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Transcribed from the 1846 Society for Promoting Christian Knowledge edition by David Price, email ccx074@pglaf.org
THE RAIN CLOUD:
OR, An Account OF THE NATURE, PROPERTIES, DANGERS, AND USES OF RAIN,
IN VARIOUS PARTS OF THE WORLD.
* * * * *
PUBLISHED UNDER THE DIRECTION OF THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION APPOINTED BY THE SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE.
* * * * *
LONDON: Printed for the SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE. SOLD AT THE DEPOSITORY, GREAT QUEEN STREET, LINCOLN'S INN FIELDS, AND 4, ROYAL EXCHANGE.
1846.
LONDON: R. CLAY, PRINTER, BREAD STREET HILL.
CONTENTS.
CHAPTER I. p. 10. RAINS PECULIAR TO EACH SEASON—SPRING SHOWERS—MIDSUMMER RAINS—RAINS OF AUTUMN AND WINTER—MEANS OF SUPPLYING THE EARTH WITH RAIN—RAIN CLOUDS—DECEPTIVE APPEARANCES OF CLOUDS—THEIR LIGHT AND SHADE—EFFECTS OF CLOUDS IN MOUNTAINOUS COUNTRIES—ASCENT OF MONTE PIENTIO—ASCENT TO THE PEAK OF TENERIFFE—GRAND EFFECTS OF CLOUDS IN THE PYRENEES—VOYAGE IN A BALLOON THROUGH THE CLOUDS. CHAPTER II. p. 37. EFFECTS OF RAIN IN MOUNTAINOUS DISTRICTS—THE DISTRICT OF MORAY—THE GREAT FLOODS OF 1829—COMMENCEMENT OF THE RAIN—THE SWOLLEN RIVERS—DISASTROUS EFFECTS OF THE FLOOD—MEANS ADOPTED FOR THE RESCUE OF COTTAGERS—KERR AND HIS BRAVE DELIVERERS—RESCUE OF FUNNS AND HIS FAMILY—FLOODS OF THE RHONE IN 1840—OVERFLOWING OF THE MISSISSIPPI. CHAPTER III. p. 74. VARIOUS FORMS OF CLOUDS—THE CIRRUS, OR CURL-CLOUD—THE CUMULUS, OR STACKEN-CLOUD—THE STRATUS, OR FALL-CLOUD—THE CIRRO-CUMULUS, OR SONDER-CLOUD—THE CIRRO-STRATUS, OR WANE-CLOUD—THE CUMULO-STRATUS, OR TWAIN-CLOUD—THE NIMBUS, OR RAIN-CLOUD—ARRANGEMENT OF RAIN-CLOUDS—APPEARANCES OF A DISTANT SHOWER—SCUD—CAUSE OF RAIN—FORMATION OF CLOUDS—MISTS—HEIGHTS OF CLOUDS—APPEARANCE OF THE SKY ABOVE THE CLOUDS. CHAPTER IV. p. 107. ON HAIL—THE HAIL-STORMS OF FRANCE—THE DISASTROUS EFFECTS OF HAIL—THE HAIL-STORMS OF SOUTH AMERICA—THEIR SURPRISING EFFECTS—ORIGIN AND NATURE OF HAIL—PERIODICAL FALLS OF HAIL—HAIL CLOUDS—HAILSTONES—THEIR VARIOUS FORMS—EXTRAORDINARY SIZE OF HAILSTONES. CHAPTER V. p. 117. METHOD OF MEASURING THE QUANTITY OF RAIN THAT FALLS—THE RAIN GAUGE—METHODS OF OBSERVING FOR RAIN AND SNOW—EFFECTS OF ELEVATION ON THE QUANTITY OF RAIN—DIFFERENCE BETWEEN THE TOP OF A TALL BUILDING AND THE SUMMIT OF A MOUNTAIN—SIZE OF DROPS OF RAIN—VELOCITY OF THEIR FALL—QUANTITY OF RAIN IN DIFFERENT LATITUDES—EXTRAORDINARY FALLS OF RAIN—REMARKS ON THE RAIN OF THIS COUNTRY—INFLUENCE OF THE MOON—ABSENCE OF RAIN—REMARKABLE DROUGHT IN SOUTH AMERICA—ITS TERRIBLE EFFECTS AND CONSEQUENCES—ARTIFICIAL RAINS. CHAPTER VI. p. 137. THE RAINBOW—DECOMPOSITION OF WHITE LIGHT BY THE PRISM—FORMATION OF PRIMARY AND SECONDARY BOWS—RAINBOWS IN MOUNTAIN REGIONS—THE RAINBOW A SACRED EMBLEM—LUNAR RAINBOW—LIGHT DECOMPOSED BY CLOUDS—THEIR BEAUTIFUL COLOURS—EXAMPLES. CHAPTER VII. p. 157. REMARKABLE SHOWERS—SHOWERS OF SAND—OF MUD—SHOWERS OF SULPHUR, OR YELLOW RAIN—LUMINOUS RAIN—RED RAIN, OR SHOWERS OF BLOOD—SUPERSTITIONS CONNECTED THEREWITH—EXPLANATION OF THE CAUSE—SHOWERS OF FISH—SHOWERS OF RATS—SHOWERS OF FROGS—INSECT SHOWER—SHOWERS OF VEGETABLE SUBSTANCES—MANNA—WHEAT—SHOWERS OF STONES—METEORIC STONES, OR AEROLITES—METEORIC IRON—SUPPOSITIONS RESPECTING THEM—FOSSIL RAIN. CHAPTER VIII. p. 191. COMMON SAYINGS RESPECTING THE WEATHER—SAINT SWITHIN'S-DAY—SIGNS OF RAIN OR OF FAIR WEATHER DERIVED FROM THE APPEARANCE OF THE SUN—FROM THAT OF THE MOON—FROM THE STARS—FROM THE SKY—FROM THE DISTINCTNESS OF SOUNDS—FROM THE RISING OF SMOKE—FROM THE PECULIAR ACTIONS OF PLANTS AND ANIMALS—PROGNOSTICS NOTICED BY SIR HUMPHREY DAVY—SIGNS OF RAIN COLLECTED BY DR. JENNER—NORTH AMERICAN RAIN-MAKERS—INCIDENT RELATED BY CATLIN—RAIN-DOCTORS OF SOUTHERN AFRICA—RAIN-DOCTORS OF CEYLON—SUPERSTITIONS GIVING WAY TO THE TEACHING OF MISSIONARIES—CONCLUSION.
[Picture: Clouds among the mountains]
CHAPTER I:
RAINS PECULIAR TO EACH SEASON—SPRING SHOWERS—MIDSUMMER RAINS—RAINS OF AUTUMN AND WINTER—MEANS OF SUPPLYING THE EARTH WITH RAIN—RAIN-CLOUDS—DECEPTIVE APPEARANCES OF CLOUDS—THEIR LIGHT AND SHADE—EFFECTS OF CLOUDS IN MOUNTAINOUS COUNTRIES—ASCENT OF MONTE PIENTIO—ASCENT TO THE PEAK OF TENERIFFE—GRAND EFFECTS OF CLOUDS IN THE PYRENEES—VOYAGE IN A BALLOON THROUGH THE CLOUDS.
Every season has its own peculiar rains. What can be more refreshing or invigorating than the showers of spring? When the snows of February have disappeared, and the blustering winds of March have performed their office of drying up the excess of moisture, and preparing the earth for fruitfulness, and when the young buds and blossoms of April are peeping forth beneath the influence of the sun, and the trees and hedges are attired in their new robes of tender green, how soon would all this beauty languish but for the showers of spring! Several dry days, perhaps, have passed, and the wreaths of dust which are raised by the wind show that the earth wants moisture; but before a drop falls there is a general lull throughout all nature; not a leaf is heard to rustle; the birds are mute and the cattle stand in expectation of the refreshing fall. At last the pools and rivulets are "dimpled" by a few soft drops, the forerunners of the general shower. And this shower, unlike the heavier rains of summer, comes stealing on so gently, that the tinkling sound of its fall is heard among the branches of the bursting trees long before it is felt by those who walk beneath their slight shelter. Rapidly does the landscape brighten under the influence of the welcome shower; and as it becomes more rich and extensive, all nature seems to rise up and rejoice. The birds chirp merrily among the foliage; the flowers raise their drooping heads, and the thirsty ground drinks in with eager haste the mellowing rains. All day long, perhaps, does the rain continue to fall, until the earth is fully moistened and "enriched with vegetable life." At length, towards evening, the sun peeps out from among the broken clouds, and lights up, by his sudden radiance, the lovely scene. Myriads of rain-drops sparkle like gems beneath his beams; a soft mist that seems to mingle earth and sky gradually rolls away, and "moist, and bright, and green, the landscape laughs around." Now pours forth the evening concert from the woods, while warbling brooks, and lowing herds, appear to answer to the sound. Such are some of the delightful effects of spring-showers.
In summer, when the heat has been very great, the rain is often ushered in by a thunder-storm, and falls in torrents, which at an earlier season would do harm to the young buds and blossoms of spring; but now the vegetation is strong enough to resist the floods so necessary to maintain moisture in the parched earth. But when the summer has been moderately warm some gentle rains generally fall about midsummer, which, from the frequency of their occurrence about this time, have obtained the name of "Midsummer rains." These rains are popularly associated with St. Swithin's Day, as will be noticed in another chapter; but when they fall early, mildly, and in moderate quantity, they operate to a certain extent as a second spring. "Many of the birds come into song and have second broods; and it is probable that there is a fresh production of caterpillars for their food, or, at all events, a larger production of the late ones than when the rains are more violent and protracted. Many of the herbaceous plants also bloom anew, and the autumn is long and pleasant, and has very many of the charms of a summer, though without any very powerful operation on the productions of nature, further than a very excellent preparation for the coming year, whether in buds, in roots, or in the labours of man. Such a season is also one of plenty, or at all events of excellent quality in all the productions of the soil. The wild animals partake in the general abundance, as that food which is left for them in the fields, after man has gathered in his share, is both more abundant and more nourishing. When there is much moisture from the protracted time and great quantity of the rains, many of those seeds germinate, while in mild seasons they are left as food for the wild animals, chiefly the field-mice and the birds, which again form part of the food of the predatory ones."
There is something melancholy and depressing in the rains of autumn and winter, for they bear away the last traces of summer by stripping the trees of the many-coloured leaves, which in mild seasons will continue to adorn the landscape even late in November. The rains of this month, and their effects, have been skilfully sketched by an accurate observer of nature. He says:—
"Now cold rains come deluging down, till the drenched ground, the dripping trees, the pouring eaves, and the torn, ragged-skirted clouds, seemingly dragged downward slantwise by the threads of dusky rain that descend from them, are all mingled together in one blind confusion; while the few cattle that are left in open pastures, forgetful of their till now interminable business of feeding, turn their backs upon the besieging storm, and, hanging down their heads till their noses almost touch the ground, stand out in the middle of the fields motionless, like dead images.
"Now, too, a single rain-storm, like the above, breaks up all the paths and ways at once, and makes home no longer 'home' to those who are not obliged to leave it; while it becomes doubly endeared to those who are. What sight, for instance, is so pleasant to the wearied woodman, who has been out all day long in the drenching rains of this month, as his own distant cottage window seen through the thickening dusk, lighted up by the blazing fagot that is to greet his sure return at the accustomed minute?"
While we watch the effects of the various rains, and their beneficial influence on the earth, there is also much to excite our gratitude and admiration; for among the many beautiful contrivances in creation, none is more remarkable than the means by which the earth is watered and refreshed by rain. The oceans, seas, lakes, and other waters of the earth supply the air with moisture, which, rendered elastic and invisible by the heat of the sun and of the earth, rises to various heights in the atmosphere, where it forms clouds in all their wonderful beauty and variety. These are borne by the winds to places far inland, to which water in sufficient quantity could not come by any other means, and where moisture is most required; and here the water is poured down, not in cataracts and water-spouts, but in the form of drops of various sizes. If the rain-clouds threw down, at once and suddenly, all the water contained in them, not only would vegetation be destroyed by the force of the fall, but we should be constantly liable to floods and other inconveniences. Clouds also serve to screen the earth from the fierce heat of the sun by day; and, by night, they serve to maintain the heat which would otherwise escape by radiation, and produce great cold even in summer. Clouds thus have great influence in regulating the extremes of heat and cold, and in forming what is called the "climate" of a country. Clouds also supply the hidden stores of fountains and the fresh water of rivers; and, as a pious old divine well remarks, "So abundant is this great blessing, which the most indulgent Creator hath afforded us by means of this distribution of the waters I am speaking of, that there is more than a scanty, bare provision, a mere sufficiency; even a plenty, a surplusage of this useful creature of God, the fresh waters afforded to the world; and they so well ordered, as not to drown the nations of the earth, nor to stagnate, stink, and poison, or annoy them; but to be gently carried through convenient channels back again to their grand fountain the sea; and many of them through such large tracts of land and to such prodigious distances, that it is a great wonder the fountains should be high enough, or the seas low enough, ever to afford so long a conveyance." {18}
If rain is not at all seasons pleasant and delightful, neither are rain-clouds among the most beautiful which diversify the landscape of the sky; for it has been well remarked, that "all the fine-weather clouds are beautiful, and those connected with rain and wind mostly the reverse." What, indeed, can be more striking than the aerial landscapes of fine weather, in which, by an easy fancy, we can trace trees and towers, magnificent ruins and glaciers, natural bridges and palaces, all dashed with torrents of light or frowning in shadow, glowing like burnished silver, glittering in a golden light, or melting into the most enchanting hues? But with all this beauty the eye is seldom capable of judging correctly of the proper size and forms and motions of clouds. The same cloud which to one observer may be glowing with light, to another may be enveloped in shadow. That which appears to be its summit may be only a portion of its outer edge, while that which seems to be its lower bed may really be a portion of its further border. A spectator, on the summit of a tall cliff, may observe what he takes to be a single cloud; while a second spectator, on lower ground, will perceive that there are two clouds. The motions of clouds are so deceptive, that they often seem to be moving in a curve over the great concave of heaven, while they are in fact advancing in nearly a right line. Suppose, for example that a cloud is moving from the distant horizon towards the place where we stand, in a uniform horizontal line without changing either in size or form. Such a cloud, when first seen, will appear to be in contact with the distant horizon, and consequently much nearer to us than it really is. As it advances towards us, it will seem to rise into the sky, and to become gradually larger till it is almost directly overhead. Continuing its progress, it will then seem again to descend and to lessen in size as gradually as it had before increased; till at length it disappears in the distant horizon at a point exactly opposite to that at which it was first seen. Thus the same cloud, without varying its motion in the least from a straight line, and remaining throughout of the same size and form, would seem to be continually varying in magnitude; and the line of its motion, instead of being straight, would appear to be curved. This is one of the most simple cases that can be supposed: but the clouds as they exist in nature do not remain of the same magnitude, but are constantly changing in form, in size, in direction, and in velocity; so that it is quite impossible to form an accurate idea of their shape and size, or to explain their motions. Clouds, at different elevations, may often be seen to move in different directions under the influence of different currents of wind.
[Picture: Different appearance of the same clouds to different observers]
The distribution of light and shade in clouds is most striking. The watery particles of which they are composed, yielding constantly to changes in temperature and moisture, are always changing; so that a most beautiful cloud may alter in figure and appearance in an instant of time; the light parts may suddenly become dark, and those that were shaded may all at once glow in the rays of the sun. Again, the appearance of a cloud, with respect to the sun, may entirely alter its character. The same cloud, to one observer, may appear entirely in shade, to another tipped with silver; to a third it may present brilliant points and various degrees of shade, or one of its edges only may appear illuminated; sometimes the middle parts may appear in shadow, while the margin may be partially luminous, rendering the middle parts all the more obscure by the contrast.
A wonderful variety may also be produced by the shadow of one cloud falling upon another. The accompanying sketch furnishes an example of this. Sometimes the whole of a cloud projects a shadow through the air upon some other far distant cloud, and this again upon another, until at length it reaches the ground. The shadows of moving clouds may often be traced upon the ground, and they contribute greatly to modify the appearance of the landscape. A large number of small flickering clouds produce broken lights and shades which have an unpleasant jarring effect; but when the clouds are massive, or properly distributed, the shadows often produce a high degree of repose.
[Picture: Shadows of clouds]
Clouds are often seen to advantage in mountainous countries. Here the aspect of the heavens may be entirely different at different elevations. A single cloud in the valley may conceal the whole of the upper sky from an observer; but as he ascends he may gradually get above this and other layers or bands of cloud, and see a beautifully variegated sky above him, while the clouds which conceal the valley may be rolling at his feet. Evelyn, in his Memoirs, notices a scene of this kind. He says,—"Next morning we rode by Monte Pientio, or, as vulgarly called, Monte Mantumiato, which is of an excessive height, ever and anon peeping above airy clouds with its snowy head, till we had climbed to the inn at Radicofany, built by Ferdinand the greate Duke for the necessary refreshment of travellers in so inhospitable a place. As we ascended we entered a very thick, solid, and dark body of cloudes, which looked like rocks at a little distance, which lasted neare a mile in going up; they were dry, misty vapours, hanging undissolved for a vast thicknesse, and obscuring both sun and earth, so that we seemed to be in the sea rather than in the cloudes, till, having pierced through it, we came into a most serene heaven, as if we had been above all human conversation, the mountain appearing more like a great island than joyn'd to any other hills, for we could perceive nothing but a sea of very thick cloudes rowling under our feete like huge waves, every now and then suffering the top of some other mountain to peepe through, which we could discover many miles off: and betweene some breaches of the cloudes we could see landskips and villages of the subjacent country. This was one of the most pleasant, newe, and altogether surprising objects that I had ever beheld."
In the following interesting account of the ascent of the Peak of Teneriffe by Captain Basil Hall, it will be seen that heavy rain clouds may skirt the mountain, while its summit is in a pure and dry air.
"On the 24th of August," he says, "we left Oratava to ascend the Peak. The day was the worst possible for our purpose, as it rained hard; and was so very foggy that we could not see the Peak, or indeed any object beyond one hundred yards distant.
"After riding slowly up a rugged path for four hours, it became extremely cold, and, as the rain never ceased for an instant, we were by this time drenched to the skin, and looked with no very agreeable feelings to the prospect of passing the night in wet clothes. At length the night began to close in, and the guides talked of the improbability of reaching the English station before night. It was still raining hard; but we dismounted, and took our dinner as cheerfully as possible, and hoping for clearer weather the next day. On remounting, we soon discovered that the road was no longer so steep as it had been heretofore, and the surface was comparatively smooth: we discovered, in short, that we had reached a sort of table-land, along which we rode with ease. Presently we thought the fog less dense, and the drops of rain not so large, and the air less chilling. In about half an hour we got an occasional glimpse of the blue sky; and as we ascended, (for our road, though comparatively level, was still upon the rise,) these symptoms became more manifest. The moon was at the full, and her light now became distinct, and we could see the stars in the zenith. By this time we had reached the Llano de los Remenos, or Retamos Plain, which is many thousand feet above the sea; and we could distinctly see that during the day we had merely been in a cloud, above which having now ascended, the upper surface lay beneath us like a country covered with snow. It was evident, on looking round, that no rain had fallen on the pumice gravel over which we were travelling. The mules were much fatigued, and we got off to walk. In a few minutes our stockings and shoes were completely dried, and in less than half an hour all our clothes were thoroughly dried. The air was sharp and clear, like that of a cold frosty morning in England; and though the extreme dryness, and the consequent rapid evaporation, caused considerable cold, we were enabled by quick exercise to keep ourselves comfortable. I had various instruments with me, but no regular hygrometer: accident, however, furnished me with one sufficiently indicative of the dry state of the air. My gloves, which I kept on while mounted, were completely soaked with the rain; and I took them off during this walk, and, without considering what was likely to happen, rolled them up, and carried them in my hand. When, at the end of an hour, or somewhat less, we came to remount our mules, I found the gloves as thoroughly dried and shrivelled up as if they had been placed in an oven. During all the time we were at the Peak itself, on the 26th, the sky was clear, the air quite dry, and we could distinguish, several thousand feet below us, the upper and level surface of the stratum of clouds through which we had passed the day before, and into which we again entered on going down, and found precisely in the same state as when we started."
It is not uncommon to observe an effect quite contrary to the one given in the last two examples, the high summits of mountains being frequently concealed by heavy clouds of mist, while at a very short distance below them the air is clear and pure. In ascending to the Port of Venasque, one of the mountain passes of the Pyrenees, Mr. Murray found the mists so dense that he despaired of getting above them, or of their clearing away. But fortunately the wind freshened, and the mist, broken by it, "came sweeping," he says, "over our heads, sometimes enveloping us in darkness, sometimes exposing the blue sky, and a part of the mountains. Section after section of the bald and towering masses which rose above the path were displayed to us, one after another, as if the whole had been a sight too great for us to look upon. Sometimes the clouds opened, and the snows, sparkling in the sun-beams, were before us; at others, an enormous peak of the mountain would shoot its dark head through the mist, and, without visible support, seem as if it were about to fall upon us. Again, when we imagined ourselves hemmed in on all sides by the mountains, and within a few feet of their rugged sides, a passing breeze would disclose the dark waters of the lakes hundreds of feet beneath us.
"Thus the effect of light and darkness, of sunshine and of mist, working upon materials of such grandeur as those near the Port of Venasque, was a sight well worthy of admiration, and one which is rarely to be seen. * * * * Excepting the intervals of light which the gusts of wind, by dispersing the mists, had bestowed upon us, we had hitherto, comparatively speaking, been shrouded in darkness, particularly for the ten minutes preceding our arrival at the Port: my astonishment may therefore be imagined when, the instant that I stepped beyond the limits of the Port, I stood in the purest atmosphere—not a particle of mist, not even a cloud, was perceptible. The phenomenon was curious, and its interest greatly heightened from the situation in which it took place. The mist rolling up the valley through which we had passed, was, the moment that it could be said to reach the Spanish frontier,—the moment it encircled the edges of the high ridges which separated the countries, thrown back, as it were, indignantly, by a counter current from the Spanish side. The conflicting currents of air, seemingly of equal strength, and unable to overcome each other, carried the mist perpendicularly from the summits of the ridge, and filling up the crevices and fissures in its uneven surface, formed a wall many thousand feet above it, of dark and (from the appearance of solidity which its massive and perpendicular character bestowed upon it) apparently impenetrable matter."
Undoubtedly the various phenomena of clouds may be seen to great advantage in mountain regions; and there is only one other method of seeing them to greater perfection, and that is from the car of a balloon. The following description of an aerial voyage, by Mr. M. Mason, in October 1836, will convey a better idea of the magnificence of a cloudy sky than any terrestrial prospect could do. He says,—
"Scarcely had we quitted the earth before the clouds, which had previously overhung us, began to envelop us on all sides, and gradually to exclude the fading prospect from our sight. It is scarcely possible to convey an adequate idea of the effect produced by this apparently trivial occurrence. Unconscious of our own motion from any direct impression upon our own feelings, the whole world appeared to be in the act of receding from us in the dim vista of infinite space; while the vapoury curtain seemed to congregate on all sides and cover the retreating masses from our view. The trees and buildings, the spectators and their crowded equipages, and finally, the earth itself, at first distinctly seen, gradually became obscured by the thickening mist, and growing whiter in their forms, and fainter in their outlines, soon faded away 'like the baseless fabric of a vision,' leaving us, to all appearance, stationary in the cloud that still continued to involve us in its watery folds. To heighten the interest and maintain the illusion of the scene, the shouts and voices of the multitude whom we had left behind us, cheering the ascent, continued to assail us, (long after the interposing clouds had effectually concealed them from our eyes,) in accents which every moment became fainter and fainter till they were finally lost in the increasing distance.
"Through this dense body of vapour, which may be said to have commenced at an altitude of about 1000 feet, we were borne upwards to perhaps an equal distance, when the increasing light warned us of our approach to its superior limits, and shortly after, the sun and we rising together, a scene of splendour and magnificence suddenly burst upon our view, which it would be vain to expect to render intelligible by any mode of description within our power. Pursuing the illusion, which the previous events had been so strongly calculated to create, the impression upon our senses was that of entering upon a new world to which we had hitherto been strangers, and in which not a vestige could be perceived to remind us of that we had left, except the last faint echo of the voices which still dimly reached us, as if out of some interminable abyss into which they were fast retreating.
"Above us not a single cloud appeared to disfigure the clear blue sky, in which the sun on one side, and the moon in her first quarter on the other, reigned in undisturbed tranquillity. Beneath us, in every direction, as far as the eye could trace, and doubtless much further, the whole plane of vision was one extended ocean of foam, broken into a thousand fantastic forms; here swelling into mountains, there sinking into lengthened fosses, or exhibiting the appearance of vast whirlpools; with such a perfect mimicry of the real forms of nature, that, were it not for a previous acquaintance with the general character of the country below us, we should frequently have been tempted to assert, without hesitation, the existence of mountainous islands penetrating through the clouds, and stretching in protracted ranges along the distant verge of our horizon.
"In the centre of this hemisphere, and at an elevation of about 3000 feet above the surface of the clouds, we continued to float in solitary magnificence; attended only at first by our counterpart—a vast image of the balloon itself with all its paraphernalia distinctly thrown by the sun upon the opposite masses of vapour, until we had risen so high that even that, outreaching the material basis of its support, at length deserted us; nor did we again perceive it until, preparatory to our final descent, we had sunk to a proper elevation to admit of its re-appearance.
"Not the least striking feature of our, and similar situations, is the total absence of all perceptible motion, as well as of the sound which, in ordinary cases, is ever found to accompany it. Silence and tranquillity appear to hold equal and undisputed sway throughout these airy regions. No matter what may be the convulsions to which the atmosphere is subjected, nor how violent its effects in sound and motion upon the agitated surface of the earth, not the slightest sensation of either can be detected by the individual who is floating in its currents. The most violent storm, the most outrageous hurricane, pass equally unheeded and unfelt; and it is only by observing the retreating forms of the stable world beneath, that any certain indication can be obtained as to the amount or violence of the motion to which the individual is actually subjected. This, however; was a resource of which we were unable to avail ourselves, totally excluded as we were from all view of the earth, or any fixed point connected with it.
"Once, and only once, for a few moments preparatory to our final descent, did we obtain a transitory glimpse of the world beneath us. Upon approaching the upper surface of the vapoury strata, which we have described as extending in every direction around, a partial opening in the clouds discovered to us for an instant a portion of the earth, appearing as if dimly seen through a vast pictorial tube, rapidly receding behind us, variegated with furrows, and intersected with roads running in all directions; the whole reduced to a scale of almost graphic minuteness, and from the fleecy vapour that still partially obscured it, impressing the beholder with the idea of a vision of enchantment, which some kindly genius had, for an instant, consented to disclose. Scarcely had we time to snatch a hasty glance, ere we had passed over the spot, and the clouds uniting gradually concealed it from our view.
"After continuing for a short space further, in the vain hope of being again favoured with a similar prospect, the approach of night made it desirable that we should prepare for our return to earth, which we proceeded to accomplish accordingly."
[Picture: Kerr and his family in the middle of the flood]
CHAPTER II.
EFFECTS OF RAIN IN MOUNTAINOUS DISTRICTS—THE DISTRICT OF MORAY—THE GREAT FLOODS OF 1829—COMMENCEMENT OF THE RAIN—THE SWOLLEN RIVERS—DISASTROUS EFFECTS OF THE FLOOD—MEANS ADOPTED FOR THE RESCUE OF COTTAGERS—KERR AND HIS BRAVE DELIVERERS—RESCUE OF FUNNS AND HIS FAMILY—FLOODS OF THE RHONE IN 1840—OVERFLOWING OF THE MISSISSIPPI.
It is well known that some years are wetter than others; but to persons living in tolerably flat countries an unusually wet season causes no great inconvenience. It interferes, it is true, with outdoor employments, but people seldom apprehend any danger from the long continuance of rain. It is not so, however, in hilly or mountainous regions; an unusual fall of rain swells the rivers to such an extent, that they often overflow their banks, and occasion much damage to the surrounding districts; or, where the river's banks are defended on both sides by perpendicular rocks, the waters sometimes rise so fast as to attain a height of forty or fifty feet above their natural level, and from this height they pour with destructive violence over the face of the country. Such was the case in the great floods of Moray, which happened in the year 1829, of which the following is a brief abstract, derived chiefly from Sir Thomas Dick Lauder's interesting volume on this subject, published soon after the calamity for the benefit of the sufferers.
The province of Moray, or Murray, is a large district in the north-east of Scotland, bounded by the Moray Frith on the north-east and north. The eastern half of the province is lower than the western; in which the mountains render the whole country characteristically highland. On the north is a long belt of lowlands, about 240 square miles in extent: this is greatly diversified with ridgy swells and low hilly ranges, lying parallel to the frith, and intersected by the rivers Ness, Nairn, Findhorn, Lossie, and Spey running across it to the sea. The grounds behind the lowlands appear, as seen from the coast, to be only a narrow ridge of bold alpine heights, rising like a rampart to guard the orchards, and woods, and fields: but these really form long and broad mountain masses, receding, in all the wildness and intricacy of highland arrangement, to a distant summit line. Some of the broad clifts and long narrow vales of these mountains form beautiful and romantic pictures; while many of their declivities are practicable to the plough or other instruments of cultivation; so that the bottoms and the reclaimed or reclaimable sides of the valleys are estimated to comprehend about one-third of the entire area. The lowlands of Moray have long been celebrated for mildness and luxuriousness of climate, and also for a certain dryness of atmosphere, which seems to have some intimate connexion with the mournful calamity about to be described. The high broad range of mountains on the south-west shelter the lowlands from the prevailing winds of the country, and exhaust many light vapours and thinly-charged clouds, which might otherwise produce gentle rains; but, for just the same reason, they powerfully attract whatever long broad streams of heavy clouds are sailing through the sky, and, among the gullies and the upland glens, amass their discharged contents with amazing rapidity, and in singular largeness of volume. The rivers of the country are, in consequence, peculiarly liable to become flooded. One general and tremendous outbreak, in 1829, "afforded an awful exhibition of the peculiarities of the climate, and will long be remembered, in connexion with the boasted luxuriousness of Moray, as an illustration of how chastisement and comfort are blended in a state of things which is benignly adjusted for the moral discipline of man, and the correction of moral evil."
The heat in the province of Moray during the summer of 1829 was unusually great. In May the drought was so excessive, as to kill many of the recently planted shrubs and trees. As the season advanced, the variations in the barometer became so remarkable, that observers began to lose all confidence in this instrument.
The deluge of rain, which produced the flood of the 3d and 4th of August, fell chiefly on the Monadhlradh mountains, rising between the south-east part of Lochness and Kingussie, in Badenoch, and on that part of the Grampian range forming the somewhat independent groups of the Cairngorums. The westerly winds, which prevailed for some time previously, seem to have produced a gradual accumulation of vapour to the north of our island, and the column, being suddenly impelled by a strong north-easterly blast, was driven towards the south-west, its right flank almost sweeping the Caithness and Sutherland coasts, until rushing up and across the Moray Frith it was attracted by the lofty mountains just mentioned, and discharged in fearful torrents. There fell at a great distance from the mountains, within twenty-four hours, about one-sixth of the annual allowance of rain; on the mountains themselves the deluge that descended, must have been so enormous as to occasion surprise that a flood, even yet more tremendous in its magnitude and consequences, did not result from it.
The mouth of the Findhorn is described as the most important scene of action. The banks of this river are well defended by rocks on either side, and its whole course is distinguished by the most romantic scenery. At the part where it is crossed by the old military bridge of Dulsie, the scenery is of the wildest character. The flood was most tremendous at this bridge, for the water was so confined that it filled the smaller arch altogether, and rose in the great arch to within three feet of the key-stone, that is to say, forty feet above the usual level. This fine old bridge sustained but little damage, while many of the modern buildings were entirely swept away. At another part of the river, it is stated, as a curious illustration of the height to which the stream had risen, that a gardener waded into the water as it had begun to ebb on the haugh, and with his umbrella drove ashore and captured a fine salmon, at an elevation of fifty feet above the ordinary level of the Findhorn.
At Randolph's bridge the opening expands as the rocks rise upwards, till the width is about seventy or eighty feet; yet, from the sudden turn of the river, as it enters this passage, the stream was so checked in its progress that the flood actually rose over the very top of the rocks, forty-six feet above the usual height, and inundated the level part that lies over them to the depth of four feet, making a total perpendicular rise at this point of not less than fifty feet.
The effects of the deluge of the 3d and 4th of August, remain on the Dorbach, in a bank one hundred feet high, which rose with slopes and terraces covered with birch and alder wood. The soil being naturally spongy imbibed so much rain, that it became overloaded, and a mass of about an acre in extent, with all its trees on it, gave way at once, threw itself headlong down, and bounded across the bed of the Dorbach, blocking up the waters, flooded and wide as they were at the time. A farmer, who witnessed this phenomenon, told Sir Thomas Dick Lauder that it fell "wi' a sort o' a dumb sound," while astonished and confounded he remained gazing at it. The bottom of the valley is here some two hundred yards or more wide, and the flood nearly filled it. The stoppage was not so great, therefore, as altogether to arrest the progress of the stream; but this sudden obstacle created an accumulation of water behind it, which went on increasing for nearly an hour, till, becoming too powerful to be longer resisted, the enormous dam began to yield, and was swept off at once, and hurled onwards like a floating island. While the farmer stood lost in wonder to behold his farm thus sailing off to the ocean by acres at a time, another half acre, or more, was suddenly rent from its native hill, and descended at once, with a whole grove of trees on it, to the river, where it rested on its natural base. The flood immediately assailed this, and carried off the greater part of it piecemeal. At the time when Sir Thomas was writing, part of it remained with the trees growing on it in the upright position, after having travelled through a horizontal distance of sixty or seventy yards, with a perpendicular descent of not less than sixty feet.
[Picture: The flood like—Brig of Bannock. (The dotted line shows the height gained by the flood above the usual level of the stream)]
At Dunphail, the residence of Mr. Bruce was threatened by the flood, and that gentleman prevailed on his wife and daughter to quit the house and seek refuge on higher ground. Before quitting the place, their anxiety had been extremely excited for the fate of a favourite old pony, then at pasture in a broad green, and partially-wooded island, of some acres in extent. As the spot had never been flooded in the memory of man, no one thought of removing the pony until the wooden bridges having been washed away rendered it impossible to do so. When the embankment gave way, and the patches of green gradually diminished, Dobbin, now in his 27th year, and in shape something like a 74-gun ship cut down to a frigate, was seen galloping about in great alarm as the wreck of roots and trees floated past him, and as the last spot of grass disappeared he was given up for lost. At this moment he made a desperate effort to cross the stream under the house; the force of the current turned him head over heels, but he rose again with his head up the river; he made boldly up against it, but was again borne down and turned over: every one believed him lost, when rising once more and setting down the waste of water, he crossed both torrents, and landed safely on the opposite bank.
At night Mr. Bruce says there was something inexpressibly fearful and sublime in the roar of the torrent, which by this time filled the valley, the ceaseless plash of the rain, and the frequent and fitful gusts of the north wind that groaned among the woods. The river had now undermined the bank the house stood on, and this bank had already been carried away to within four paces of the foundation of the kitchen tower, and, as mass after mass fell with a thundering noise, some fine trees, which had stood for more than a century on the terrace above it, disappeared in the stream. The operations of the flood were only dimly discovered by throwing the faint light of lanterns over its waters, and its progress was judged of by marking certain intervals of what remained of the terrace. One by one these fell in, and at about eleven o'clock the river was still rising, and only a space of three yards remained about the house, which was now considered as lost. The furniture was ordered to be removed, and by means of carts and lanterns this was done without any loss. About one o'clock in the morning, the partial subsidence of the flood awakened a slight hope, but in an hour it rose again higher than before. The banks which supported the house were washed away, and the house itself seemed to be doomed, and the people were therefore sent out of it. But Providence ordered otherwise; about four o'clock the clouds appeared higher, the river began again to subside; by degrees a little sloping beach became visible towards the foot of the precipice; the flood ceased to undermine, and the house was saved.
But the ruin and devastation of the place were frightful to behold. The shrubbery, all along the river side, with its little hill and moss-house, had vanished; two stone and three wooden buildings were carried off; the beautiful fringe of wood on both sides of the river, with the ground it grew on, were washed to the ocean, together with all those sweet and pastoral projections of the fields which gave so peaceful and fertile a character to the valley; whilst the once green island, robbed of its groups of trees and furrowed by a dozen channels, was covered with large stones, gravel, and torn-up roots.
At another part of the same river (the Divie) Sir Thomas describes, from his own observations, the progress of the flood. The noise was a distinct combination of two kinds of sound: one, an uniform continued roar; the other, like rapidly repeated discharges of cannon. The first of these proceeded from the violence of the water; the other, which was heard through it, and as it were muffled by it, came from the numerous stones which the stream was hurling over its uneven bed of rock. Above all this was heard the shrieking of the wind. The leaves were stripped off the trees and whirled into the air, and their thick boughs and stems were bending and cracking beneath the tempest. The rain was descending in sheets, not in drops: and a peculiar lurid, bronze-like hue pervaded the whole face of nature. And now the magnificent trees were overthrown faster and faster, offering no more resistance than reeds before the mower's scythe. Numerous as they were, they were all, individually, well-known friends. Each, as it fell, gave one enormous plash on the surface, then a plunge, the root upwards above water for a moment; again all was submerged—and then up rose the stem disbranched and peeled; after which, they either toiled round in the cauldron, or darted, like arrows, down the stream. "A chill ran through our hearts as we beheld how rapidly the ruin of our favourite and long-cherished spot was going on. But we remembered that the calamity came from the hand of God; and seeing that no human power could avail, we prepared ourselves to watch every circumstance of the spectacle." In the morning the place was seen cleared completely of shrubs, trees, and soil; and the space so lately filled with a wilderness of verdure was now one vast and powerful red-coloured river.
On the left bank of the Findhorn the discharge of water, wreck, and stones that burst over the extensive plain of Forres, spreading devastation abroad on a rich and beautiful country, was truly terrific. On the 3d of August, Dr. Brands, of Forres, having occasion to go to the western side of the river, forded it on horseback, but ere he crossed the second branch of the stream, he saw the flood coming thundering down. His horse was caught by it; he was compelled to swim; and he had not long touched dry land ere the river had risen six feet. By the time he had reached Moy the river had branched out into numerous streams, and soon came rolling on in awful grandeur; the effect being greatly heightened by the contrary direction of the northerly wind, then blowing a gale. Many of the cottages occupied a low level, and the inhabitants were urged to quit them. Most of them did so; but some, trusting to their apparent distance from the river, refused to move.
About ten o'clock the river had risen and washed away several of the cottages; and on every side were heard reports of suffering cottagers, whose houses were surrounded by water. One of them was Sandy Smith, an active boatman, commonly called Whins, (or Funns, as it is pronounced,) from his residence on a piece of furzy pasture, at no great distance from the river. From the situation of his dwelling he was given up for lost; but for a long time the far-distant gleam of light that issued from his window showed that he yet lived.
The barns on the higher grounds accommodated many people; and large quantities of brose (broth) were made for the dripping and shivering wretches. Candles were placed in all the windows of the principal house (that of Mr. Suter) that poor Funns might see he was not forgotten. But, alas! his light no longer burns, and in the midst of the tempest and darkness, it was utterly vain to attempt to assist the distressed.
At daybreak the wide waste of waters was only bounded by the rising grounds on the south and west: whilst, towards the north and east, the watery world swept off, uninterruptedly, into the expanding Frith and the German Ocean. The embankments appeared to have everywhere given way; and the water that covered the fields, lately so beautiful with yellow wheat, green turnips, and other crops, rushed with so great impetuosity in certain directions, as to form numerous currents, setting furiously through the quieter parts of the inundation, and elevated several feet above it. As far as the eye could reach the brownish-yellow moving mass of water was covered with trees and wreck of every description, whirled along with a force that shivered many of them against unseen obstacles. There was a sublimity in the mighty power and deafening roar of waters, heightened by the livid hue of the clouds, the sheeting rain, the howling of the wind, the lowing of the cattle, and the screaming and wailing of the assembled people, that riveted the attention. In the distance could dimly be descried the far-off dwelling of poor Funns, its roof rising like a speck above the flood, that had evidently made a breach in one of its ends.
A family named Kerr, who had refused to quit their dwelling, were the objects of great anxiety. Their son, Alexander Kerr, had been watching all night, and in the morning was still gazing towards the spot in an agony of mind, and weeping for the apparently inevitable destruction of his parents. His master tried to comfort him; but even whilst he spoke, the whole gable of Kerr's dwelling, which was the uppermost of three houses composing the row, gave way, and fell into the raging current. Dr. Brands, who was looking on intently at the time, with a telescope, observed a hand thrust through the thatch of the central house. It worked busily, as if in despair of life; a head soon appeared; and at last Kerr's whole frame emerged on the roof, and he began to exert himself in drawing out his wife and niece. Clinging to one another, they crawled along the roof towards the northern chimney. The sight was torturing. Kerr, a little a-head of the others, was seen tearing off the thatch, as if trying to force an entrance through the roof, whilst the miserable women clung to the house-top, the blankets which they had used to shelter them almost torn from them by the violence of the hurricane; and the roof they had left yielding and tottering, fell into the sweeping flood. The thatch resisted all Kerr's efforts; and he was now seen to let himself drop from the eaves on a small speck of ground higher than the rest, close to the foundation of the back wall of the buildings, which was next the spectators. There he finally succeeded in bringing down the women; and there he and they stood, without even room to move.
[Picture: Perilous situation of Kerr and his family]
Some people went on horseback to try to procure boats. They managed to get on some way by keeping the line of road. The water was so deep that the horses were frequently swimming; but at length the current became so strong that they were compelled to seek the rising grounds. Dr. Brands attempted to reach the bridge of Findhorn, in hopes of getting one of the fishermen's cobbles. As he was approaching the bridge he learned that the last of the three arches had fallen the instant before; and when he got to the brink, the waters were sweeping on as if it had never been, making the rocks and houses vibrate with a distinct and tremulous motion. The current was playing principally against the southern approach of the bridge, and soon the usually dry arch, at its further end, burst with a loud report; its fragments, mixed with water, being blown into the air as if by gunpowder. The boats had all been swept away, and the fishermen's houses were already one mass of ruin. The centre of the main stream was hurried on at an elevation many feet higher than the rest of the surrounding sea of waters; the mighty rush of which displayed its power in the ruin it occasioned. Magnificent trees, with all their branches, were dashing and rending against the rock, and the roaring and crashing sound that prevailed was absolutely deafening.
As there was no chance of getting a boat the Doctor returned with difficulty to the house, his mare swimming a great part of the way. On again looking through the telescope at poor Kerr and his family, they were seen huddled together on a spot of ground a few feet square, some forty or fifty yards below their inundated dwelling. {55} He was sometimes standing and sometimes sitting on a small cask, and, as the beholders fancied, watching with intense anxiety the progress of the flood, and trembling for every large tree that it brought sweeping past them. His wife, covered with a blanket, sat shivering on a bit of a log, one child in her lap, and a girl of about seventeen, and a boy of about twelve years of age, leaning against her side. A bottle and a glass on the ground near the man gave the spectators, as it had doubtless given him, some degree of comfort. Above a score of sheep were standing around, or wading, or swimming in the shallows. Three cows and a small horse picking at a broken rick of straw that seemed to be half afloat, were also grouped with the family. Dreading that they must all be swept off, if not soon relieved, the gentlemen hastened to the offices, and looked anxiously out from the top of the tower for a boat. At last they had the satisfaction to see one launched from the garden at Earnhill, about a mile below. The boat had been conveyed by a pair of horses, and had only just arrived. It was nobly manned by three volunteers, and they proceeded at once to the rescue of a family who were in a most perilous situation in the island opposite to Earnhill. The gentlemen on the tower watched the motions of this boat with the liveliest interest. They saw it tugging up till it was hid from them by the wood. Again it was seen beyond, and soon it dashed into the main stream and disappeared again behind the wood, with a velocity so fearful that they concluded it was lost. But in a moment it again showed itself, and the brave fellows were seen plying their oars across the submerged island of Earnhill, making for John Smith's cottage; the thatch and a small part of the side walls of which were visible above the water. The poor inmates were dragged out of the windows from under the water, having been obliged to duck within ere they could effect their escape. The boat then swept down the stream towards a place called 'The Lakes,' where John Smith, his wife, and her mother were safely landed.
The boat was next conveyed by the horses to a point from which it was launched for the rescue of the Kerrs. Having pulled up as far as they could in the still water, they approached the desperate current, and fearlessly dashed into its tumultuous waves. For a moment the spectators were in the most anxious doubt as to the result; for, though none could pull a stronger oar, yet the boat in crossing a distance equal to its own length was swept down 200 yards. Ten yards more would have dashed them to atoms on the lower stone wall. But they were now in comparatively quiet water; and availing themselves of this, they pulled up again to the park, in the space between two currents, and passed, with a little less difficulty, though in the same manner, the second and third streams, and at length reached the houses. The spectators gave them three hearty cheers. By this time the Kerrs had been left scarcely three feet of ground to stand on, under the back wall of the houses. A pleasing sight it was to see the boat touch that tiny strand, and the despairing family taken on board. How anxiously did the spectators watch every motion of the little boat, that was now so crowded as very much to impede the rowers. They crossed the first two streams, and finally drew up for the last and dreadful trial. There the frail bark was again whirled down; and notwithstanding all their exertions, the stern just touched the wall. The prow however was in stiller water; one desperate pull,—she sprang forward in safety, and a few more strokes of the oar landed the poor people amongst fifty or sixty of their assembled friends. After mutual greetings and embraces, and many tears of gratitude, old Kerr related his simple story. "Seeing their retreat cut off by the flood, they attempted to wade ashore. But the nearer the shore, the deeper and more powerful was the current. The moment was awful. The torrent increased on all sides, and night, dark night, was spread over them. The stream began to be too deep for the niece, a girl of twelve years of age,—she lost heart and began to sink. At this alarming crisis Kerr seized the trembling girl, and placed her on his back, and shoulder to shoulder with his wife, he providentially, but with the greatest difficulty, regained his own house. Between eight and nine o'clock he groped his way, and led his wife and niece up into the garret. He could not tell how long they remained there, but supposed it might be till about two o'clock next morning, when the roof began to fail. To avoid being crushed to death, he worked anxiously till he drove down the partition separating them from the adjoining house. Fortunately for him it was composed of wood and clay, and a partial failure he found in it very much facilitated his operations. Having made their way good, they remained there till about eight o'clock in the morning, when the strength of the water without became so great that it bent inwards the bolt of the lock of the house-door, till it had no greater hold of the staple than the eighth-part of an inch. Aware, that if the door should give way the back wall of the house would be swept down by the rush of the water inwards, and that they would be crushed to atoms, he rummaged the garret and fortunately found a bit of board and a few nails; and standing on the stairs, he placed one end of it against the door and the other on the hatch, forming the entrance to the garret, and so nailed it firmly down. At last the roof of the second house began to crack over their heads, and Kerr forced a way for himself and his companions through the thatch as has been already told."
Poor Funns and his family were not yet rescued from their little island; and the boat was declared to be too small and weak for so desperate a voyage. It was therefore determined to row to a spot where a larger boat was moored. To effect this, they were compelled to act precisely as they had done in proceeding to rescue the Kerrs. But unfortunately, on entering the third stream, they permitted the boat to glide down with it, in the hope that it would carry them in safety through the gate of the field, and across the road into that beyond it. In this, however, they were mistaken, and the boat was swamped. Fortunately for them, they were carried into smooth water, and by wading shoulder deep they reached the large boat.
Having secured the small boat, they attempted to drag the large one through the gateway against the stream; but it soon filled with water and swamped, and, in spite of all their exertions, they found it impossible to get it up. The small boat was now all they had to trust to, and this was next caught by the strong stream and overwhelmed in a moment; and had not the men, most providentially, caught and clung to a haycock that happened to be floating past, they must have been lost. They were carried along till it stuck on some young alder trees, when each of them grasped a bough, and the haycock sailed away, leaving them among the weak and brittle branches. They had been here about two hours, when one of the men being unable to hold on longer by the boughs, let himself gently down into the water with the hope of finding bottom; when, to his surprise, he found that the small boat had actually drifted to the root of the very tree to which they had been carried. Some salmon nets and ropes had also, by the strangest accident, been lodged there. The man contrived to pull up one of these with his foot, and making a noose, and slipping it on his great toe, he descended once more, and managed to fix the rope round the stern of the boat, which was then safely hauled up, the oars, being fixed to the side, being also saved. The boat was returned to Mr. Suter's and fresh manned, when it proceeded to a house occupied by a family of the name of Cumin, consisting of an old couple, their daughter, and grandson. By the time they reached the cottage, its western side was entirely gone, and the boat was pushed in at the gap. Not a sound was heard within, and they suspected that all were drowned; but, on looking through a hole in a partition, they discovered the unhappy inmates roosted, like fowls, on the beams of the roof. They were, one by one, transferred safely to the boat, half dead with cold; and melancholy to relate, the old man's mind, being too much enfeebled to withstand the agonizing apprehensions he had suffered, was now utterly deranged.
[Picture: Rescuing cottagers]
The poor Funns' were still the last to be relieved. They and their cattle were clustered on their little speck of land; and the poor quadrupeds, being chilled by standing so long in the water, were continually pressing inwards on them. It was between six and seven o'clock, the weather was clearer, and the waters were subsiding. The task being the most difficult of all, none but the most skilful rowers were allowed to undertake it. One wide inundation stretched from Monro's house to the tiny spot where Funns and his family were; and five tremendously tumultuous streams raged through it with elevated waves. The moment they dashed into the first of them they were whirled down for a great way; but having once got through it, they pulled up in the quieter water beyond, to prepare for the next; and in doing so, Sergeant Grant stood in the prow, and with a long rope, the end of which was fixed to the boat, and wherever he thought he had footing, he sprang out and dragged them up. The rest followed his example, and in this way they were enabled to start afresh with a sufficient advantage, and they crossed all the outer streams in the same manner. The last they encountered, being towards the middle of the flood, was fearful, and carried them very far down. But Funns himself, overjoyed to behold them, waded towards them, and gave them his best help to drag up the boat again. Glad was he to see his wife and children safely set in the boat. The perils of their return were not few; but they were at length happily landed.
These examples will suffice to show the nature and extent of the great floods of Moray. The inundation covered a space of something more than twenty miles in the Plain of Forres, and, as it was expressively remarked by one of the sufferers, "Before these floods was the Garden of Eden and behind them a desolate wilderness." And how often did the beautiful expression of the Psalmist occur to them: "The floods have lifted up, O Lord, the floods have lifted up their voice; the floods lift up their waves. The Lord on high is mightier than the noise of many waters; yea, than the mighty waves of the sea." Ps. xciii. 3, 4.
But it is not in Scotland alone that the terrors of the floods are experienced. All rivers which rise in high and cold regions, and pass into warm lowlands, are naturally very liable to overflow their bounds. A remarkable example is afforded by the river Rhone, which rises in the glaciers of Switzerland; and, after passing through the lake of Geneva, descends into the south-eastern departments of France,—a very level district, where the climate is mild and genial. Rapid meltings of the ice in Switzerland, or heavy falls of rain or snow in that country, greatly affect this river; and never, perhaps, were the effects more dreadful than in the inundations of 1840. At Lyons, where the Rhone joins the Saone, the most lamentable scenes took place. Not only were the whole of the low-lying lands in the vicinity of the city completely desolated, hundreds of houses overturned, and many cattle swept away, but the waters reached the city itself, bursting into the gas conduits, and thus leaving the people in darkness, and rising to a great height in the streets. The destruction of property, both in-doors and out-of-doors, was immense, and the loss of life appalling. Charitable people and public servants went about in boats laden with provisions, which were sent, at the expense of the magistrates and clergy, to the starving families pent up in their several abodes, where many of them remained in total darkness by night, and under hourly expectation that the foundations of their houses would give way beneath the rushing waters. In fact, numbers of houses, and even whole streets, were in this way sapped and overturned. Some of the people had fled to the heights near the city, at the first rising of the waters, but there they were reduced to the greatest extremities for want of food, and signal shots were heard from them continually. This miserable state of things lasted from the beginning of November until the 20th or 21st of the same month. At the same time the Rhone appeared like a succession of immense lakes from Lyons to Avignon, and from Avignon to the sea. A letter from Nismes, a little to the west of Avignon, thus described the scene:—
"As far as the view extends we perceive but one sheet of water, in the midst of which appear the tops of trees and houses, with the miserable inhabitants perched upon them. At Valabregue, an island on the Rhone, they have hung out a black banner from the church-yard, nearly two thousand persons being assembled in that spot, which is on an elevation. Steam-boats are attempting to carry bread to Valabregue, and other similarly situated places, but can scarcely effect it from the inequality of the ground. For ten days the rains have never ceased. The space covered by the waters near Avignon is calculated at about thirty-six leagues in length and sixty leagues in breadth. Human bodies are seen passing continually on the waters."
From the 10th to the 20th of November the Rhone fell several inches each day, but always rose again somewhat during the night. It began permanently to decline on the 20th, and in a few days the streets were exposed to view, with about a foot of mud on them. The loss of life and property, through this calamity, are almost incalculable.
A still grander display of the power and extent of inundations is afforded by the American rivers. The mighty waters of the Mississippi, (a river, whose course extends for several thousand miles,) when swelled, and overflowing their banks, present a wonderful spectacle. Unlike the mountain-torrents, and small rivers, of other parts of the world, the Mississippi rises slowly, continuing for several weeks to increase at the rate of about an inch in a day. When at its height, it undergoes little change for some days, and after this subsides as slowly as it rose. A flood generally lasts from four to six weeks, though it sometimes extends to two months. The American naturalist, Audubon, has given a striking account of the rush of waters overspreading the land when once this mighty river has begun to overflow its banks:—
"No sooner has the water reached the upper part of the banks, than it rushes out, and overspreads the whole of the neighbouring swamps, presenting an ocean overgrown with stupendous forest trees. So sudden is the calamity that every individual, whether man or beast, has to exert his utmost ingenuity to enable him to escape from the dreaded element. The Indian quickly removes to the hills of the interior, the cattle and game swim to the different strips of land that remain uncovered in the midst of the flood, or attempt to force their way through the waters until they perish from fatigue. Along the banks of the river the inhabitants have rafts ready-made, on which they remove themselves, their cattle, and their provisions, and which they then fasten with ropes or grape-vines to the larger trees, while they contemplate the melancholy spectacle presented by the current, as it carries off their houses and wood-yards piece by piece. Some, who have nothing to lose, and are usually known by the name of Squatters, take this opportunity of traversing the woods in canoes, for the purpose of procuring game, and particularly the skins of animals, such as the deer and bear, which may be converted into money. They resort to the low ridges surrounded by the waters, and destroy thousands of deer, merely for their skins, leaving the flesh to putrify.
"The river itself, rolling its swollen waters along, presents a spectacle of the most imposing nature. Although no large vessel, unless propelled by steam, can now make its way against the current, it is seen covered by boats laden with produce, which, running out from all the smaller streams, float silently towards the city of New Orleans, their owners, meanwhile, not very well assured of finding a landing-place even there. The water is covered with yellow foam and pumice, the latter having floated from the rocky mountains of the north-west. The eddies are larger and more powerful than ever. Here and there tracts of forest are observed undermined, the trees gradually giving way, and falling into the stream. Cattle, horses, bears, and deer are seen at times attempting to swim across the impetuous mass of foaming and boiling water; whilst, here and there, a vulture or an eagle is observed perched on a bloated carcass, tearing it up in pieces, as regardless of the flood, as on former occasions it would have been of the numerous sawyers and planters with which the surface of the river is covered when the water is low. Even the steamer is frequently distressed. The numberless trees and logs that float along, break its paddles, and retard its progress. Besides it is on such occasions difficult to procure fuel to maintain its fires."
In certain parts, the shores of the Mississippi are protected by artificial barriers called Levees. In such places, during a flood, the whole population of the district is engaged in strengthening these barriers, each proprietor being in great alarm lest a crevasse should open and let in the waters upon his fields. In spite of all exertions this disaster generally happens: the torrent rushes impetuously over the plantations, and lays waste the most luxuriant crops.
The mighty changes effected by the inundations of the Mississippi are little known until the waters begin to subside. Large streams are then found to exist where none had formerly been. These are called by navigators short cuts, and some of them are so considerable as to interfere with the navigation of the Mississippi. Large sand-banks are also completely removed by the impetuous whirl of the waters, and are deposited in other places. Some appear quite new to the navigator, who has to mark their situation and bearings in his log-book. Trees on the margin of the river have either disappeared, or are tottering and bending over the stream preparatory to their fall. The earth is everywhere covered by a deep deposit of muddy loam, which, in drying, splits into deep and narrow chasms, forming a sort of network, from which, in warm weather, noxious exhalations rise, filling the atmosphere with a dense fog. The Squatter, shouldering his rifle, makes his way through the morass in search of his lost stock, to drive the survivors home and save the skins of the drowned. New fences have everywhere to be formed, and new houses erected; to save which from a like disaster, the settler places them on a raised platform, supported by pillars made of the trunks of trees. "The lands must be ploughed anew; and if the season is not too far advanced, a crop of corn and potatoes may yet be raised. But the rich prospects of the planter are blasted. The traveller is impeded in his journey, the creeks and smaller streams having broken up their banks in a degree proportionate to their size. A bank of sand, which seems firm and secure, suddenly gives way beneath the traveller's horse, and the next moment the animal has sunk in the quicksand, either to the chest in front, or to the crupper behind, leaving its master in a situation not to be envied."
[Picture: Mists in the Valley]
CHAPTER III.
VARIOUS FORMS OP CLOUDS—THE CIRRUS, OR CURL-CLOUD—THE CUMULUS, OR STACKEN-CLOUD—THE STRATUS, OR FALL-CLOUD—THE CIRRO-CUMULUS, OR SONDER-CLOUD—THE CIRRO-STRATUS, OR WANE-CLOUD—THE CUMULO-STRATUS, OR TWAIN-CLOUD—THE NIMBUS, OR RAIN-CLOUD—ARRANGEMENT OF RAIN-CLOUDS—APPEARANCES OF A DISTANT SHOWER—SCUD—CAUSE OF RAIN—FORMATION OF CLOUDS—MISTS—HEIGHTS OF CLOUDS—APPEARANCE OF THE SKY ABOVE THE CLOUDS.
Many persons are apt to suppose that the clouds are among the most fitful and irregular appearances in the world; fleeting and unstable in their nature, uncertain in their forms, apparently subject to no fixed laws, and obedient neither to times nor seasons. Attentive observers, however, have proved that the beauty and harmony which are everywhere found to prevail in nature when rightly understood, can also be traced, even in the clouds. Although very much still remains to be discovered respecting them, yet it is found that, like all the other natural productions, they admit of being arranged and classified. So obvious was this to persons whose interest it is to observe the weather, that, long before scientific men had studied the subject, country people had noticed the different forms of clouds, and had learned to distinguish them by different names.
The first scientific man who made the clouds the object of his particular study, was Luke Howard, who, from an attentive consideration of their forms and appearances, found that they might all be arranged under three simple or primary forms, namely:—
1. The Cirrus—so called from its resemblance to a curled lock of hair. (Figures, 1, 2; page 77.)
2. The Cumulus, from the heaped appearance presented by the convex masses which form this cloud. (Figure 7.)
3. The Stratus, from its spreading out horizontally in a continuous layer, and increasing from below. (Figure 10.)
These three primary forms are subject to four modifications:—
The first is the Cirro-cumulus, consisting of small roundish and well-defined masses, in close horizontal arrangement. (Figure 3.)
[Picture: Various forms of clouds]
The second is the Cirro-Stratus, and the masses which compose it are small and rounded, but thinned off towards a part, or towards the whole of their circumference. They are sometimes separate, and sometimes in groups. (Figures 4, 5, 6.)
The third is the Cumulo-Stratus, which is made up of the cirro-stratus blended with the cumulus. (Figure 8.)
The fourth is the Cumulo-Cirro-Stratus, or Nimbus. This is the true rain-cloud, or system of clouds from which rain is falling. (Figure 9.)
The term modification applies to the structure or manner in which a given mass of cloud is made up, and not to its precise form or size, which in most clouds varies every instant. Mr. Howard remarks, that it may be at first difficult to distinguish one modification from another, or to trace the narrow limits which sometimes separate the different modifications; but a moderate acquaintance with the subject will soon enable any one to point out the various forms, and to a great extent to judge of the state of the weather by them. In order, therefore, to assist the reader in gaining a certain amount of knowledge on this interesting subject, it may be useful to state more fully the various phenomena of the different forms of clouds already enumerated.
[Picture: The Cirrus, or curl-cloud]
The Cirrus occurs in very great variety, and in some states of the air is constantly changing. It is the first cloud that appears in serene weather, and is always at a great height. The first traces of the cirrus are some fine whitish threads, delicately-pencilled on a clear blue sky; and as they increase in length others frequently appear at the sides, until numerous branches are formed, extending in all directions. Sometimes these lines cross each other and form a sort of delicate net-work. In dry weather the cirrus is sharp, defined, and fibrous in texture, the lines vanishing off in fine points. When the air is damp this cloud may be seen in the intervals of rain, but is not well defined, and the lines are much less fibrous. Such cirri as these often grow into other varieties of cloud, and are frequently followed by rain.
The cirrus may last a few minutes only, or continue for hours. Its duration is shortest when near other clouds. Although it appears to be stationary, it has some connexion with the motions of the atmosphere; for whenever, in fair weather, light variable breezes prevail, cirri are generally present. When they appear in wet weather, they quickly pass into the cirro-stratus.
According to Dalton, these clouds are from three to five miles above the earth's surface. When viewed from the summits of the highest mountains they appear as distant as from the plains. Another proof of their great height is, their continuing to be tinged by the sun's rays in the evening twilight with the most vivid colours, while the denser clouds are in the deepest shade.
The cirrus appears to be stationary; but, on comparison with a fixed object, it will sometimes be found to make considerable progress.
THE CUMULUS, OR STACKEN-CLOUD.
"And now the mists from earth are clouds in heaven: Clouds, slowly castellating in a calm Sublimer than a storm; while brighter breathes O'er the whole firmament the breadth of blue, Because of that excessive purity Of all those hanging snow-white palaces, A gentle contrast, but with power divine."
The Cumulus is a day cloud; it usually has a dense, compact appearance, and moves with the wind. In the latter part of a clear morning a small irregular spot appears suddenly at a moderate elevation. This is the nucleus or commencement of the cloud, the upper part of which soon becomes rounded and well defined, while the lower forms an irregular straight line. The cloud evidently increases in size on the convex surface, one heap succeeding another, until a pile of cloud is raised or stacked into one large and elevated mass, or stacken-cloud, of stupendous magnitude and beauty, disclosing mountain summits tipped with the brightest silver; the whole floating along with its point to the sky, while the lower surface continues parallel with the horizon.
[Picture: The Cumulus, or stacken-cloud]
When several cumuli are present, they are separated by distances proportioned to their size: the smaller cumuli crowding the sky, while the larger ones are further apart. But the bases always range in the same line; and the increase of each cloud keeps pace with that of its neighbour, the intervening spaces remaining clear.
The cumulus often attains its greatest size early in the afternoon, when the heat of the day is most felt. As the sun declines, this cloud gradually decreases, retaining, however, its characteristic form till towards sunset, when it is, more or less, hastily broken up and disappears, leaving the sky clear as in the early part of the morning. Its tints are often vivid, and pass one into the other in a most pleasing manner, during this last hour of its existence.
This cloud accompanies and foretells fine weather. In changeable weather it sometimes evaporates almost as soon as it is formed; or it appears suddenly, and then soon passes off to some other modification.
In fair weather this cloud has a moderate elevation and extent, and a well-defined rounded surface. Before rain it increases more rapidly than at other times, and appears lower in the atmosphere, with its surface full of loose fleeces.
The formation of large cumuli to leeward, in a strong wind, indicates the approach of a calm with rain. When they do not disappear or subside about sun-set, but continue to rise, thunder is to be expected in the night.
Independently of the beauty and magnificence which this description of cloud adds to the face of nature, it serves to screen the earth from the direct rays of the sun; by its multiplied reflections to diffuse and, as it were, economise the light; and also to convey immense stores of vapour from the place of its origin to a region in which moisture may be wanted.
THE STRATUS, OR FALL-CLOUD.
As the Cumulus belongs to the day, so does the Stratus to the night. It is the lowest of all the clouds, and actually rests upon the earth, or the surface of water. It is of variable extent and thickness, and is called Stratus, a bed or covering. It is generally formed by the sinking of vapour in the atmosphere, and on this account has been called Fall-cloud. It comprehends all those level, creeping mists, which, in calm evenings, spread like an inundation from the valleys, lakes, and rivers, to the higher ground. {85} But on the return of the sun the beautiful level surface of this cloud begins to put on the appearance of cumulus, the whole, at the same time, rising from the ground like a magnificent curtain. As the cloud ascends, it is broken up and evaporates or passes off with the morning breeze. The stratus has long been regarded as the harbinger of fine weather; and, indeed, there are few days in the year more serene than those whose morning breaks out through a stratus.
[Picture: The Stratus, or fall-cloud]
THE CIRRO-CUMULUS, OR SONDER-CLOUD.
The cirrus having continued for some time increasing or stationary, usually passes either to the cirro-cumulus or to the cirro-stratus, at the same time descending to a lower station in the atmosphere.
The Cirro-cumulus is formed from a cirrus, or a number of small separate cirri, passing into roundish masses, in which the extent of the cirrus is no longer to be seen. This change takes place either throughout the whole mass at once, or progressively from one extremity to the other. In either case the same effect is produced on a number of neighbouring cirri at the same time, and in the same order. It appears, in some instances, to be hastened by the approach of other clouds.
[Picture: The Cirro-Cumulus, or sonder-cloud]
The cirro-cumulus forms a very beautiful sky, exhibiting sometimes numerous distinct beds of small connected clouds floating at different heights. It is frequent in summer, and accompanies warm, dry weather. On a fine summer's evening the small masses which compose this cloud, are often well defined, and lying quite asunder, or separate from one another; and on this account the term sonder-cloud has been applied to this modification. The whole sky is sometimes covered with these small masses. They are occasionally, and more sparingly, seen in the intervals of showers, and in winter.
Bloomfield, in the following beautiful lines, has noticed the appearance of the sonder-cloud:—
"For yet above these wafted clouds are seen (In a remoter sky still more serene) Others, detach'd in ranges through the air, Spotless as snow, and countless as they're fair; Scatter'd immensely wide from east to west, The beauteous semblance of a flock at rest: These, to the raptur'd mind, aloud proclaim The mighty Shepherd's everlasting name."
This cloud may either evaporate or disappear, or it may pass to the cirrus, or sink lower and become a cirro-stratus. In stormy weather, before thunder, a cirro-cumulus often appears, composed of very dense and compact round bodies, in very close arrangement. When accompanied by the cumulo-stratus, it is a sure indication of a coming storm.
THE CIRRO-STRATUS, OR WANE-CLOUD.
This cloud appears to be formed from the fibres of the cirrus sinking into a horizontal position, at the same time that they approach each other sideways. This cloud is to be distinguished by its flatness and great horizontal extension, in proportion to its height; a character which it always retains, under all its various forms. As this cloud is generally changing its figure, and slowly sinking, it has been called the wane-cloud. A collection of these clouds, when seen in the distance, frequently give the idea of shoals of fish. Sometimes the whole sky is so mottled with them, as to obtain for it the name of the mackerel-back sky, from its great resemblance to the back of that fish. Sometimes they assume an arrangement like discs piled obliquely on each other. But in this, as in other instances, the structure must be attended to rather than the form, for this varies much, presenting, at times, the appearance of parallel bars or interwoven streaks, like the grain of polished wood. It is thick in the middle and thinned off towards the edge.
[Picture: The Cirro-Stratus, or wane-cloud]
These clouds precede wind and rain. The near or distant approach of a storm may often be judged of from their greater or less abundance and duration. They are almost always to be seen in the intervals of storms. Sometimes the cirro-stratus, and the cirro-cumulus, appear together in the sky, and even alternate with each other in the same cloud, presenting many curious changes; and a judgment may be formed of the weather likely to ensue, by observing which prevails at last.
The cirro-stratus most frequently forms the solar and lunar halo. Hence the reason of the prognostics of bad weather commonly drawn from the appearance of halos.
THE CUMULO-STRATUS, OR TWAIN-CLOUD.
[Picture: The Cumulo-Stratus, or twain-cloud]
This is a blending of two kinds of cloud (hence the name of twain-cloud,) and it often presents a grand and beautiful appearance, being a collection of large fleecy clouds overhanging a flat stratum or base. When a cumulus increases rapidly a cumulo-stratus frequently forms around its summit, resting thereon as on a mountain, while the former cloud continues to be seen, in some degree, through it. This state of things does not continue long. The cumulo-stratus speedily becomes denser and spreads, while the upper part of the cumulus extends likewise, and passes into it, the base continuing as it was. A large, lofty, dense cloud is thus formed which may be compared to a mushroom with a very thick, short stem. The cumulo-stratus, when well formed and seen singly, and in profile, is quite as beautiful an object as the cumulus. Mr. Howard has occasionally seen specimens constructed almost as finely as a Corinthian capital; the summit throwing a well-defined shadow upon the parts beneath. It is sometimes built up to a great height. The finest examples occur between the first appearance of the fleecy cumuli and the commencement of rain, while the lower atmosphere is comparatively dry, and during the approach of thunder storms. The appearance of the cumulo-stratus, among ranges of hills, presents some interesting phenomena. It appears like a curtain dropping among them and enveloping their summits; the hills reminding the spectator of the massy Egyptian columns which support the flat-roofed temples of Thebes. But when a whole sky is crowded with these clouds, and the cumulus rises behind them, and is seen through the interstices, the whole, as it passes off in the distant horizon, presents to the fancy mountains covered with snow, intersected with darker ridges, lakes of water, rocks and towers. Shakspeare seems to have referred to this modification in the well-known lines:—
"Sometimes we see a cloud that's dragonish; A vapour, sometimes, like a bear or lion, A towered citadel, a pendent rock, A forked mountain, a blue promontory, With trees upon 't that nod unto the world, And mock our eyes with air.— That which is now a horse, even with a thought The rack dislimns, and makes it indistinct As water is in water.
The distinct cumulo-stratus is formed in the interval between the first appearance of the fleecy cumulus and the commencement of rain, while the lower atmosphere is yet dry; also during the approach of thunder storms when it has frequently a reddish appearance. Its indistinct appearance is chiefly in the longer or shorter intervals of showers of rain, snow, or hail.
THE CUMULO-CIRRO-STRATUS; NIMBUS OR RAIN-CLOUD.
Clouds, in any one of the preceding forms, at the same degree of elevation, or two or more of these forms at different elevations, may increase and become so dense as completely to obscure the sky; this, to an inexperienced observer, would seem to indicate the speedy commencement of rain. But Mr. Howard is of opinion that clouds, while in any of the states above described, never let fall rain.
Before rain the clouds always undergo a change of appearance, sufficiently remarkable to give them a distinct character. This appearance, when the rain happens overhead, is but imperfectly seen; but from the observations of aeronauts, it appears that whenever a fall of rain occurs, and the sky is at the same time entirely overcast with clouds, there will be found to exist another stratum of clouds at a certain elevation above the former. So, also, when the sky is entirely overcast and rain is altogether or generally absent, the aeronaut, upon traversing the canopy immediately above him, is sure to enter upon an upper hemisphere either perfectly cloudless or nearly so. These remarks were, we believe, first made by Mr. M. Mason, and he states that they have been verified during many hundred ascents.
In October, 1837, two ascents were made by Mr. Mason, which well illustrate what has been said. On the 12th, "the sky was completely overspread with clouds, and torrents of rain fell incessantly during the whole of the day. Upon quitting the earth, the balloon was almost immediately enveloped in the clouds, through which it continued to work its way upwards for a few seconds. Upon emerging at the other side of this dense canopy, a vacant space, of some thousand feet in breadth, intervened, above which lay another stratum of a similar form and observing a similar character. As the rain, however, still continued to pour from this second layer of clouds, to preserve the correctness of the observation, a third layer should, by right, have existed at a still further elevation; which, accordingly, proved to be the case. On the subsequent occasion of the ascent of the same balloon, (October 17th,) an exactly similar condition of the atmosphere, with respect to clouds, prevailed; unaccompanied, however, with the slightest appearance of rain. No sooner had the balloon passed the layer of clouds immediately above the surface of the earth, than, as was anticipated, not a single cloud was to be found in the firmament beyond; an unbroken expanse of clear blue sky everywhere embracing the frothy plain that completely intercepted all view of the world beneath."
Mr. Howard had not the advantages of a balloon to assist his observations. He has noticed that during rain and before the arrival of the denser and lower clouds, or through their interstices, there exists, at a greater height, a thin light veil or a hazy appearance. When this has considerably increased, the lower clouds are seen to spread till they unite in all points and form one uniform sheet. The rain then commences, and the lower clouds arriving from the windward, move under this sheet and are successively lost in it. When the latter cease to arrive, or when the sheet breaks, letting through the sun-beams, every one's experience teaches him to expect that the rain will abate or leave off.
But there often follows an immediate and great addition to the quantity of cloud. At the same time the darkness becomes less, because the arrangement, which now returns, gives free passage to the rays of light; the lower broken clouds rise into cumuli, and the upper sheets put on the various forms of the cumulo-stratus, sometimes passing to the cirro-cumulus.
The various phenomena of the rain-cloud are best seen in a distant shower. If the cumulus be the only cloud at first visible, its upper part is seen to become tufted with cirri. Several adjacent clouds also approach and unite at its side. The cirri increase, extending upwards and sideways, after which the shower is seen to commence. At other times, the cirro-stratus is first formed above the cumulus, and their sudden union is attended with the production of cirri and rain. In either case the cirri spring up in proportion to the quantity of rain falling, and give the cloud a character by which it is easily known at great distances, and which has long been called by the name of nimbus.
When one of these arrives hastily with the wind, it brings but little rain, and frequently some hail or driven snow.
Since rain may be produced and continue to fall from the slightest obscuration of the sky by the nimbus, while a cumulus or a cumulo-stratus, of a very dark and threatening aspect, passes on without discharging any until some change of state takes place; it would seem as if nature had destined the latter as reservoirs, in which water is collected from extensive regions of the air for occasionally irrigating particular spots in dry seasons; and by means of which it is arrested, at times, in its descent in wet ones.
Although the nimbus is one of the least beautiful of clouds, it is, nevertheless, now and then adorned by the splendid colouring of the rainbow, which can only be seen in perfection when the dark surface of this cloud forms for it a background.
The small ragged clouds which are sometimes seen sailing rapidly through the air, are called scud. They consist of portions of a rain-cloud, probably broken up by the wind, and are dark or light according as the sun shines upon them. They are the usual harbingers of rain, and, as such, are called by various names, such as messengers, carriers, and water-waggons.
* * * * *
In attempting to explain the production of clouds and rain, it is necessary to observe that the subject is beset with difficulties—the discussion of which does not belong to this little volume; but the following notice of Dr. Hutton's theory may not be out of place.
It has been already stated, that the air supplies itself with moisture from the surface of the waters of the earth. This it continues to do at all temperatures, until it is so charged with vapour that it cannot contain any more. The air is then said to be saturated. Now, the quantity of moisture which a given bulk of air can contain, depends entirely upon the temperature of the air for the time being. The higher the temperature of the air the greater will be the quantity of vapour contained in it; and, although it may be perfectly invisible to the eye, on account of the elasticity which the heat imparts to it, yet it can easily be made visible by subtracting a portion of the heat. If, for example, a glass of cold water be suddenly brought into a warm room, moisture from the air will be condensed upon the outside of the glass in the form of dew. A similar change is supposed to take place when two currents of air having different temperatures, but both saturated with vapour, are mingled together; an excess of vapour is set free, which forms a cloud or falls down as rain. If the currents continue to mingle uniformly, "the clouds soon spread in all directions, so as to occupy the whole horizon; while the additional moisture, incessantly brought by the warmer current, keeps up a constant supply for condensation, and produces a great and continued deposition of moisture in the form of rain. By degrees, the currents completely intermingle, and acquire a uniform temperature; condensation then ceases; the clouds are re-dissolved; and the whole face of nature, after being cooled and refreshed by the necessary rain, is again enlivened by the sunshine, thus rendered still more agreeable by its contrast with the previous gloom."
If the cloud, produced by the mingling of two differently heated currents of moist air, happen to form in the upper regions of the sky, it may be heavier than its own bulk of air, and will consequently begin to sink. Should the atmosphere near the earth be less dense than the cloud, the latter will continue to descend till it touches the ground, where it forms a mist. If the vapour has been condensed rapidly and abundantly, the watery particles will form rain, hail, or snow, according to the temperature of the air through which they pass. But it may happen that the cloud, in descending, arrives in a warmer region than that in which it was formed: in this case, the condensed moisture may again become vapour, and ascend again to a region where condensation may again take place. |
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