CHAPTER VI.

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.

By means of rain and rain clouds we get that beautiful appearance so well known as the rainbow. In order to form some idea of the manner in which the rainbow is produced, it is necessary to know something of the manner in which light is composed. Sir Isaac Newton was the first philosopher who clearly explained the composition of light, as derived from the sun. He admitted a ray of the sun into a darkened room through a small hole in the window shutters; in front of this hole he placed a glass prism, and at a considerable distance behind the prism he placed a white screen. If there had been no prism between the hole and the screen, the ray of light would have proceeded in the direction of the dotted lines, and a bright spot would have fallen upon the floor of the room, as shown in the figure. But the effect of the prism is to refract or bend the ray out of its ordinary course, and in doing so it does not produce a white spot upon the screen, but a long streak of beautiful colours, in the order marked in the figure, red being at the bottom, then orange, yellow, green, blue, indigo, and violet at the top.

Decomposition of white light

In order to account for the production of these colours from a ray of light, Newton supposed that such a ray is actually made up of seven distinct colours, which being mixed in proper proportions neutralize or destroy each other. In order to account for the decomposition of the ray of white light by the prism, and for the lengthened form of the spectrum, as it is called, he supposed that each of the seven coloured rays was capable of being bent by the prism in a different manner from the rest. Thus, in the figure, the red appears to be less bent out of the direction of the original ray than the orange—the orange less than the yellow, and so on until we arrive at the violet, which is bent most of all.

It is scarcely necessary to remark, that these views were found to be correct, except as regards the number of colours in the solar spectrum; for it is now ascertained, with tolerable certainty, that there are only three primitive or pure colours in nature, and these are red, yellow, and blue; and it is supposed that by mingling two or more of these colours in various proportions, all the colours in nature are produced.

Now, to apply this explanation to the production of the rainbow, which is usually seen under the following circumstances:—The observer is placed with his back to the sun, and at some distance before him rain is falling,—the air between the sun and the rain being tolerably clear. He then often sees two circular arcs or bows immediately in front of him. The colours of the inner bow are the more striking and vivid of the two. Each exhibits the same series of colours as in the spectrum formed by the prism; namely, red, orange, yellow, green, blue, indigo, and violet; but the arrangement of these colours is different in the two bows, for while in the inner bow the lower edge is violet and the upper red, in the outer bow the lower edge is red and the upper violet. The production of both bows is due to the refraction and reflexion of light, the drops of rain forming, in fact, the prism which decomposes the white light of the sun. The colours in the rainbow have the same proportional breadth as the spaces in the prismatic spectrum. “The bow is, therefore,” as Sir D. Brewster remarks, “only an infinite number of prismatic spectra, arranged in the circumference of a circle; and it would be easy, by a circular arrangement of prisms, or by covering up all the central part of a large lens, to produce a small arch of exactly the same colours. All we require, therefore, to form a rainbow, is a great number of transparent bodies capable of forming a great number of prismatic spectra from the light of the sun.”

The manner in which the drops of rain act as prisms, may, perhaps, be better understood with the assistance of the following diagram. Suppose the two lower circles to represent drops of rain which assist in forming the primary bow, and the two upper circles similar drops which help to produce the secondary bow; and let S represent rays of the sun falling upon them. The rays of the sun fall upon every part of the drop; but, as those which pass through or near the centre come out on the opposite side and form a focus, they need not be taken into account. Those rays, however, which fall on the upper side of the drops, will be bent or refracted, the red rays least, and the violet most; and will fall upon the back of the drop in such a manner as to be reflected to the under part of the drop; on quitting which they will be again refracted, so as to be seen at E, where there will appear to the observer a prismatic spectrum with the red uppermost, and the violet undermost. These remarks apply to those drops only which form the upper part of the bow, but it is obvious that a similar reasoning applied to the drops to the right and left of the observer, will complete the bow. The inclination of the red ray and the violet ray to the sun’s rays, is 42° 2′ for the red, and 40° 17′ for the violet, so that the breadth of the primary bow is 1° 45′.

Thus it will be seen, that the primary bow is produced by two refractions, and one intermediate reflection of the rays that fall on the upper sides of the drops of rain. It is different with the rays which enter the drops below. The red and violet rays will be bent or refracted in different directions; and, after being twice reflected, will be again bent towards the eye of the observer at E; but in this case the violet forms the upper part, and the red the under part of the spectrum. The inclination of these rays to the sun’s rays at S, is 50° 58′ for the red ray, and 54° 10′ for the violet ray; so that the breadth of the bow is 3° 10′, and the distance between the primary and secondary bows is 8° 15′. Hence the secondary is formed in the outside of the primary bow, with its colours reversed, in consequence of their being produced by two reflexions and two refractions. The colours of the secondary bow are much fainter than those of the primary, because they undergo two reflexions instead of one.

There is something very wonderful in the rapidity and perfection with which these natural prisms, the falling drops of rain, produce these effects. In the inconceivably short space of time occupied by a drop falling through those parts of the sky which form the proper angles with the sun’s rays and the eye of the observer, the light enters the surface of the drop, undergoes within it one or two reflexions, two refractions and decompositions, and has reached the eye; and all this is done in a portion of time too small for the drop to have fallen through a space which we have the means of measuring.

It will be understood, that since the eyes of different observers cannot be in precisely the same place at the same time, no two observers can see the same rainbow; that is to say, the bow produced by one set of drops to the eye of one observer is produced by another set of drops to the eye of another observer.

A rainbow can never be greater than a semicircle, unless the spectator is on elevated ground; for if it were greater than a semicircle the centre of the bow would be above the horizon, while the sun, which must be in a line drawn through that centre and the eye of the observer, would be below the horizon: but in such a case, the sun could not shine on the drops of rain, and consequently there could be no rainbow.

When the rain cloud is of small extent only a portion of a bow is visible; when the cloud overspreads a large part of the sky a perfect bow appears. Sometimes the bow may be traced across a portion of blue sky, or it may appear to rest on the ground. In the former case, there are vapours in the air too thin to be seen, but sufficient to refract and reflect the rays of light; in the latter, the drops of rain, adhering to the grass and foliage, produce the same effect. A coloured bow, similar to that produced by rain, is sometimes seen in the spray of a fountain or of a water-fall, and also in mists that lie low upon the ground.

In mountainous and stormy regions rainbows are often seen to great advantage. In the islands off the Irish coast the author of “Letters from the Irish Islands,” describes the rainbow of winter “as gradually advancing before the lowering clouds, sweeping with majestic stride across the troubled ocean, then, as it gained the beach, and seemed almost within one’s grasp, vanishing amid the storm of which it had been the lovely but treacherous forerunner. It is, I suppose, a consequence of our situation, and the close connexion between sea and mountain, that the rainbows here are so frequent and so peculiarly beautiful. Of an amazing breadth, and of colours vivid beyond description, I know not whether most to admire this aërial phenomenon, when suspended in the western sky, one end of the bow sinks behind the Island of Boffin, while at the distance of several leagues the other rests upon the misty hills of Ennis Turc; or when, at a later hour of the day, it has appeared stretched across the ample sides of Mulbrea, penetrating far into the deep blue waters that flow at its base. With feelings of grateful recollection, too, we may hail the repeated visits of this heavenly messenger, occasionally as often as five or six times in the course of the same day, in a country exposed to such astonishing, and, at times, almost incessant floods of rain.”

The beauty of the rainbow is not the only reason why we should regard it with interest. The rainbow was appointed by God himself as a sign of the covenant of mercy, made with Noah and with all mankind, after the flood. The words in which this declaration was made to mankind, are recorded in the Book of Genesis, chap. ix. ver. 11 to 16.

Burnet, in his “Sacred Theory of the Earth,” has some remarks on the first appearance of the rainbow to the inhabitants of the earth after the deluge. He says, “How proper and how apposite a sign would this be for Providence to pitch upon, to confirm the promise made to Noah and his posterity, that the world should be no more destroyed by water! It had a secret connexion with the effect itself, and was so far a natural sign; but, however, appearing first after the deluge, and in a watery cloud, there was, methinks, a great easiness and propriety of application for such a purpose. And if we suppose, that while God Almighty was declaring his promise to Noah, and the sign of it, there appeared at the same time in the clouds a fair rainbow, that marvellous and beautiful meteor which Noah had never seen before; it could not but make a most lively impression upon him, quickening his faith, and giving him comfort and assurance that God would be stedfast to his promise.”

A rainbow is sometimes formed by the rays of the moon falling upon drops of rain, in the same manner as the solar rays, and refracted and reflected by the drops; but the colours are faint in consequence of the feeble light of the moon compared with that of the sun. A lunar rainbow has been thus described by an observer:—“The moon was truly ‘walking in brightness,’ brilliant as she could be, not a cloud was to be seen near her; and over against her, toward the north-west, or perhaps rather more to the north, was a rainbow, a vast arch, perfect in all its parts, not interrupted or broken as rainbows frequently are, but unremittedly visible from one horizon to the other. In order to give some idea of its extent, it is necessary to say, that, as I stood toward the western extremity of the parish of Stoke Newington, it seemed to take its rise from the west of Hampstead, and to end perhaps in the river Lea, the eastern boundary of Tottenham. Its colour was white, cloudy, or greyish, but a part of its western limb seemed to exhibit tints of a faint sickly green. After some time the moon became darkened by clouds, and the rainbow of course vanished.”

Lunar Rainbow

The brilliant colours of the solar rainbow are frequently produced by the clouds without any prismatic arrangement. The light of the sun is decomposed by a process called absorption: for example, white light is composed of red, yellow, and blue rays, in certain proportions; now, if in passing through, or falling upon any substance whatever, the red rays are stifled or absorbed, while the yellow and blue are allowed to pass or to be reflected, it is obvious that such a substance cannot appear white, because one of the elements of white light, namely, the red, is wanting; it must therefore appear of such a colour as results from the combination of yellow and blue; the substance will therefore appear green. So, also, when white light falls upon what we call a red surface, the yellow and blue rays are stifled or absorbed, leaving the red only to be reflected. Now, when we consider the various ways in which this absorption may take place; one or two, or all of the coloured rays being absorbed in every possible proportion, it is easy to form some idea of the manner by which the innumerable tints of the sky are produced.

It has been calculated, that, of the horizontal sunbeams which pass through two hundred miles of air, scarcely a two thousandth part reaches the earth. A densely formed cloud must therefore detain a much larger share; and those dark and sombre forms, which sometimes make the sky so gloomy, can only result from the abundant absorption of the solar light. The brilliant whiteness which their edges occasionally exhibit, must result from the more copious transmission of light, so that the depths of shade in a cloud may be regarded as comparative measures of the varied thickness of its mass.

Sometimes the clouds absorb equally all the solar rays, in which case the sun and moon appear through them perfectly white. Instances are recorded in which the sun appeared of a pale blue. It has also been observed to be orange at its upper part, while the lower was of a brilliant red.

The position from which clouds are seen, has much to do with their colours; and it seems difficult sometimes to believe that the clouds, which in the evening are seen drenched with crimson and gold, are the same we beheld absolutely colourless in the middle of the day.

In the immediate neighbourhood of the sun the most brilliant colours may be disclosed; and their vividness and intensity diminish, and at last disappear at some distance from it. Parry noticed some white fleecy clouds, which, at the distance of fifteen or twenty degrees from the sun, reflected from their edges the most soft and tender tints of yellow, bluish green, and lake; and as the clouds advanced the colours increased gradually, until they reached a sort of limit two degrees below the solar orb. As the current continued to transport them, the vividness of colour became weakened by almost insensible degrees until the whole assemblage of tints vanished.

“Who can venture to imitate, by the pencil, the endless varieties of red and orange and yellow which the setting sun discloses, and the magical illusions which all the day diversify the vast and varied space the eye travels over in rising gradually from the horizon to the upper sky? Those who have paid any attention to colours, must be aware of the difficulty of describing the various tints and shades that appear, and which are known to amount to many thousands.”

The rapid changes of colour which the clouds undergo, seem to depend on something more than change of position either in the cloud or in the sun. Forster mentions an instance of some detached cirro-cumuli being of a fine golden yellow, but in a single minute becoming deep red. On another occasion he saw the exact counterpart in a cirro-stratus, by its instantly changing from a beautiful red to a bright golden yellow. “What, indeed, can be more interesting, than when by the breaking out of the sun in gleams, a cloud which a moment before seemed only an unshapened mass devoid of all interest and beauty, is suddenly pierced by cataracts of light, and imbued with the most splendid colours, varying every instant in intensity? Numerous examples occur of this beautiful play of colour, which cannot but remind us of the phenomena displayed by the pigeon’s neck and the peacock’s tail, by opal and pearl.

“After the sun is set, the mild glow of his rays is still diffused over every part; and it has been remarked, that the clouds assume their brightest and most splendid colours a few minutes after it is below the horizon. It is in the finest weather that the colouring of the sky presents the most perfect examples of harmony, in tempestuous weather it being almost always inharmonious. At the time of a warm sun-setting, the whole hemisphere is influenced by the prevailing colour of the light. The snowy summits of the Alps appear about sunset of a most beautiful violet colour, approaching to light crimson or pink. It is remarkable, also, as an example of that general harmony which prevails in the material world, that the most glowing and magnificent skies occur when terrestrial objects put on their deepest and most splendid hues. It has also been observed, that it is not the change of vegetation only, which gives to the decaying charms of autumn their finest and most golden hues, but also the atmosphere and the peculiar lights and shadows which then prevail; and there can be no doubt, on the other hand, that our perception of beauty in the sky is very much influenced by the surrounding scenery. In autumn all is matured; and the rich hues of the ripened fruits and the changing foliage are rendered still more lovely by the warm haze which a fine day at that season presents. So, also, the earlier hues of spring have a transparency, and a thousand quivering lights, which in their turn harmonize with the light and flitting clouds and uncertain shadows which then prevail.” [155]

Decorative picture of lady by river

Foot-print of a bird, and impression of rain-drops sand-stone

CHAPTER VII.

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.

Water, in the state of rain, hail, snow, or dew, is generally the only substance which falls from the atmosphere upon the earth. There are, however, many well authenticated instances of various substances being showered down upon the land, to the great alarm of persons who were ignorant that the powerful action of the wind was, perhaps, the chief cause of the strange visitations to which we allude.

We read of showers of sand, mud, sulphur, blood, fishes, frogs, insects, and stones; and it may be useful, as well as interesting, to quote a few examples of each description of shower.

On the west coast of Africa, between Cape Bojador and Cape Verd, and thence outwards, the land, during the dry season, consists of little else but dust or sand, which, on account of its extreme fineness, is raised into the atmosphere by the slightest current of air; while a moderate wind will convey it to so considerable a distance as even to annoy ships crossing the Atlantic. On the 14th and 15th January, 1839, the Prussian ship, Princess Louisa, being in N. lat. 24° 20′, and W. long. 26° 42′, had her sails made quite yellow by the fine sand which covered them. This effect was produced when the distance from land was as much as from 12° to 20°. About a fortnight after the time when this ship crossed these parts of the Atlantic, a similar effect was produced on board the English ship Roxburgh. One of the passengers, the Rev. W. B. Clarke, says:—“The sky was overcast, and the weather thick and insufferably oppressive, though the thermometer was only 72°. At 3 p.m. Feb. 4, the wind suddenly lulled into a calm; then rose from the SW. accompanied by rain, and the air appeared to be filled with dust, which affected the eyes of the passengers and crew. The weather was clear and fine, and the powder which covered the sails was of a reddish-brown colour, resembling the ashes ejected from Vesuvius; and Mr. Clarke thinks that this dust may have proceeded from the volcanic island of Fogo, one of the Cape de Verds, about forty-five miles from the place where the ship then was.

In countries which are subject to long-continued droughts the soil is frequently converted into dust, which, being carried away by the winds, leaves the land barren. The climate of Buenos Ayres, in South America, has of late years been subject to such droughts, as to disappoint the hopes of the husbandman and the breeder of cattle. In the early part of 1832, the drought had reached to such a height as to convert the whole province into one continued bleak and dreary desert. The clouds of dust raised by the winds were so dense as completely to obscure the sun at mid-day, and envelope the inhabitants in almost total darkness. When the rains at length commenced, in March, the water, in its passage through the air, intermingled so completely with the dust suspended in it, as to descend in the form of showers of mud; and, on some occasions, gave to the whole exterior of the houses the appearance of having been plastered over with earth. Many flocks of sheep were smothered on these occasions, in a similar manner as in the snow-storms which occur in the mountainous districts of Scotland.

Showers of sulphur, or yellow rain, have fallen at different times in various parts of Europe; and sometimes, when falling by night, they have appeared luminous, to the great alarm of the observers. Yellow rain has been accounted for in the following way:—The pollen, or impregnating seed-dust of the flowers of the fir, birch, juniper, and other trees, is of a yellow colour, and this pollen, by the action of the wind, is carried to a considerable distance, and descends with falling rain. This yellow rain has also been found impregnated with sulphur; and during a shower of this kind which once fell in Germany, matches were made by being dipped in it.

Many examples of luminous rain are recorded on good authority. One of the latest instances is mentioned by Dr. Morel Deville, of Paris, who on the 1st of November, 1844, at half-past eight o’clock in the evening, during a heavy fall of rain, noticed, as he was crossing the court of the College Louis-le-Grand, that the drops, on coming in contact with the ground, emitted sparks and tufts (aigrettes) of light, accompanied by a rustling and crackling noise; a smell of phosphorus having been immediately after perceptible. The phenomenon was seen three times. At the same hour a remarkable brightness was seen in the northern sky.

An officer of the Algerian army states, that during a violent storm on the 20th September, 1840, the drops of rain that fell on the beards and mustachios of the men were luminous. When the hair was wiped the appearance ceased; but was renewed the moment any fresh drops fell on it.

But of all these remarkable showers, the greatest alarm has been occasioned by red rain, or showers of blood as they have been ignorantly called. In the year 1608, considerable alarm was excited in the city of Aix and its vicinity by the appearance of large red drops upon the walls of the cemetery of the greater church, which is near the walls of the city, upon the walls of the city itself, and also upon the walls of villas, hamlets, and towns, for some miles round the city. The husbandmen are said to have been so alarmed, that they left their labour in the fields and fled for safety into the neighbouring houses; and a report was set on foot, that the appearance was produced by demons or witches shedding the blood of innocent babes. M. Peiresc, thinking this story of a bloody shower to be scarcely reconcileable with the goodness and providence of God, accidentally discovered, as he thought, the true cause of the phenomenon. He had found, some months before, a chrysalis of remarkable size and form, which he had enclosed in a box; he thought no more of it, until hearing a buzz within the box, he opened it, and perceived that the chrysalis had been changed into a beautiful butterfly, which immediately flew away, leaving at the bottom of the box a red drop of the size of a shilling. As this happened about the time when the shower was supposed to have fallen, and when multitudes of those insects were observed fluttering through the air in every direction, he concluded that the drops in question were emitted by them when they alighted upon the walls. He, therefore, examined the drops again, and remarked that they were not upon the upper surfaces of stones and buildings, as they would have been if a shower of blood had fallen from the sky, but rather in cavities and holes where insects might nestle. He also noticed that they were to be seen upon the walls of those houses only which were near the fields; and not upon the more elevated parts of them, but only up to the same moderate height at which butterflies were accustomed to flutter. This was, no doubt, the correct explanation of the phenomenon in question; for it is a curious and well-ascertained fact, that when insects are evolved from the pupa state, they always discharge some substance, which, in many butterflies, is of a red colour, resembling blood, while in several moths it is orange or whitish.

It appears, however, from the researches of M. Ehrenberg, a distinguished microscopic observer, that the appearances of blood which have at different times been observed in Arabia, Siberia, and other places, are not to be attributed to one, but to various causes. From his account, it appears that rivers have flowed suddenly with red or bloody water, without any previous rain of that colour having fallen; that lakes or stagnant-waters were suddenly or gradually coloured without previous blood-rain; that dew, rain, snow, hail, and shot-stars, occasionally fall from the air red-coloured, as blood-dew, blood-rain, and clotted blood; and, lastly, that the atmosphere is occasionally loaded with red dust, by which the rain accidentally assumes the appearance of blood-rain, in consequence of which rivers and stagnant waters assume a red colour.

The blood-red colour sometimes exhibited by pools, was first satisfactorily explained at the close of the last century. Girod Chantran, observing the water of a pond to be of a brilliant red colour, examined it with the microscope, and found that the sanguine hue resulted from the presence of innumerable animalculæ, not visible to the naked eye. But, before this investigation, Linnæus and other naturalists had shown that red infusoria were capable of giving that colour to water which, in early times, and still, we fear, in remote districts, was supposed to forebode great calamities. In the year 1815 an instance of this superstitious dread occurred in the south of Prussia. A number of red, violet, or grass-green spots were observed in a lake near Lubotin, about the end of harvest. In winter the ice was coloured in the same manner at the surface, while beneath it was colourless. The inhabitants, in great dismay, anticipated a variety of disasters from the appearance; but it fortunately happened that the celebrated chemist Klaproth, hearing of the circumstance, undertook an examination of the waters of the lake. He found them to contain an albuminous vegetable matter, with a particular colouring matter similar to indigo, produced, probably, by the decomposition of vegetables in harvest; while the change of colour from green to violet and red, he explained by the absorption of more or less oxygen. A few years ago the blood-red waters of a Siberian lake were carefully examined by M. Ehrenberg, and found to contain multitudes of infusoria, by the presence of which this remarkable appearance was accounted for. Thus it appears that both animals and vegetables are concerned in giving a peculiar tint to water. It has also been ascertained that red snow is chiefly occasioned by the presence of red animalculæ.

Showers of fish and frogs are by no means uncommon, especially in India. One of these showers, which fell about twenty miles south of Calcutta, is thus noticed by an observer:—“About two o’clock, p.m., of the 20th inst., (Sept. 1839,) we had a very smart shower of rain, and with it descended a quantity of live fish, about three inches in length, and all of one kind only. They fell in a straight line on the road from my house to the tank which is about forty or fifty yards distant. Those which fell on the hard ground were, as a matter of course, killed from the fall, but those which fell where there was grass sustained no injury; and I picked up a large quantity of them, ‘alive and kicking,’ and let them go into my tank. The most strange thing that ever struck me in connexion with this event, was, that the fish did not fall helter skelter, everywhere, or ‘here and there;’ but they fell in a straight line, not more than a cubit in breadth.” Another shower is said to have taken place at a village near Allahabad, in the month of May. About noon, the wind being in the west, and a few distant clouds visible, a blast of high wind came on, accompanied with so much dust as to change the tint of the atmosphere to a reddish hue. The blast appeared to extend in breadth four hundred yards, and was so violent that many large trees were blown down. When the storm had passed over, the ground, south of the village, was found to be covered with fish, not less than three or four thousand in number. They all belonged to a species well known in India, and were about a span in length. They were all dead and dry.

It would be easy to multiply these examples to almost any extent, although they are not so frequent in Great Britain. It is related in Hasted’s History of Kent, that about Easter, 1666, in the parish of Stanstead, which is a considerable distance from the sea, and a place where there are no fishponds, and rather a scarcity of water, a pasture field was scattered all over with small fish, supposed to have been rained down during a thunder-storm. Several of these fish were sold publicly at Maidstone and Dartford. In the year 1830, the inhabitants of the island of Ula, in Argyleshire, after a day of very hard rain, which occurred on the 9th March, were surprised to find numbers of small herrings strewed over the fields, perfectly fresh and some of them alive. Some years ago, during a strong gale, herrings and other fish were carried from the Frith of Forth so far as Loch-Leven.

In some countries rats migrate in vast numbers from the high to the low countries; and it is recorded in the history of Norway, that a shower of these, transported by the wind, fell in an adjacent valley.

Several notices have, from time to time, been brought before the French Academy, of showers of frogs having fallen in different parts of France. Professor Pontus, of Cahors, states, that in August, 1804, while distant three leagues from Toulouse, the sky being clear, suddenly a very thick cloud covered the horizon, and thunder and lightning came on. The cloud burst over the road about sixty toises (383 feet) from the place where M. Pontus was. Two gentlemen, returning from Toulouse, were surprised by being exposed not only to a storm, but to a shower of frogs. Pontus states that he saw the young frogs on their cloaks. When the diligence in which he was travelling, arrived at the place where the storm burst, the road, and the fields alongside of it, were observed full of frogs, in three or four layers placed one above the other. The feet of the horses and the wheels of the carriage killed thousands. The diligence travelled for a quarter of an hour, at least, along this living road, the horses being at a trot.

In the “Journal de St. Petersburg,” is given an account of the fall of a shower of insects during a snow-storm in Russia. “On the 17th October, 1827, there fell in the district of Rjev, in the government of Tver, a heavy shower of snow, in the space of about ten versts (nearly seven English miles), which contained the village of Pakroff and its environs. It was accompanied in its fall by a prodigious quantity of worms of a black colour, ringed, and in length about an inch and a quarter. The head of these insects was flat and shining, furnished with antennæ, and the hair in the form of whiskers; while the body, from the head to about one-third of their length, resembled a band of black velvet. They had on each side three feet, by means of which they appeared to crawl very fast upon the snow, and assembled in groups about the plants and the holes in trees and buildings. Several having been exposed to the air in a vessel filled with snow, lived there till the 26th October; although, in that interval, the thermometer had fallen to eight degrees below zero. Some others which had been frozen continued alive equally long; for they were not found exactly encrusted with the ice, but they had formed round their bodies a space similar to the hollow of a tree. When they were plunged into water they swam about as if they had received no injury; but those which were carried into a warm place perished in a few minutes.”

All these remarkable showers may be accounted for, when we consider the mighty power of the wind; especially that form of it which is popularly called the whirlwind. It is now pretty well ascertained, that in all, or most of the great storms which agitate the atmosphere, the wind has a circular or rotatory movement; and the same is probably the case in many of the lesser storms, in which the air is whirled upwards in a spiral curve with great velocity, carrying up any small bodies which may come within the circuit. When such a storm happens at sea, the water-spout is produced. In the deserts of Arabia, pillars of sand are formed; and, in other places various light bodies are caught up; fishponds have been entirely emptied in an instant, and the moving column, whether of water, sand, or air, travels with the wind with great swiftness. When, however, the storm has subsided, the various substances thus caught up and sustained in the air, are deposited at great distances from the place where they were first found, and thus produce these remarkable showers. In some cases, however, the direct force of the wind has actually blown small fish out of the water, and conveyed them several miles inland.

Showers of nutritious substances have been recorded on good authority. We do not here refer to the manna which fell in such abundance about the Hebrew camp, for that was a miracle specially wrought by the Almighty for the preservation of his chosen people; but, it may be noticed here, that in Arabia, a substance, called “manna,” is found in great abundance on the leaves of many trees and herbs, and may be gathered and removed by the wind to a distance. A shower of this kind occurred in 1824. In 1828, a substance was exhibited at the French Academy, which fell in the plains of Persia. It was eaten, and afforded nourishment to cattle, and many other animals; and, on examination, proved to be a vegetable,—the Lichen esculentus,—which had been conveyed thither by the winds.

In the Minutes of the proceedings of the Royal Society, 26th June, 1661, we find the following curious narration:—

“Col. Tuke brought, in writing, the following brief account of the supposed rain of wheat, which was registered:—

“On the 30th of May, 1661, Mr. Henry Puckering, son to Sir Henry Puckering, of Warwick, brought some papers of seeds, resembling wheat, to the king, with a letter written by Mr. William Halyburton, dated the 27th May, from Warwick; out of which letter I have made this extract:

“‘Instead of news I send you some papers of wonders. On Saturday last, it was rumoured in this town, that it rained wheat at Tuchbrooke, a village about two miles from Warwick. Whereupon some of the inhabitants of this town went thither; where they saw great quantities on the way, in the fields, and on the leads of the church, castle, and priory, and upon the hearths of the chimneys in the chambers. And Arthur Mason, coming out of Shropshire, reports, that it hath rained the like in many places of that county. God make us thankful for this miraculous blessing, &.’”

“I brought some papers of these seeds, with this letter, to the Society of Gresham College; who would not enter into any consideration of it, till they were better informed of the matter of fact. Hereupon, I entreated Mr. Henry Puckering to write to the bailiff of the town of Warwick, to the ministers and physicians, to send us an account of the matter of fact, and their opinions of it. In the bailiff’s letter, dated the 3rd of June, I find this report verified; affirming that himself, with the inhabitants of the town, were in a great astonishment at this wonder. But, before the next day of our meeting, I sent for some ivy-berries, and brought them to Gresham College with some of these seeds resembling wheat; and taking off the outward pulp of the ivy-berries, we found in each of the berries four seeds; which were generally concluded by the Society to be the same with those that were supposed and believed by the common people to have been wheat that had been rained; and, that they were brought to those places, where they were found, by starlings; who, of all the birds that we know, do assemble in the greatest numbers; and do, at this time of the year, feed upon these berries; and digesting the outward pulp, they render these seeds by casting, as hawks do feathers and bones.”

The remarkable showers already noticed, have excited much interest and inquiry among learned men, and many superstitious fears among the ignorant; but, there is another description of shower which affords a singular instance of popular observation, being greatly in advance of scientific knowledge. We allude to the showers of stones, called “aërolites,” (from two Greek words, signifying the atmosphere, and a stone); they are also called Meteorolites, or Meteoric stones.

Writers in all ages have mentioned instances of stony bodies having been seen to fall from the sky. The Chinese and Japanese carefully note down the most striking and remarkable phenomena of nature, believing them to have some connexion with public affairs; and the chronicles of these people are said to contain many notices of the fall of stony bodies from the sky. Until within the last fifty years, however, these accounts have been treated in Europe as idle superstitions; scientific men denying even the probability of such an occurrence. The first scientific man who was bold enough to support the popular opinion, that stones actually do fall from the sky, was Chladni, a German philosopher, who published a pamphlet on the subject in 1794. This did not excite much attention, until, two years afterwards, a stone weighing fifty-six pounds was exhibited in London, which was said to have fallen in Yorkshire in the December of the preceding year; but, although the fact was attested by several respectable persons, the possibility of such an occurrence was still doubted. It was remarked, however, by Sir Joseph Banks, that this stone was very similar in appearance to one which had been sent to him from Italy, with an account of its having fallen from the clouds. In the year 1799, a number of stones were received by the Royal Society, from Benares, in the East Indies, which were also said to have fallen from the atmosphere, with a minute account of the circumstances attending the fall, which will be presently noticed; and, as these stones appeared to be precisely similar to the Yorkshire stone already noticed, attention was fairly drawn to the subject. In 1802, Mr. Howard published an analysis of a variety of these stones collected from different places; and his researches led to the important conclusion, that they are all composed of the same substances, and in nearly the same proportions. In 1803, a notice was received at Paris, of a shower of stones at L’Aigle in Normandy; and the Institute of France deputed M. Biot, a well-known and excellent natural philosopher, to examine, on the spot, all the circumstances attending this remarkable event. His account will be noticed presently; but it may here be stated, that the stones he collected, on being analysed, gave results similar to those obtained by Mr. Howard.

The circumstances attending the fall of stones at Krakhut, a village about fourteen miles from the city of Benares, are briefly as follow:—On the 19th December, 1798, a very luminous meteor was observed in the heavens, about eight o’clock in the evening, in the form of a large ball of fire; it was accompanied by a loud noise, resembling that of thunder, which was immediately followed by the sound of the fall of heavy bodies. On examining the ground, it was observed to have been newly torn up in many places; and in these were found stones of a peculiar appearance, most of which had buried themselves to the depth of six inches. At the time the meteor appeared, the sky was perfectly serene, not the smallest vestige of a cloud had been seen since the 11th of the month; nor were any observed for many days after. It was seen in the western part of the hemisphere, and was visible only a short time. The light from it was so great, as to cast a strong shadow from the bars of a window upon a dark carpet. Mr. Davis, the judge and magistrate of the district, affirmed, that in brilliancy it equalled the brightest moonlight. Both he and Mr. Erskine were induced to send persons in whom they could confide to the spot where this shower of stones is reported to have taken place, and thus obtained additional evidence of the phenomena, together with several of the stones which had penetrated about six inches into fields recently watered. Mr. Maclane, a gentleman who resided near Krakhut, presented Mr. Howard with a portion of a stone which had been brought to him the morning after its fall by the person who was on duty at his house, and through the roof of whose hut it had passed, and buried itself several inches in the floor, which was of consolidated earth. Before it was broken it must have weighed upwards of two pounds.

M. Biot’s summary of the evidence collected by him respecting the great shower of stones which fell at Aigle, in Normandy, is as follows:—

“On Tuesday, 26th April, 1803, about one o’clock, p.m., the weather being serene, there was observed from Caen, Pont d’Audemer, and the environs of Alençon, Falaise, and Verneuil, a fiery globe, of a very brilliant splendour, and which moved in the atmosphere with great rapidity. Some moments after, there was heard at Aigle, and in the environs of that town, in the extent of more than thirty leagues in every direction, a violent explosion, which lasted five or six minutes. At first there were three or four reports like those of a cannon, followed by a kind of discharge which resembled the firing of musketry; after which, there was heard a dreadful rumbling, like the beating of a drum. The air was calm and the sky serene, except a few clouds, such as are frequently observed. This noise proceeded from a small cloud which had a rectangular form; the largest side being in a direction from east to west. It appeared motionless all the time that the phenomenon lasted; but the vapours of which it was composed, were projected momentarily from different sides, by the effect of successive explosions. This cloud was about half a league to the north-north-west of the town of Aigle. It was at a great elevation in the atmosphere; for, the inhabitants of two hamlets, a league distant from each other, saw it at the same time above their heads. In the whole canton over which this cloud was suspended, there was a hissing noise, like that of a stone discharged from a sling; and a great many mineral masses, exactly similar to those distinguished by the name of ‘meteor-stones,’ were seen to fall. The district in which these masses were projected, forms an elliptical extent of about two leagues and a half in length, and nearly one in breadth, the greatest dimension being in a direction from south-east to north-west; forming a declination of about 22 degrees. This direction, which the meteor must have followed, is exactly that of the magnetic meridian, which is a remarkable result. The greatest of these stones fell at the south-eastern extremity of the large axis of the ellipse, the middle-sized in the centre, and the smaller at the other extremity. Hence it appears, that the largest fell first, as might naturally be supposed. The largest of all those that fell, weighs seventeen pounds and a half. The smallest which I have seen, weighs about two gros, (a thousandth part of the last.) The number of all those which fell, is certainly above two or three thousand.”

Meteoric stones have been known to commit great injury in their fall. In July, 1790, a very bright fire-ball, luminous as the sun, of the size of an ordinary balloon, appeared near Bourdeaux, which, after filling the inhabitants with alarm, burst, and disappeared. A few days after, some peasants brought stones into the town, which they said had fallen from the meteor; but, the philosophers to whom they offered them laughed at their statements. One of these stones, fifteen inches in diameter, broke through the roof of a cottage, and killed a herdsman and a bullock. In 1810, a great stone fell at Shahabad, in India. It burnt a village, and killed several people.

The fall of meteoric stones is more frequent than would be supposed. Chaldni has compiled a Catalogue of all recorded instances from the earliest times. Of these, twenty-seven are previous to the Christian era; thirty-five from the beginning of the first to the end of the fourteenth century; eighty-nine from the beginning of the fifteenth to the beginning of the present century; from which time, since the attention of scientific men has been directed to the subject, above sixty cases have been recorded. These are, doubtless, but a small proportion of the whole amount of meteoric showers which have fallen, when the small extent of surface occupied by those capable of recording the event is compared with the wide expanse of the ocean, the vast uninhabited deserts, mountains, and forests, and the countries occupied by savage nations.

Meteoric stones have generally a broken, irregular surface, coated with a thin black crust, like varnish. When broken, they appear to have been made up of a number of small spherical bodies of a grey colour, imbedded in a gritty substance, and often interspersed with yellow spots. A considerable proportion of iron is found in all of them, partly in a malleable state, partly in that of an oxide, and always in combination with a rather scarce metal called nickel; [181] the earths silica, and magnesia, and sulphur, form the other chief ingredients; but, the earths alumina and lime, the metals manganese, chrome, and cobalt, together with carbon, soda, and water, have also been found in small quantities, but not in the same specimens. No substance with which chemists were previously unacquainted, has ever been found in them; but no combination, similar to that in meteoric stones, has ever been met with in geological formations, or among the products of any volcano. They are sometimes very friable, sometimes very hard; and some that are friable when they first fall, become hard afterwards. When taken up soon after their fall they are extremely hot. They vary in weight from two drams to several hundred pounds. Meteoric stones have fallen in all climates, in every part of the earth, at all seasons, in the night and in the day.

The meteoric stones already noticed, are not the only metallic bodies which are supposed to fall from the sky. In many parts of the earth masses of malleable iron, often of vast size, have been found. An immense mass seen by Pallas, in Siberia, was discovered at a great height on a mountain of slate, near the river Jenesei. The Tartars held it in great veneration, as having fallen from heaven. It was removed in the year 1749, to the town of Krasnojarsk, by the inspector of iron mines. The mass, which weighed about 1,400 pounds, was irregular in form, and cellular, like a sponge. The iron was tough and malleable, and was found to contain nickel, silica, magnesia, sulphur, and chrome. Another enormous mass of meteoric iron was found in South America, about the year 1788. It lay in a vast plain, half sunk in the ground, and was supposed, from its size and the known weight of iron, to contain upwards of thirteen tons. Specimens of this mass are now in the British Museum, and have been found to contain 90 per cent. of iron and 10 of nickel. Many other masses of iron might be mentioned, which, from the places in which they are found, and from their composition, leave no doubt as to their being of meteoric origin. The only instance, on record, of iron having been actually seen to fall from the atmosphere, is that which took place at Agram in Croatia, on the 26th May, 1751. About six o’clock in the evening, the sky being quite clear, a ball of fire was seen, which shot along, with a hollow noise, from west to east, and, after a loud explosion accompanied by a great smoke, two masses of iron fell from it in the form of chains welded together.

It is, perhaps, impossible, in the present state of our knowledge, to account for the origin of these remarkable bodies. Some have supposed them to have been shot out from volcanoes belonging to our earth; but this theory is opposed by the fact that no substance, resembling aërolites, has ever been found in or near any volcano; and they fall from a height to which no volcano can be supposed to have projected them, and still less to have given them the horizontal direction in which they usually move. Another supposition is, that these masses are formed in the atmosphere; but it is almost ridiculous to imagine a body, weighing many tons, to be produced by any chemical or electrical forces in the upper regions of the air. A third explanation is, that they are bodies thrown out by the volcanoes, which are known to exist in the moon, with such force as to bring them within the sphere of the earth’s attraction. This notion was supported by the celebrated astronomer and mathematician La Place. He calculated that a body projected from the moon with the velocity of 7771 feet in the first second, would reach our earth in about two days and a half. But other astronomers are of opinion, that the known velocity of some meteors is too great to admit of the possibility of their having come from the moon. The theory which agrees best with known facts and the laws of nature, is that proposed by Chladni, namely, that the meteors are bodies moving in space, either masses of matter as originally created, or fragments separated from a larger mass of a similar nature. This view has also been supported by Sir Humphrey Davy, who says, “The luminous appearances of shooting-stars and meteors cannot be owing to any inflammation of elastic fluids, but must depend upon the ignition of solid bodies. Dr. Halley calculated the height of a meteor at ninety miles; and the great American meteor, which threw down showers of stones, was estimated at seventeen miles high. The velocity of motion of these bodies must, in all cases, be immensely great, and the heat produced by the compression of the most rarefied air from the velocity of motion, must be, probably, sufficient to ignite the mass; and all the phenomena may be explained, if falling stars be supposed to be small bodies moving round the earth in very eccentric orbits, which become ignited only when they pass with immense velocity through the upper region of the atmosphere; and if the meteoric bodies which throw down stones with explosions, be supposed to be similar bodies which contain either combustible or elastic matter.”

This chapter ought not to be concluded without a short notice of that remarkable rain known to geologists as “fossil rain.” In the new red-sandstone of the Storeton quarries, impressions of the foot-prints of ancient animals have been discovered; and in examining some of the slabs of stone extracted at the depth of above thirty feet, Mr. Cunningham observed “that their under surface was thickly covered with minute hemispherical projections, or casts in relief of circular pits, in the immediately subjacent layers of clay. The origin of these marks, he is of opinion, must be ascribed to showers of rain which fell upon an argillaceous beach exposed by the retiring tide, and their preservation to the filling up of the indentations by sand. On the same slabs are impressions of the feet of small reptiles, which appear to have passed over the clay previously to the shower, since the foot-marks are also indented with circular pits, but to a less degree; and the difference Mr. Cunningham explains by the pressure of the animal having rendered these portions less easily acted upon.” The preservation of these marks has been explained by supposing dry sand, drifted by the wind, to have swept over and filled up the footprints, rain-pits, and hollows of every kind, which the soft argillaceous surface had received.

The frontispiece to the present chapter (p. 156), represents a slab of sandstone containing impressions of the foot of a bird and of rain drops. This slab is from a sandstone basin near Turner’s Falls, a fine cataract of the Connecticut river in the State of Massachusetts, and is described by Dr. Deane in a recent number of the American Journal of Science. “It is rare,” says that gentleman, to “find a stratum containing these footprints exactly as they were made by the animal, without having suffered change. They are usually more or less disturbed or obliterated by the too soft nature of the mud, the coarseness of the materials, and by many other circumstances which we may easily see would deface them, so that although the general form of the foot may be apparent, the minute traces of its appendages are almost invariably lost. In general, except in thick-toed species, we cannot discover the distinct evidences of the structure of the toes, each toe appearing to be formed of a single joint, and seldom terminated by a claw. But, a few specimens hitherto discovered at this locality completely developed the true characters of the foot, its ranks of joints, its claws and integuments. So far as I have seen, the faultless impressions are upon shales of the finest texture with a smooth glossy surface, such as would retain the beautiful impressions of rain drops. This kind of surface containing footmarks is exceedingly rare: I have seen but few detached examples; recently it has been my good fortune to recover a stratum, containing in all more than one hundred most beautiful impressions of the feet of four or five varieties of birds, the entire surface being also pitted by a shower of fossil rain-drops. The slabs are perfectly smooth on the inferior surface, and are about two inches in thickness.

“The impression of a medallion is not more sharp and clear than are most of these imprints, and it may be proper to observe, that this remarkable preservation may be ascribed to the circumstance, that the entire surface of the stratum was incrusted with a layer of micaceous sandstone, adhering so firmly that it would not cleave off, thereby requiring the laborious and skilful application of the chisel. The appearance of this shining layer which is of a gray colour, while the fossil slab is a dark red, seems to carry the probability that it was washed or blown over the latter while in a state of loose sand, thus filling up the foot-prints and rain-drops, and preserving them unchanged until the present day—unchanged in the smallest particular, so far as relates merely to configuration, nothing being obliterated; the precise form of the nails, or claws, and joints, and in the deep impressions of the heel bone, being exquisitely preserved.”

The small slab figured at p. 156 is described as being an incomparable specimen. “For purity of impression it is unsurpassed, and the living reality of the rain-drops, the beautiful colour of the stone, its sound texture and lightness, renders it a fit member for any collection of organic remains.”

Mandan rain-makers