IV. Nor has the atmosphere—that twin ocean of upper earth—failed to give evidence of the properties and laws by which it was then governed. The RAIN-DROP, a singular unmistakeable marking, has also been detected upon the sandstones of the period. These impressions have been described and adopted by men of science as the true veritable indices of the showers and cloud-falls of the old world. The very size of the drop may be measured, the thick pattering of the rain compared with the scanty or copious showers of the present day, and the very point detected from which the wind blew on the day that these showers fell. What a curious tale is thus disclosed, by a record, no modern version of which any one will stay to read a moment longer than he can escape to shelter from its influences. Astronomers tell us, upon the faith of the Herschels, the measurements of Strüve, Bessel, and Mädler, that, notwithstanding that light travels at the inconceivable speed of two hundred and thirteen thousand miles in a second, the light from Uranus, one of our own planetary system, does not reach our earth until two hours after it has been emitted from its orb; that, from the edge of the Milky Way, a star of the twelfth magnitude, careering in all the effulgence of that luminous ether, cannot be descried until four thousand years after the ray has begun its journeyings; and yet more, as the results of the most rigid induction, it is revealed to us that the spots of clouds, which under the resolving power of the best telescopes seem more oval flakes or small specks of whiteness, are really distinct and independent systems, floating at such an immeasurable distance that the light has to wander millions of years before it can break in its faintest morning-streak upon our horizon. Mark the analogy, therefore, ere you scoff at the credulity of the geologist, or the power of the rain-drop to transmit an image of itself through so many revolutions and ages of the earth’s history. How impalpable a substance is light! how readily effaced its impressions, or intercepted its brilliant colorings, by the interposition of the frailest creation of matter—an insect’s wing, the covering of a leaf, the disc of a flower-petal. But the light, thus easily obliterated or dimmed on earth, has been maintaining its own solitary independent course through every medium, every change, of upper and netherworlds. The moment of its efflux from remotest orb, in depth of infinite space, gave to every particle of that feebly or intensely luminous beam, a separate being and direction, with no return back to its parent source. And now, says the intelligent astronomer, as it drops gently into the searcher of his telescope, that is a ray from yon far distant unresolvable cluster of stars, or of astral systems, for millions of years traveling through these incalculable heights, when as yet the Chaldee sages had pointed no instrument to the heavens, nor the learned of Memphis recorded an observation.