223 Mail- Clad Steamers. [August, or shell distances of three to five miles, which " the wooden walls " of neither England nor America are able to re- O sist We have recently seen the Freeborn, the Pawnee, and the Harriet Lane, when assailing the rebel batteries on the James and the Potomac, compelled to take posi- tions at the distance of two miles, and to keep constantly moving, and compelled consequently to throw away most of their costly ammunition in uncertain shots, at the same time that they were constantly exposed to shots which might destroy their engines and explode their boilers. There was no lack of courage on the part of their gallant officers ; but, from the insuf- ficiency of the vessels, they were obliged to use a wise discretion, and to take all reasonable precautions for the safety of their ships, so important and yet so in- adequate to the service of the country. And when Fort Sumter was about to fall, and when a single shot-proof gun-boat could have defied the rebel batteries, and without the loss of a man have convey- ed to the fortress stores for six months and a whole battalion of troops, that sin- gle gun-boat, a mere gun-boat, which need not have passed within one thou- sand yards of any batteries on her way, could not be commanded by the Gov- ernment, and the gallant Anderson was compelled to lower to treason that flag whose fall has aroused the nation to arms. The earliest experiments upon the power of iron plate to resist the force of cannon-balls appear to have been made in France by M. de Montgery, an officer in the French navy, as far back as 1810. He proposed to cover the sides of ships with several plates of iron, of the aggre- gate thickness of four inches, which he alleged would resist the force of any pro- jectile. But Napoleon had not confi- dence in his navy ; he had lost the bat- tles of the Nile and Trafalgar ; ever suc- cessful on the land, his ships had been swept by Nelson from the deep ; and he had neither time nor disposition to inves- tigate new plans for the restoration of the navy, or even to take up Fulton's new discovery. It was reserved for the third Napoleon to develop the original idea of a Frenchman, and thus to place France on the sea nearly or quite upon a footing with England. Some twelve years later, General Paix- hans, who gave his name to the large guns of modern times, (although their prior invention was claimed by the late Colo- nel Bomford,) again commended plate- armor for ships to his Government; but his advice was not then adopted. With the improvement of cannon the importance of plate-armor became more and more apparent ; and at length Mr. Stevens, under the sanction of our Gov- ernment, instituted a series of experi- ments upon iron plates, and soon after commenced building an immense float- ing battery for the defense of New York, at Hoboken, which is still unfinished, but which, it is rumored, will, if Congress ap- propriates the means, be completed the present season. Stevens was the first to carry out the idea of a mail-clad steamer ; and it is alone due to the apathy of the late Ad- ministration, which has neglected our na- vy while indulging in its Southern pro- clivities, that our nation has not the hon- or of launching the first steamer in a coat -of- mail. The frame, however, of such a vessel has been long in place, the hull is nearly complete, the engines are far advanced, and the finishing stroke may soon be given. Stevens, in the course of his experi- ments, made the important discovery, that a single plate of boiler-iron, five-eighths of an inch in thickness, and weighing less than twenty-five pounds to the superficial foot,* when nailed to the side of a ship, was impenetrable by shell and red-hot shot, the two missiles most dangerous to wooden walls. When a solid shot strikes the side of a wooden ship, it passes in and usually stops before it reaches the oppo- site side. The fibers of the wood yield and close up behind it, and it often hap- pens, from the reunion of the fibers, that
- Sheet-iron plates of one inch in thickness
weigh forty pounds per superficial foot.
