sweep the race from being in a day, the time will come when two men will alone survive of all the human race. Two men will look around upon the ruins of the workmanship of a mighty people. Two men will gaze upon the tombs of the human family. Two men will stand petrified at the sight of perhaps a hundred thousand corpses prostrated around them by the dire hardships which every moment threaten to carry them also away. These two men will gaze into each other's faces-wan, thin, hungry, shivering, despairing. Speech will have deserted them. Silent, gazing each into eternity-more dead than living-an overpowering emotion-an inspiring hope-and one of them drops by the feet of the sole survivor of God's intel ligent race.

Who can say what a tide of reflections will rush for an instant through the soul of the last man? Who shall listen to his voice, if he speaks? On whose ear shall fall the accents of his sorrow, his wonder, or his hope? Thrice honored, thrice exalted man! He stands there to testify for all mankind. On him has been devolved the unique duty of uttering the farewell of our race to its ancient and much-loved home. In what words will he say farewell?

The last man has composed his body to eternal rest. The once fair earth is a cold and desolate corse. Nature's tears are ice; she weeps no more. The face of the sun is veiled. It is midnight in the highways of the planets. The spirits of heaven mourn at the funeral of Nature.

Let not the reader be distressed at this picture. The last two men will be neither our children nor our children's children. Our thoughts have been wandering through cycles of years. The clock of eternity ticks not seconds, but centuries. We shall not anxiously measure the sun's intensity from day to day, nor from year to year, lest we be able to discover his waning strength. The embers of a

bonfire will furnish warmth for the lifetime of an ephemeron. A molten lava-stream consumes a hundred years in cooling. The great globe of the earth, which is cooling now at the rate of a degree in thirty-five thousand years, was once a sphere of molten granite, and has consumed time enough to pass from that state to this. The sun is so vast that, though he began to cool at a still remoter epoch, the temperature retained to-day is 46,000 times as high as that of the surface of our planet. The epoch when his rays will be sensibly weakened is at a distance expressed by millions of years.

What thoughts rise upon us as we utter these words! We hang here upon our planet, poised in the midst of infinite space and infinite time. Whence we came, we know not; whither we are bound, hope and faith only can reveal. We open our eyes for a moment, like an infant in its sleep, and anon they are closed; or, perchance, like the waking somnambulist, in his fall from the house-top to the pavement, we rouse to an instant's consciousness of the rush of events and the coming crash-and the busy activities of Nature move on as if we had not existed.

A few days since, a friend of mine exhibited to me a silver coin dug up from the rubbish of the hoary East. It was rude, irregular, and begrimed with age. Upon one side was raised the image of a Grecian warrior. Above the head I could trace, with difficulty, but with certainty, the Greek letters which spelled the name of Alexander. Venerable coin! thought I; and my imagination wandered back through twenty-three centuries, till I saw the Issus and the Granicus, and the hosts of Darius melting before the fury of the Macedonian conqueror. I felt transported back to antiquity. But then I remembered the Nineveh marbles upon which I had gazed, and the black and skinny mummies that had looked out at me from their withered

eyeballs, and imagination spanned another interval of ages; and I stood upon the banks of the Tigris and the Nile, and the forms of Sennacherib, and Menes, and Mõses passed before me. As chance would have it, I returned, and, passing through a cabinet where the "medals of creation" had been ranged in regular order, the ponderous molars of an extinct mammoth, dug from the soil of Michigan, awakened a new thought. By its side rested the skull of Oreodon, with its sheep-like teeth in a hog-like head; and, being in a mood for revery, I thought of the distant Missouri plains where Oreodon had grazed; and of the vast lake--thrice the size of Superior-from whose water he had drank, and on whose muddy banks had crawled turtles that could carry oxen on their backs. And then I remembered that thought had darted back over another stretch of ages to a time when God had not yet said, “Let us make man,” when the wide continent was the pasture-ground of elephants, and mastodons, and wild horses, and camels, and sloths, and quadrupeds of strange shapes which were blotted out of existence before ever human eye had gazed upon them.

Here, I thought, are the relics of a genuine antiquity. I sauntered on, and the teeth, and vertebræ, and dimly-outlined forms of Ichthyosaurs, and Deinosaurs, and flying lizards, and fishes clad in mail--bucklered and helmeted fishes -these in succession passed before my eyes. And then winged thoughts flew back through those dim ages of the world's history which we call Mesozoic. I breathed a stifling atmosphere; tepid vapors rose all around me; strange foliage fringed bayous of which I had never heard; neither bird nor insect stirred the fervid atmosphere; there were no forests; the continents were but just arising from their sea-couches, and no footprint had yet been impressed upon their slime-covered heads. And then I thought again of

the silver coin which bore the image and superscription of Alexander, and wondered why I had called it venerable. Why? since twenty populations had possessed the earth, since the relics of those bucklered fishes had been animate, and this coin-why, it had been stamped in the last part of the lifetime of the twentieth population; and there were nineteen before it which had become extinct.

And so my feet were lifted up from earth; I was pillowed upon a bright cloud, and floated in eternity. And I saw the long history of the world I had left stretching backward from the spot where I had left it, till it vanished from view, like the track of a railroad on the boundless prairie. With the flash of a thought, I pursued it over millions of ages, till I saw it dissolved in fire-till luminous vapors rolled up and rested upon the bosom of infinite space. In this cloud of fire the track of terrestrial history lost itself, and I dared not plunge through the flame in search of a beginning.

Then I thought, here at length is the dwelling-place of antiquity. What is this which men call ancient and venerable? Would that the scales could be removed from our eyes! Would that the fog would lift, and men could once look out upon the magnitude of the universe-the majestic span even of terrestrial history-the might, the greatness, the wisdom, the glory of that Intelligence which, at a glance, takes in all space, all time past, and all time to come!

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CHAPTER XXXIX.

THE MACHINERY OF THE HEAVENS RUNNING DOWN.

ET the earth have frozen; let the bright sun have been extinguished; let the moon and stars "wander darkling in the eternal space." Will this, then, be the end of matter's history? Is this the consummation of which philosophers, and poets, and patriarchs have dreamed and prophesied? From the pinnacle on which we stand we can discern the course of Nature still wending onward. There must be progress even after the funeral of the sun. As that bright luminary shines on after the fall of generations of men-as he shines serenely and undisturbed even in dead men's faces, so will gravitation continue to prosecute its work even among the corpses of planets and suns.

Hark! from the highways of the comets come tidings of friction in the machinery of the heavens. The filmy wanderer encounters resistance in his long journey to the confines of the solar system. He plows his way through a resisting medium. The balance of centripetal and centrifugal forces is destroyed; the central attraction preponderates; he falls toward the sun; his orbit is diminished; his motion is accelerated, and he comes back to his startingpoint earlier than the time which astronomy had appointed. Here we get the first disclosure of the existence of a subtile material fluid pervading space.

This remarkable retardation was first observed in the successive returns of Encke's comet. This comet has at present a period of about 1210 days, and it returns each time two hours and forty-five minutes sooner than calcula