The Navy Department has recently put under contract seven steamships and several steam gun-boats.  They have intrusted the latter to some of the ablest ship-builders of the country, and it is well understood that most of these vessels are to be completed the present season.  This measure, as far as it goes, is eminently wise; but our navy must still be below the requirements of the nation, and entirely disproportioned to the extent both of our commerce and of our sea-coast.  At a low estimate, our country requires an additional supply of at least six mail-clad steam frigates, twelve steam sloops-of-war, and twelve steam gun-boats, with similar armor.  It will require also for long voyages and distant stations a dozen steam frigates of wood, and as many steam sloops-of-war, like the best now in our service; and, with the materials and armament now on hand, an outlay of twenty-five or thirty millions well applied may suffice for the construction of the whole.  With such a provision we need feel no solicitude as to the intervention of England or France in our domestic affairs.

The lighter steamships of wood will answer for long voyages to the Mediterranean, the coast of Africa, India, and the Pacific, and will protect our grain, flour, and corn, on their way from the West to Europe.  Our iron steamers will defend our commercial cities from attack or blockade; they will level all rebel batteries on the waters of the Chesapeake; they can batter down the fortresses of the Southern coast, and restore to commerce the ports of Charleston, Savannah, Pensacola, Mobile, Apalachicola, New Orleans, and Galveston.

Most fortunately for our country, at a moment when we cannot immediately command the live oak of Georgia and Florida, the oak plank of Virginia, or the yellow pine of the Carolinas, we have the most abundant supplies of iron easily accessible, and now, relieved from the demands of railways and factories, ready for the construction of our iron navy.  The iron plates of Pennsylvania and Maryland in strength and toughness know no superior.  The iron mountain near St. Louis and the mines on Lake Champlain furnish also an article of great purity and excellence.  But, choice as are these deposits of iron, they are all surpassed by the more recent discoveries on Lake Superior, now opened by the ship-canal at the Straits of St. Mary.  There Nature has stored an inexhaustible amount of the richest iron ore, free from sulphur, phosphorus, arsenic, and other deleterious substances, protruding above the surface of hillocks and underlying the country for miles in extent.  This ore is of the specular and magnetic kind, yields sixty-five per cent. of iron of remarkable purity, is easily mined and transported to the Lake, and is shipped in vast quantities to the ports of Lake Erie, where it meets the coal of Ohio.  At least ten companies are now engaged in its shipment, which has progressed thus far with great rapidity, doubling every year.  The shipments from Lake