Nor are these the only interesting features in the bearing of the American people at the present crisis. Perhaps a still more remarkable one is the entire devotion of the national energies--of intellect not less than of heart, of skill, not less than of capital--to the great purposes of the war. This was the necessary result of our free institutions; of our untrammelled pursuits; the mobility of our means and agencies of production; and the plastic character of all our creations. The amount of thought expended on this subject has been prodigious and incalculable. It would be difficult, if not impossible, to enumerate the ten thousand inventions and devices of all kinds which have been presented for the purpose of increasing the efficiency of weapons and of all the appliances of war, as well as for adding to the comfort and securing the health of the soldier. Every imaginable instrument of usefulness in any of the operations of the camp, or the march, or the field of battle, has been the subject of tentative ingenuity, such as none but Yankees could display. The musket, the carbine, the pistol, have been constructed upon numberless plans, apparently with every possible modification. The cartridge has been covered with copper, impervious to water, instead of paper, and has its own fulminate attached in various modes. Cannon shot and shells have been made in many new forms; and cannons themselves have been increased in calibre to an extraordinary size with proportionate efficiency, and have been constructed in various modes and forms never before conceived. The tent, the cot, the chest, the chair, the knife and fork, the stove and bakeoven, each and every one of them, have been touched by the transforming hand of homely genius, and have assumed a thousand unimaginable forms of usefulness and convenience. India rubber and every other available material have been made to perform new and appropriate parts in the general work. The result of all this unexampled activity and ingenuity has not yet been fully eliminated. It would require years of experience in war in order to bring American genius, as at present developed, to bear with all its extraordinary force on the mechanical details of the military art. Beyond doubt, numberless devices, among those presented, will prove to be utterly worthless; but many of them will certainly stand the test of experience, will be ultimately approved and adopted, and will remain as monuments of the enterprise and ingenuity aroused by the necessities of the country in this hour of its sad calamity.