“Now o’er their head the whizzing whirlwinds breathe,And the live desert pants and heaves beneath;Tinged by the crimson sun, vast columns riseOf eddying sands, and war amid the skies,In red arcades the billowy plain surround,And stalking turrets dance upon the ground.”—Darwin.
“Now o’er their head the whizzing whirlwinds breathe,And the live desert pants and heaves beneath;Tinged by the crimson sun, vast columns riseOf eddying sands, and war amid the skies,In red arcades the billowy plain surround,And stalking turrets dance upon the ground.”—Darwin.
“Now o’er their head the whizzing whirlwinds breathe,And the live desert pants and heaves beneath;Tinged by the crimson sun, vast columns riseOf eddying sands, and war amid the skies,In red arcades the billowy plain surround,And stalking turrets dance upon the ground.”—Darwin.
“Now o’er their head the whizzing whirlwinds breathe,
And the live desert pants and heaves beneath;
Tinged by the crimson sun, vast columns rise
Of eddying sands, and war amid the skies,
In red arcades the billowy plain surround,
And stalking turrets dance upon the ground.”—Darwin.
In the pathless desert, high mounds of sand, shifting with every change of wind, surround the traveler on every side, and conceal from his view all other objects. There the wind is of a surprising rapidity; and the sand is so extremely fine, that it forms on the ground waves which resemble those of the sea. These waves rise up so fast, that in a very few hours a hill of from twenty to thirty feet high is transported from one place to another. The shifting of these hills, however, does not take place on a sudden, as is generally believed, and is not by any means capable of surprising and burying a caravan while on the march. The mode in which the transposition of the hills takes place is not difficult of explanation. The wind sweeping the sand from the surface continually, and that with an astonishing rapidity, the ground lowers every moment: but the quantity of sand in the air increasing as quickly by successive waves, can not support itself there, but falls in heaps, and forms a new hill, leaving the place it before occupied level, and with the appearance of having been swept.
It is necessary to guard the eyes and mouth against the quantity of sand which is always flying about in the air; and the traveler has to seek the right direction, to avoid being lost in the windings made in the middle of the hills of sand which bound the sight, and which shift from one spot to another so often, as not to leave anything to be seen besides the sky and sand, without any mark by which the position can be known. Even the deepest footstep in the sand of either man or horse disappears the moment the foot is raised. The immensity, the swiftness, and the everlasting motion of these waves when the wind is blowing, disturb the sight both of men and beasts, so that they are almost continually marching as if in the dark. The camel gives here a proof of his great superiority; his long neck, perpendicularly erected, removes his head from the ground, and from the thick part of the waves; his eyes are well defended by thick eye-lids, largely provided with hair, and which he keeps half shut; the construction of his feet, broadand cushion-like, prevents his treading deep into the sand; his long legs enable him to pass the same space with only half the number of steps of any other animal, and therefore with less fatigue. These advantages give him a solid and easy gait, on a ground where all other animals walk with slow, short, and uncertain steps, and in a tottering manner. Hence the camel, intended by nature for these journeys, affords a new motive of praise to the Creator, who in his wisdom has given the camel to the African, as he has bestowed the reindeer on the Laplander.
Lieutenant Pottinger, in his travels in Beloochistan, a province of India, gives the following interesting account of those curious phenomena. He had to pass over a desert of red sand, the particles of which were so light, that when taken in the hand they were scarcely more than palpable, the whole being thrown by the winds into an irregular mass of waves, principally running east and west, and varying in hight from ten to twenty feet. The greater part of them rose perpendicularly on the opposite side to that from which the prevailing north-west wind blew, and might readily have been fancied, at a distance, to resemble a new brick wall. The side facing the wind sloped off with a gradual declivity toward the base of the next windward wave, and then again ascended in a straight line, in the same extraordinary manner as above described, so as to form a hollow or path between them. Our traveler kept as much in these paths as the direction he had to take would allow; but it was not without great difficulty and fatigue that the camels were urged over the waves, when it was requisite to do so, and more particularly when they had to clamber up the leeward or perpendicular face of them, in attempting which they were often defeated. On the oblique or shelving side they ascended pretty well, their broad feet saving them from sinking deeper than did the travelers themselves; and the instant they found the top of the wave giving way from their weight, they most expertly dropped on their knees, and in that posture gently slid down with the sand, which was luckily so unconnected, that the leading camel usually caused a sufficient breach for the others to follow on foot. The night was spent under shelter of one of these sand waves, the surrounding atmosphere being uncommonly hot and close.
On the following day, in crossing a desert of the same description, the like impediments occurred; but these were trifling compared with the distress suffered, not only by our traveler and his people, but also by the camels, from the floating particles of sand; a phenomenon for which he confesses himself at a loss to account. When he first observed it, in the morning, the desert appeared to have, at the distance of half a mile or less, an elevated and flat surface from six to twelve inches higher than thesummits of the sand waves. This vapor appeared to recede as he advanced, and once or twice completely encircled his party, limiting the horizon to a very confined space, and conveying a most gloomy and unnatural sensation to the mind of the beholders, who were at the same moment imperceptibly covered with innumerable atoms of small sand, which getting into the eyes, mouth and nostrils, caused excessive irritation, attended by an extreme thirst, which was increased in no small degree by the intense heat of the sun. This annoyance is supposed by the natives to originate in the solar beams causing the dust of the desert, as they emphatically call it, to rise and float through the air; a notion which appears to be in a great measure correct, this sandy ocean being only visible during the hottest part of the day. The following simple theory of these moving sands is submitted by the author. When the violent whirlwinds which prevail in the desert, terminate in gusts of wind, they usually expand over several square miles of surface, raging with irresistible force, and bearing upward an immense body of sand, which descends as the current of air that gave it action dies away, thus creating the extraordinary appearance in question. If it should be asked what prevents the sand from subsiding altogether, when it has so far accomplished this as to rest apparently on the waves, the answer is, that all the grosser particles do settle, but that the more minute ones become rarefied to such a degree by the heat produced by the burning sand on the red soil, that they remain as it were in an undecided and undulating state, until the returning temperature restores their specific gravity; when, by an undeviating law of nature, they sink to the earth. This in some measure coincides with the opinion of the native Brahoes; but, conformably to their notion, it is evident that the floating sands would be apparent at all periods of excessive solar influence; which not being the case, it becomes necessary to find a primary cause for the phenomenon. To remove any suspicion of his having been deceived in the reality of this floating vapor of sand, he adds that he has seen this phenomenon, and theshurab, or watery illusion so frequent in deserts, called by the Frenchmirage, in opposite quarters at the same moment, each of them being to his sight perfectly distinct. While the former had a cloudy and dim aspect, the latter was luminous, and could not be mistaken for water. To corroborate what he has here advanced, he states that he was afterward joined by a faquir from Kaboul, who informed him that he had witnessed the moving sands, in passing through the desert from Seistan, to a much greater degree than has been described; and, what is scarcely credible, he spoke of having been forced to sit down, in consequence of the density of the cloud in which he was enveloped.
Our traveler next proceeds to a curious description of the pillars orcolumns of sand formed in the deserts. He experienced a violent tornado, or gust of wind, which came on so suddenly, that, if he had not been apprised of its strength by the guide, it might have been disastrous to his party, in whom it would have been an act of temerity to have endeavored to sit on the camels during its impetuous fury. Before it began, the sky was clear, save a few small clouds in the north-west quarter; and the only warnings it afforded, were the oppressive sultriness of the air, and a vast number of whirlwinds springing up on all sides. These whirlwinds, he observes, might perhaps be more correctly expressed by some other name; but as the wind issued from them he adopts the term. They are vast columns of sand, which begin by a trifling agitation, with a revolving motion on the surface of the desert, and gradually ascend and expand, until their tops are lost to the view. In this manner they move about with every breath of wind, and are observed, thirty or forty of them at the same time, of different dimensions, apparently from one to twenty yards in diameter. Those who have seen a waterspout at sea, may exactly conceive the same formed of sand on shore. The moment the guide saw the whirlwinds disperse, which they did as if by magic, and a cloud of dust approaching, he advised the party to dismount, which they had hardly time to do, and lodge themselves snugly behind the camels, when a storm burst upon them with a furious blast of wind, the rain falling in huge drops, and the air being so completely darkened, that they were unable to discern any object at the distance of even five yards.
The following is Bruce’s account of this singular phenomenon, which he represents as one of the most magnificent spectacles imaginable, and by which he and his companions were at once surprised and terrified. Having reached the vast expanse of desert which lies to the west and north-west of Chendi, they saw a number of prodigious pillars of sand at different distances, at times moving with great celerity, and at others stalking on with a majestic slowness. At intervals the party thought they should be overwhelmed by these sand-pillars; and small quantities of sand did actually more than once reach them. Again, they would retreat so as to be almost out of sight, their summits reaching the very clouds. There the tops often separated from the bodies; and these once disjointed, dispersed in the air, and did not appear more. They were sometimes broken near the middle, as if struck by a large cannon-shot. About noon they began to advance with considerable swiftness upon the party, the wind being very strong at north. Eleven of them ranged alongside, at about the distance of three miles from them; and at this interval the greatest diameter of the largest of them appeared to Mr. Bruce to be about ten feet. They retired with awind at south-east, leaving an impression on our traveler’s mind, to which he could give no name, though assuredly one of its ingredients was fear, blended with a considerable portion of wonder and surprise. It was in vain to think of fleeing: the swiftest horse, or fastest sailing ship, would have been of no use in rescuing him from his danger. The full persuasion of this riveted him as it were to the spot where he stood, and he allowed the camels to gain on him so much, that it was with difficulty he could overtake them. On a subsequent occasion, an assemblage of these moving pillars of sand, more numerous, but less in size than the former, approached Mr. Bruce’s party soon after sunrise, and appeared like a thick wood. They almost darkened the sun, the rays of which, shining through them for nearly an hour, gave them an appearance of pillars of fire. His people became desperate, some saying it was the day of judgment, and others, that the world was on fire.
Dr. Clarke, in his travels in Egypt, thus describes this phenomenon. “One of those immense columns of sand, mentioned by Bruce, came rapidly toward us, turning upon its base as upon a pivot: it crossed the Nile so near us, that the whirlwind by which it was carried, placed our vessel upon its beam-ends, bearing its large sail quite into the water, and nearly upsetting the boat. As we were engaged in righting the vessel, the column disappeared. It is probable that those columns do not fall suddenly upon any particular spot, so as to be capable of overwhelming an army or a caravan; but that, as the sand, thus driven, is gradually accumulated, it becomes gradually dispersed, and the column, diminishing in its progress, at length disappears. A great quantity of sand is no doubt precipitated, as the effect which gathers it becomes weaker; but, from witnessing such phenomena upon a smaller scale, it does not seem likely that the whole body of the sand is at once abandoned.”