been added, new principles evolved; ponderous engines, like moving mountains of iron, shake the very earth; many-windowed factories, filled with complex machinery driven by water or its vapor, clatter night and day, weaving the plain garments of the poor man and the rich robes of the prince, the curtains of the cottage and the upholstery of the palace.

Once there were but the spear and bow and shield, and hand-to-hand conflicts of brute strength. See now the whole enginery of war, the art of fortification, the terrific perfection of artillery, the mathematical transfer of all from the body to the mind, till the battlefield is but a chess-board, and the battle is really waged in the brains of the generals. How astonishing was that last European field of Solferino, ten miles in sweep,—with the balloon floating above it for its spy and scout,—with the thread-like wire trailing in the grass, and the lightning coursing back and forth, Napoleon's ubiquitous aide-de-camp,—with railway-trains, bringing reinforcements into the midst of the melée, and their steam-whistle shrieking amid the thunders of battle! And what a picture of even greater magnificence, in some respects, is before us to-day! A field not of ten, but ten thousand miles in sweep! McClellan, standing on the eminence of present scientific achievement, is able to overlook half the breadth of a continent, and the widely scattered detachments of a host of six hundred thousand men. The rail connects city with city; the wire hangs between camp and camp, and reaches from army to army. Steam is hurling his legions from one point to another; electricity brings him intelligence, and carries his orders; the aëronaut in the sky is his field-glass searching the horizon. It is practically but one great battle that is raging beneath him, on the Potomac, in the mountains of Virginia, down the valley of the Mississippi, in the interiors of Kentucky and Tennessee, along the seaboard, and on the Gulf coast. The combatants are hidden from each other, but under the chieftain's eye the dozen armies are only the squadrons of a single host, their battles only the separate conflicts of a single field, the movements of the whole campaign only the evolutions of a prolonged engagement. The spectacle is a good illustration of the day. Under the magic of progress, war in its essence and vitality is really diminishing, even while increasing in materiel and grandeur. Neither time nor space will permit the old and tedious contests of history to be repeated. Military science has entered upon a new era, nearer than ever to the period when wars shall cease.

But to go on with a few more contrasts of the past with the present. Once men wrote only in symbols, like wedges and arrow-heads, on tiles and bricks, or in hieroglyphic pictures on obelisks and sepulchres,—afterward in crude, but current characters on stone, metal, wax, and papyrus. In a much later age appeared the farthest perfection of the invention: books engrossed on illuminated rolls of vellum, and wound on cylinders of boxwood, ivory, or gold,—and then put away like richest treasures of art. What a difference between perfection then and progress now! To-day the steam printing-press throws out its sheets in clouds, and fills the world with books. Vast libraries are the vaulted catacombs of modern times, in which the dead past is laid away, and the living present takes refuge. The glory of costly scrolls is dimmed by the illustrated and typographical wonders which make the bookstore a gorgeous dream. Knowledge, no longer rare, no longer lies in precarious accumulations within the cells of some poor monk's crumbling brain, but swells up like the ocean, universal and imperishable, pouring into the vacant recesses of all minds as the ocean pours into the hollows under its shore. To-day, newspapers multiplied by millions whiten the whole country every morning, like the hoar-frost; and books, numerous and brilliant as the stars, seem by a sort of astral influence to unseal the latent destinies of many an intellect, as by their illumination they stimulate thought and activity everywhere.

Once art seemed to have reached perfection in the pictures and sculptures of Greece and Rome. Yet now those master-pieces are not only equalled on canvas and in fresco, but reproduced by tens of thousands from graven sheets of copper, steel, and even blocks of wood,—or, if modelled in marble or bronze, are remodelled by hundreds, and set up in countless households as the household gods. It is the glory of to-day that the sun himself has come down to be the rival and teacher of artists, to work wonders and perform miracles in art. He is the celestial limner who shall preserve the authentic faces of every generation from now until the world is no more. He holds the mirror up to Nature, paralyzes the fleeting phantom, by chemical subtilty, on the burnished plate,—and there it is fixed forever. He prepares the optical illusion of the stereoscope, so that through tiny windows we may look as into fairy-land and find sections of this magnificent world modelled in miniature.

Once men imagined the earth to be a flat and limited tract. Now they realize that it is a ponderous ball floating in infinite ether. Once they thought the sky was a solid blue concave, studded with blazing points, an empire of fate, the gold-and-azure floor of the abode of gods and spirits. Now all that is dissolved away; the wandering planets become at will broad disks, like sisters of the moon; and countless millions of stars are now mirrored in the same retina with which the Magi saw the few thousands of the firmament that were visible from the plains of Chaldea.

Once men were aware of nothing in the earth beneath its hills and valleys and teeming soil. Now they walk consciously over the ruins of old worlds; they can decipher the strange characters and read the strange history graven on these gigantic tablets. The stony veil is rent, and they can look inimitable periods back, and see the curious animals which then moved up and down in the earth.

Once a glass bubble was a wonder for magnifying power. Now the lenses of the microscope bring an inverted universe to light. Men can look into a drop and discover an ocean crowded with millions of living creatures, monsters untypified in the visible world, playing about as in a great deep.

Once a Roman emperor prized a mysterious jewel because it brought the gladiators contending in the arena closer to the imperial canopy. Now observatories, with their revolving domes, crown the heights at every centre of civilization, and the mighty telescope, poised on exquisite mechanism, turns infinite space into a Coliseum, brings its invisible luminaries close to the astronomer's seat, and reveals the harmonies and splendors of those distant works of God.

Once the supposed elements were fire, and water, and earth, and air; once the amber was unique in its peculiar property, and the loadstone in its singular power. Now chemistry holds in solution the elements and secrets of creation; now electricity would seem to be the veil which hangs before the soul; now the magnetic needle, true to the loadstar, trembles on the sea, to make the mariner brave and the haven sure.

We have by no means exhausted the wonders that have accumulated upon man, in being accumulated by man. Their enumeration would be almost endless. But we leave all to mention one, with which there is nothing of old time to compare. It had no beginning then,—not even a germ. It is the peculiar leap and development of the age in which we live. Many things have combined to bring it to pass.

A spirit that had been hid, since the world began, in a coffer of metal and acid,—the genie of the lightning,—shut down, as by the seal of Solomon in the Arabian tale, was let loose but the other day, and commenced to do the bidding of man. Every one found that he could transport his thought to the