Now, if the two systems of winds, with their jars thus filled, were to turn back to their respective hemispheres, and pour down upon them their water, in the shape of rain, the consequence would be, as the reader sees, that we should have less rain in the northern hemisphere, than they would have in the southern hemisphere; whereas, we require more, having more land to be watered. The atmospheric machine would thus be at fault. But the all-wise and beneficent ruler of the universe, makes nothing faulty. We know from the evidence of that silent witness, the rain-gauge, that more water falls in the northern hemisphere, than in the southern; in other words, that the more heavily laden of those jars which we examined; a moment ago, at the equator, have come to us, instead of returning to the south; the less heavily laden jars going south. The crossing of the winds thus satisfies our theory, and nothing else can; which is, of course, the most conclusive. of all proofs.

But we have other proofs. For a number of years past, as the East India ships would be returning home from their voyages, they would report a curious phenomenon to have befallen them, as they passed the parallel of the Cape de Verde. This was the falling, or rather silting down upon their decks and rigging, of a brick-dust or cinnamon-colored powder. This dust, which when rubbed between the thumb and forefinger would be impalpable, would sometimes nearly cover the entire deck and rigging. The ships would be hundreds of miles away from the land, and where could this dust come from? The fact puzzled the philosophers, but having been reported so often, it ceased to attract attention. Still it was a fact, and was laid away carefully in the archives of philosophy for future use. Years passed away, and the great traveller and philosopher, Humboldt, arose to instruct and delight mankind. He travelled extensively in South America; and, among other places, visited the lower valley of the Orinoco. He happened there in the dry season, and gives a graphic account of the wild and weird spectacle of desolation which met his eye in that season of universal drought.

All annual vegetation lay dead and desiccated on the immense pampas or plains. The earth was cracked open, gaping,

as it were, for rain. The wild cattle were roaming about in herds, bellowing for their accustomed food and water; many of them perishing. Even the insect world, so numerous and vivacious in all southern climates, had perished. Their tiny little organisms lay in heaps, fast disintegrating, and being reduced to powder, by the scorching and baking rays of a perpendicular sun, between which and the parched earth, not so much as a speck of cloud appeared. The philosopher examined a number of these little organisms with his microscope. They were peculiar to the region in which he found them, and he was struck with the fact. There was another phenomenon which he observed. A number of little whirlwinds were playing their pranks about the arid waste, sporting, as it were, with dead nature. These little whirlwinds, as they travelled hither and thither, would draw up into their vortices, and toss high into the upper air, the impalpable dust that lay everywhere, and which was composed, in great measure, of the decomposed and decomposing organisms of which I have spoken. The atmosphere, at times, when filled with this dust, would assume a yellowish, or pale straw colored hue.

The reader probably, by this time, sees my design of connecting the dusty remains, described by Humboldt, with the rain dust reported by the mariners to have fallen on the decks and rigging of their ships, in the neighborhood of the Cape de Verde islands. But the "rain-dust" was of brick-dust, or cinnamon color, when collected by the masters of the ships, as specimens, and the heavens, when filled with the dust thrown up by the whirlwinds, as described by Humboldt, appeared to him to be of a straw color. Here is a discrepancy to be rec onciled, and we must call in the aid of another philosopher, Captain M. F. Maury, late Superintendent of the National Observatory, at Washington, before alluded to in these pages, and to whom I am indebted for many of the facts here quoted. Captain Maury was struck with this discrepancy, and in reconciling it with the theory here discussed, makes the following statement: "In the search for spider lines, for the diaphragms of my telescopes, I procured the finest, and best threads from a cocoon of a mud-red color; but the threads of this cocoon, as seen singly in the diaphragm, were of a golden color; there

would seem, therefore, no difficulty in reconciling the difference between the colors of the rain-dust, when viewed in little piles by the microscopist, and when seen attenuated and floating in the wind by the regular traveller."

There remains but another link in the chain of evidence, to render it complete. It remains to be shown how the whirlwind dust, of the valley of the lower Orinoco, can be identi fied with the rain-dust of the Cape de Verde. Ehrenberg, a German philosopher, has done this, in our day. Some specimens of the rain-dust having been sent him by ship-captains, he brought them under his microscope, as Humboldt had done the whirlwind-dust, and to his great astonishment, and delight, he found it to be the same. These facts correspond entirely with our theory of the crossing of the trade-winds at the equator. The reader has been with us near the mouth of the Orinoco. This great river disembogues near the island of Trinidad, which we visited in the Sumter, in about the latitude of 9° N. The vernal equinox is the dry season here, and at this season, the north-east trade-wind is quite fresh. Running counter to this wind, in the upper atmosphere, there is, according to our theory, a strong south-west wind blowing. Now, if the reader will inspect a map, he will find that a south-west wind, starting from the mouth of the Orinoco, will blow over the Cape de Verde islands. The rest is plain. The whirlwind-dust is tossed high enough into the upper atmosphere, to be taken in charge by the counter south-west wind, is carried to the Cape de Verde, and there silted down upon the decks and rigging of the passing ships, as gently as so many snowflakes, becoming the rain-dust which so long puzzled the philosophers!

We have reasoned, hitherto, on the supposition, that the three calm-belts, one of which the Alabama is now passing, and the two systems of trade-winds which they enclose, are stationary within certain limits. But this is not so; the whole system of belts and winds is moved north and south, as the sun passes now into one hemisphere, and now into another. The calm-belt of Cancer is not always in the latitude of 30° N.; nor is the calm-belt of the equator always at the equator. The reader will recollect that we observed, on board the Ala

bama, on the 10th of November, in latitude 25° N., and that we were only just then entering the calm-belt of Cancer. The reason is, that the sun, on that day, was in the southern hemisphere, well advanced toward his extreme limit in that hemisphere, and that he had dragged, as it were, the whole system of belts and winds after him. The figures below will make this idea plain. Let the broad, dark lines in the circles represent the system of belts and winds, all in one; and in circle A let the sun be in the northern hemisphere, and in circle B let him be in the southern.

The reader will see, how the sun, having hitched this system of belts and winds to his chariot wheels, as it were, has drawn it after him. The distances north and south, to which they have been drawn, are exaggerated in the figures, but this is only for the purpose of better illustration. The reader will see, from this diagram, how much farther South the Alabama will have to run, in November, to catch the north-east tradewind, than she would have had to run in May. We may now return to our ship, and our cruise, and when I shall mention the trade winds and the calm-belts, hereafter, the reader will not, I hope, regret the time I have consumed in refreshing his memory on so interesting a subject. We spoke several English vessels after burning the Wales, and a couple of them, bound to Demerara, kept company with us through the calm-belt. We sent a boat on board one of them, from New York, but she

had neither news nor newspapers. At length, when we had reached the parallel of about 20°, we began to receive the first gentle breathings of the trade-wind. Our light sails aloft began first to "belly out," and then a topsail would fill for a moment, until the ship rising. on the gentle undulations of the sea, and falling again, would flap the wind out of it. The zephyr-for, as yet, it was nothing more-visibly gained strength, however, from hour to hour, and on the 16th of November, I find the following record in my journal: "Beautiful, clear weather, with a moderate trade-wind, from about east by south, and the well-known fleecy trade-clouds sailing leisurely over our heads."

It is Sunday, and muster-day, and the Alabama has once more been put in perfect order. She has had a coat of paint, inside and out, her masts have been freshly scraped, and her rigging re-rattled, and tarred down. Her guns are glistening in the new coat of "composition" which the gunner and his mates have put upon them; her engine-room is all aglow with burnished brass and steel; her decks are white and sweet, and her awnings are spread. The muster is over, the men are lying listlessly about the decks, and our lady passengers are comfortably seated on the quarter-deck, with several of the young officers around them, and with the children playing at their feet. Such was the contrast which the Alabama presented, on that quiet Sabbath day, with her former self only a few weeks back, when we had been rolling and tumbling in the Gulf Stream, with crippled yards, torn sails, and her now bright sides seamed and defaced with iron-ruse from her corroding chains.

We were soon ready to go into port-our first port since leaving Terceira. Men and officers were all desirous of a little relaxation, and were pretty soon on the look-out for land. On the next day, at two P. M., we made the island of Dominica-the same Dominica that lay so fast asleep in the gentle moonlight, on the night that the little Sumter ran so close along it, like a startled deer, after her escape from the Iroquois. We were returning to our old cruising-ground, after an interval of just one year, in a finer and faster ship, and we cared very little now about the Iroquois, and vessels of her class. Having doubled the