In this rush of development of twenty years it is true that all fleets have been immeasurably strengthened, but it has been at a cost far beyond what the result would warrant. It is only within the past five years that the development of iron-clad architecture can be said to have taken any steady course. As yet the full effects of this forced and feverish course can scarcely be realized; but as fleets grow now slowly and steadily, those nations who have waited a little and profited by the true developments of the more hasty ones will be in a far better position to meet the sudden exigencies of war than those who have counted on numbers of vessels and gross tonnage displacement as a true criterion of naval strength. From the number of cautious nations the United States must be excluded, since in this country the blow given to the development of private ship-building by the civil war and to the development of naval architecture by political intrigue and interference has resulted in the nearly complete destruction of the science itself. Nothing is more common amongst naval people than speculations and arguments with regard to the true methods of developing a fleet, and it is generally taken for granted amongst those who give the subject but a superficial study that, since the designs that have been created are almost countless in their variety, and that amongst those nations that have attempted an independent development there is not one that does not count as many failures as successes, the matter of design is one of pure guess-work, not stopping to think that, as a rule, the designers themselves are men of the highest abilities, and that with a ship, as with everything else, there are certain limiting circumstances that the nature of the vessel itself forbids violating. In this respect a comparison of the proportions of the different elements of vessels of varying types affords a useful lesson. RATIOS OF THE PRINCIPAL ELEMENTS OF IRON-CLAD VESSELS TO THEIR DISPLACEMENT. _First-rate, Sea-going, Full-rigged Frigates._ DISPLACEMENT RANGING FROM 10,500 TO 5400 TONS.