Superior, in 1858, were thirty thousand five hundred and twenty-seven tons; in 1859, eighty thousand tons; in 1860, one hundred and fifty thousand tons.  So great are the magnetic powers of this iron, that, buried as it was in the depths of the forest and beneath the surface of the earth, it disturbed the compasses of the United States surveyors while engaged in the survey of Northern Michigan.  For a time their needle would not work, and they were obliged temporarily to suspend their operations.  Their embarrassment led to the discovery of these vast deposits of ore.  It is now mingled with the inferior ore of Ohio and Pennsylvania, and extensively wrought.

Our nation has strong motives to induce it to construct an iron navy.

First. The adoption of such a navy by the great powers of Europe,—­England and France,—­followed by Russia, Austria, and Spain.  Our commerce will be in danger, if they once acquire the power of assailing us with impunity.

Second. Our urgent want of this class of vessels to recover our fortresses, repel blockades, and reopen our Southern ports, without wearisome sieges, costly both in blood and treasure.

Third. Our inability to command our customary supplies of durable timber.

Fourth. The abundance of iron, unrivalled in any part of the world.

Fifth. The durability of the ships constructed from iron.  If well manned and piloted, they will seldom need repairs; and instead of failing, as many ships do in the sixth year, and requiring vast expenditures to discharge and dismantle them for the renewal of the decaying timber, plank, copper, and other materials, often amounting in the aggregate to more than their original cost, the mail-clad steamers built of American iron will outlive successive races of wooden steamships.  The iron such a navy would require will put many idle hands in motion, which would otherwise be unproductive during war,—­the miners of Michigan, Ohio, Pennsylvania, and New York, the colliers of Ohio and Pennsylvania, the mariners of the Lakes, the navigators of canals, and the operatives of railways, down to the brawny smiths who fashion the metal into shapes,—­until their combined efforts launch it upon the deep, and send it forth to

  “dare the very elements to strife.”

How much better would it be to create such an iron navy than to expend million after million on wooden walls that must soon perish by decay or the shells of the enemy, or to lavish three or four millions upon the conversion of our superannuated ships-of-the-line into steamships!  These, when converted, will still retain their age and constant tendency to decay, their models long since abandoned, their original design, height of decks, and other proportions adapted to the eighteen- and twenty-four-pounders formerly in use, which are now giving place to Dahlgren and rifled cannon carrying balls of sixty-four to one hundred pounds weight.  Such an expenditure would be like an essay to convert a Yankee shingle-palace, such as Irving described half a century ago, into a modern villa, and reminds one of a proposition made to an assembly some twenty centuries since, which still has its significance.