and- allowed to run riot on a question which is purely matter for scien- tific experiment, and which must be decided, if decided wisely, upon a broad ground of well-ascertained facts. -Without dogmatizing on the question at issue, we may say that at present the decision to be drawn from the facts already ascer- tained and made public, is against the advocates either of mailed ships, or ships built wholly of iron. Mailed ships would but very imperfectly answer the purposes for which sea-going vessels of war are designed, and iron ships would answer them still more imperfectly. Some future Hercules in science may discover what contemporary seekers have failed to find ; but at present the

chances are against him. It would be strange, indeed, were it to happen that armour, discarded gradually after the application of gunpowder to warfare, should be revived at a moment when the probability of improving artillery and projectiles is greater than ever.

Sir Howard Douglas, moved by the " slashing " article which appeared in the Quarterly _Review for October last, and which we noticed briefly at the time, has published an answer thereto.* This admirable pamphlet ought to have the effect of diminishing the disquiet which has prevailed of late. It is something snore than an answer to the headlong absurdities of the Quarterly Re- view ; it is a disquisition on the whole subject brought down to the latest date. All that has been written and talked about "La Gloire," has not altered the opinions of the veteran, who has, from the beginning, endeavoured to restrain the eager haste with which men have been prone to write on the subject ; and at the close he formulates his conclusions. We quote them for the bene- fit of the reader.— "Having carefully revised the whole of the experiments detailed in Sec- tion XII., and studiously reconsidered the deductions at which I had ar- rived, I adhere firmly to the first conclusion, that vessels formed wholly of iron are utterly unfit for all the purposes and contingencies of war. I ground that opinion upon the incontestable fact, that a plate of wrought- iron of the beat quality, 6 feet square and 8 inches thick, leaning uponv but not in contact with, immense slabs of granite by which it was sup- ported, was penetrated, cracked, and broken up by 68-pounder shot at GOO and 400 yards' distance, with a charge of 161bs. "Secondly, I maintain that no ship has yet been produced capable of re- sisting the penetrations and impacts of heavy shot, fulfilling at the same time all the requirements which a sea-going vessel must possess. "Thiedly, I have examined the construction, and considered the results of the experiments tried against Mr. Jones's angular iron-plated ship, and have shown that such a vessel would be washed over by a heavy sea, could have no rigging, on account of the deflection of the shot striking her an- gulated sides, and from the same cause, would imperil those she was in- tended to defend.

"Fourthly, I have closely examined, considered, and computed the weight of material in Captain Coles's scheme, for remedying the defects in that of Mr. Jones, by placing the armament in revolving towers, and shown its impracticability. "And lastly I assert, on information on which the reader may rely, that La Gloirc fregate blindee is a failure as a seagoing ship—that she is really nothing more than a batterie flottante upon a large scale, so burdened with the weight of armament, and loaded with 820 tons of armour-plates, that she is riot capable of ocean-service.

"Raving fully, carefully, and dispassionately considered all these facts and circumstances, I can arrive at no other conclusion, than that all the at- tempts that have been made in France, and by countervailing measures in England, to render iron-cased ships fit for ocean service, either as cruisers, or as types for an ocean fleet of iron-cased vessels, have so far proved abor- tive."

For the evidence upon which Sir Howard relies, we refer the reader to the pages of the Postscript. But we may set forth one or two points which will serve to show how careful we should be in accepting sweeping statements, put forward by any one having the outward air of an authority. Of all the letters which helped to fan the flame of alarm, that of Captain Halsted to the Times contributed the strongest blast. Yet it was full of errors. Cap- tain Halsted said, that "of the three shots fired from Mr. Whit- worth's 80-pounder rifled gun at Shoeburyness at the Trusty,' only one entered the ship." Yet the facts are, that not three but four shots were fired at the ship, and that each shot or bolt ac- tually entered and damaged her side ! Again, Captain Halsted stated, that old age had brought the ships upon which experi- ments were made at Portsmouth to the verge of the breaking-up dock. "He leads his readers to infer," writes Sir Howard, "that the experiments were made against plates hung to the sides of ships ready to tumble to pieces; but knowing something of this matter, I venture to say, that neither of these allegations is cor- rect. Roth the ' Alfred ' and the Sirius' were very far from being in such a state. No ship in Portsmouth Ordinary could have been sounder in planking and timbers than the 'Alfred.' The plates were firmly bolted to the sides." We have no desire to impugn the veracity of Captain Halsted; we only wish to * "A Postscript to the section on Iron Defences, contained in the fifth edition of Naval Gunnery,' in answer to the erroneous principles set forth by the Reviewer in the Quarterly Review for October, 1860. By General Sir Howard Douglas, Bart., &c." Published by Murray. I show how easily even professional men are led to write upon im- perfect data; and upon what unfounded statements the public are alarmed. Again, the Quarterly Reviewer predicts that iron only will soon be used for sea defences against ships, whereas it has been proved by actual experiment in the United States and , in England, that nothing could afford a less effectual protection than iron, except iron and granite, the very combination ap- plauded and recommended by the reviewer.

Then, there is La Gloire. She has been praised for every quality a ship should possess. She is invulnerable to begin with ; she is very fast ; she behaves handsomely in heavy weather ; her masts and rig are perfection. She is so successful that she is to have a score of sisters. Yet what says Sir Howard Douglas, who rightly says that he knows "as much of the real state of foreign navies as any man living," and who speaks on information satis- factory to him ? He says-

" I assert that La Gloire is a failure ; that she is so overloaded with ar- mour and armament, that in anything like heavy seas, she not only takes

water into her ports, but that the sea rolls up her sides and over her ; that she pitches very heavily in a head swell from want of buoyancy to ride over it, as might be expected from being heavily loaded with armour at the bow and stern, where the weight is not supported by displacement directly under it, but mainly by longitudinal strength ; that her speed has never realized anything like that which was expected ; for that, instead of being 131 knots, it has never much exceeded 11, although in her experimental trips, she has

not had upon her all the weight that would he required for service except- ing coals, of which she can only. stow sufficient for seven days' steaming; that she could not fight her main-deck guns in a sea in which our first- class frigates would be comparatively at rest ; and that, therefore, La Gloire is a very bad gunnery ship, her rolling motion being great and quick, so as

in a great degree to vitiate the precision of her rifled guns. When launched and fitted for sea, it was found that she did not carry her guns quite six feet above the water, and she was very deficient in stability. I require not to be told this—it is demonstrable."

We think that Sir Howard amply makes out his case. If we cannot make a sea-going fleet of iron-cased men of war, if they are almost useless for defensive purposes on our coasts and in our harbours, because liable to be found in an unserviceable state just when they are wanted, why construct any more until we have at

least amply tested those the Admiralty have been frightened-and

bullied into building ? "I believe," says Sir Howard Douglas, "that we are acting against the laws of nature by putting iron to an use for which it is unfit ; " and he adds, "I think the iron mania, which is subsiding here, will lapse in France ; and I should not be surprised that ere long lea fregates blindees of 1860 will be as much forgotten as lea vaisseaux cuirasses en fer of 1824 are now." We are afraid the mania is more tenacious of life, and that the iron interest at least will not so willingly let it die.

There is one feeling, too, that will help to sustain its vitality. "For God's sake keep out the shells" was the exclamation of a naval officer ; and the public, on being told that the explosion of a shell in a ship's timbers was sure to convert her into heifer, matches, reciprocated the prayer. Thin plates of iron will keep out the shells, but then they will not keep out the solid shot, even , at long ranges; and thus we are led to the heavy armour plates, four or five inches thick, which now encumber ships of mail. Heavy plates, however, involve an additional weight that destroys the sea-going qualities and velocity of the ships in armour, be- cause " metallic protection and power of speed are antagonistic

qualities." But then the heavy armour plates do comply with the officer's prayer, and "keep out the shells." Before we sacrifice speed and handiness to protection from shells, we ought to look snore calmly upon the actual effects of shells upon timber ships. There are on record two modern real service experiments of shell firing upon ships—the affair at Sinope and the naval attack on Sebastopol. At Sinope, the time-fuze shells of the Russian fleet burnt the Turkish squadron. That would seem con- clusive. It is not. The timber ships before Sebastopol were re- peatedly set on fire by shells, yet not one was destroyed. The only ship that was compelled to withdraw from the fight was the "Queen," and she was set on fire, not by shell, but by a red-hot shot! It was the same with the French ships. They were set on fire, but they were not destroyed. And why ? Because precau- tions were taken, before going into action, to have at hand means of readily extinguishing fire. This fact accounts for the difference between the fate of the Turkish and the allied squadrons. The Turks did not provide means for putting out the fire' and they fell into a panic for this and other reasons. It does not follow, there- fore, that shell firing will be so destructive as a priori might be supposed; and although it is desirable if possible, to keep out the shells, it is not desirable to do so at the expense of so many other qualities a ship of war should possess, and notably speed. We agree with Sir Howard Douglas that "British seamen would dread no danger from shells and particularly from the rare occur- rence of a time-fuse shell taking full effect upon a ship in hori- zontal firing, provided she had speed to carry them into close action, instead of being screened under the shelter of the iron sides of a slow vessel; and it is defamatory of British seamen to say that they would prefer the shelter of the iron sides of a slow vessel, which would compel them to an action oflong.bowle an& distant firing, and deprive them of the power of being brought into close and terminal struggle with the foe, which was their wont of old, and will ever be the characteristic of British 'sea- men."