624 



NAVY, UNITED STATES. 



and with the solid plates, as their thickness is 

 increase^ this source of weakness will be ag- 

 gravated in a degree in which it is not with 

 armor of many thin plates. Thick plates im- 

 part no strength to the ship, nor do they help 

 to strengthen each other, hut in fact hang 

 separately as so many loads on the ship's sides, 

 constituting again by their weight a source of 

 of strain and weakness. Thus, the Duke of 

 Somerset, in the House of Lords, in the early 

 part of 1862, admitted, and the statement holds 

 equally true of all English armored ships built 

 up to this time, " We have not yet constructed 

 a vessel in which the iron plating adds to or 

 assists in constituting the strength of the ves- 

 sel." "A series of thin plates," however, as Mr. 

 Holley remarks, " breaking joints and bolted 

 through the backing, not only fasten each 

 other, but are in effect a continuous girder ;" 

 and in this way, they not only afford support 

 to each other, but strengthen the entire hull 

 at the same time. Meanwhile, laminated ar- 

 mor is both the cheaper and the more easily 

 put on. On the side of solid plates, it has been 

 urged that if the resistance practically does in- 

 crease as the square of thickness, and 4, and 

 5-inch plates are found to tax severely the 

 powers of the best ordnance, then in plates of 

 8 inches thickness is probably to be found a 

 positive protection against the most powerful 

 guns that can be constructed. Supposing this 

 could with such plates be the result, the facts 

 already presented appear to throw doubts, if 

 not upon the feasibility of constructing them 

 of good quality throughout, at least on that of 

 securely and satisfactorily applying them. 



In respect to the use or disuse of a wood 

 backing for the plates, 'it may be stated that 

 while English opinion and practice decidedly 

 favor the armoring only of iron ships and 

 this, in spite of the recent efforts of the Ad- 

 miralty to get the surplus wood in the ship- 

 yards used up in a certain number of wooden 

 hulls, there are those interested in the sub- 

 ject in that country, who argue in favor of 

 armoring with iron on iron, dispensing with 

 the intermediate wood. Among the advocates 

 of this plan has been Prof. Fairbairn, who 

 urged that while a wood backing by its elas- 

 ticity and yielding softened the blow of a pro- 

 jectile, this was done at the expense of the 

 plate, since the latter would be more deflect- 

 ed and driven into the wood. But in all the 

 firing upon the laminated armor of the Moni- 

 tors which has yet taken place, no such result 

 of a broad area of the plating being perma- 

 nently bent and compressed into the backing 

 has occurred. Fairbairn admits, however, that 

 with iron on iron there is greater risk that the 

 result of two or more heavy shot or of a well- 

 concentrated fire might be not only to pene- 

 trate the plates, but also to break the ribs of 

 the ship ; and from results of the very latest 

 experiments with the 300-pounder gun, he con- 

 cludes that some softer and more compressible 

 substance than iron between the armor and 



sides is necessary, in order to deaden the blow; 

 so that the wood backing cannot be dispensed 

 with. This action in the way of distributing 

 and softening the blow upon the hull and ribs 

 of the vessel, as well as upon the armor, ap- 

 pears to be the true function of the wood 

 backing, so that while it adds little to the real 

 strength of armor, it adds greatly to the pro- 

 tection of the ship, and may be considered as 

 generally indispensable. And again, though 

 such backing is subject to the disadvantage of 

 being fired by shells, it becomes a special and 

 important protection of the ship's crew and 

 force, by arresting or preventing the discharges 

 of iron splinters, otherwise so likely to be driv- 

 en into the interior. 



Extent of Armor, and Plans of Armored Ves- 

 sels. As American practice in constructing ar- 

 mored vessels has thus far favored moderate or 

 comparatively small dimensions, so it has tend- 

 ed most strongly to the plan of complete and 

 nearly uniform protection of the entire hull, to 

 a depth below which penetration becomes very 

 unlikely. The French and English practice, 

 directed chiefly to sea-going vessels, and hence 

 of generally large dimensions, has been divi- 

 ded, but in good degree, it would appear, driv- 

 en through the desire of preserving speed 

 to the plans of partial armoring, as previously 

 described. With ships of large size, it appears 

 quite evident that and especially as against 

 the most recent styles of guns and projectiles 

 armor from stem to stern, and of a thickness 

 to be invulnerable, is a thing utterly impracti- 

 cable, at least without such a weight of metal 

 as to sacrifice all desirable manageableness and 

 speed. Besides, it is argued in England that, 

 while the complete mailing of the Royal Sov- 

 ereign, Prince Albert, and others, as intended 

 for coast defence is well enough, vessels mailed 

 on this plan could not properly lift their loaded 

 ends in a heavy sea, so that these must in such 

 case continually be submerged by the waves. 

 Consequently, for large sea-going vessels, a suf- 

 ficiently armored casemate, or turrets, amid- 

 ships, with a broad belt of armor at the water 

 line, a shot-proof deck being formed at the 

 upper level of this armor belt or at water line, 

 the hull being as much as practicable divided 

 into compartments severally water-tight, and 

 with pumping engines and pumps of good ca- 

 pacity within the protected space such, keep- 

 ing in view sea-going qualities, celerity of 

 turning, and speed, appears to be in brief the 

 general plan indispensable to securing at once 

 any sufficient degree of practical invulnerabili- 

 ty and fair chances of keeping afloat. Since 

 there must somewhere be a shot-proof deck, 

 the placing of this near water line does not in- 

 crease the weight of the hull, though it may 

 have some effect on its stability ; but it saves a 

 considerable weight of metal from the unar- 

 mored parts, a portion of which can well be 

 used to strengthen the armor where applied. 

 Again, it has been proposed, with hulls of _the 

 ordinary height out of water, to save weight 



