| ( | 7912·40 ———— 5·49 |
) | 1 ———— 1441 |
| ( | 1441 —— 12 |
= |
) |
| ( | 1441 —— 90 |
= |
) |
“If we would construct a correct model of our earth, with its seas, continents, and mountains, on a globe 16 inches in diameter, the whole of the land, with the exception of a few prominent points and ridges, must be comprised on it within the thickness of thin writing paper; and the highest hills would be represented by the smallest visible grains of sand.”[17]
Astronomers have measured the distances and weighed the masses of the planets, yet the height of the atmosphere and the depths of the ocean are unsolved problems. The bottom of “blue water” is almost as unknown to us as the interior of the earth. It is a common opinion that the greatest depths of the sea are about equal to the greatest heights of the mountains. Attempts have been repeatedly made to sound out its depths, but no reliance can be placed on any reports of soundings beyond 8000 or 10,000 feet. One ran out his sounding-line 34,000 feet, and did not touch bottom; another 39,000 feet with the same result; one reported bottom at 49,000 feet, another at 50,000 feet. But there are no such depths. There are currents and counter-currents in the ocean, as in the air, which operate upon the bight of the sounding-line, and cause it to run out after the weight has reached the bottom, so that the shock cannot be felt.
The oceanic circulation is as complete as that of the atmosphere, and is possibly subject to, or governed by, the same laws; and there appears to be a law of descent through “blue water,” the same as there is a law of ascent through “blue air.” The one increases in density downwards as the other decreases in density upwards; and the development of this law proves that the sea is not so deep as reports made it.
There is a set of currents in the sea by which its waters are conveyed from place to place through regular and certain channels, traversing from one ocean to the other with the regularity of the machinery of a watch. The chief motive power of marine currents is caused by heat. But an active agency in the system of circulation is derived from the salts of the sea-water, by winds, marine plants, and animals. These give the ocean great dynamical force.
| ( | 7912·40 ———— 10·23 |
) | 1 —— 773 |
The specific gravity of Sea-water varies of course with the proportion of salts and the degree of heat it receives from the sun, or by the intermixture of currents of various temperatures; but in our own latitudes it is about 1·028—that is, a given volume of pure distilled water weighing 1000 grains, the same volume of sea-water weighs 1028 grains. Many useful substances are daily extracted from the sea for the use of man, among which we may mention pure water for the use of ships, salt, iodine, bromine, &c. Many attempts have been made to purity sea-water in order to render it potable, not only for supplying ships, but for the use of maritime towns and villages, where pump-water is often brackish, and where the inhabitants are frequently obliged to have recourse to rain-water. Now, when sea-water is submitted to congelation, it abandons its salt almost completely—a fact which appears to have been discovered many years ago by Chevalier Lorgna, who found that a mixture of three parts of pounded ice and two parts of common salt produced a cold of about 4° below the zero of a Fahrenheit thermometer, and that such a mixture caused sea-water to freeze rapidly. A mixture of various chemical salts in proper proportions produces a similar degree of cold. Lately, the cold produced by the evaporation of ether has been proposed for the same purpose. The purification is complete if the ice thus formed be melted and frozen again. In the Polar regions the ice formed from salt-water is more or less opaque, except it be in very small pieces, when it transmits light of a bluish green shade. When melted, it produces sometimes perfectly fresh water, and at other times water slightly brackish. The fresh-water ice resulting from rain or melted snow, as seen floating in the Arctic seas, is distinguished from the salt-water ice by its black appearance, especially when in small pieces, and by its transparency when removed from the water into the air. Its transparency is so great, when compared with sea-ice, that Dr. Scoresby used to amuse his sailors by cutting large lenses out of this fresh-water ice, and using them as burning-glasses to light the men’s pipes. Their astonishment was increased by observing that the ice did not melt, while the solar rays emerging from it were so hot that the hand could not be kept more than a second or two at the focus.—Macmillan’s Magazine.
On the surface of the globe there is nowhere to be found so inhospitable a desert as the “wide blue sea.” At any distance from land there is nothing in it for man to eat, nothing in it that he can drink. His tiny foot no sooner rests upon it, than he sinks into his grave: it grows neither flowers nor fruits; it offers monotony to the mind, restless motion to the body; and when, besides all this, one reflects that it is to the most fickle of the elements, the wind, that vessels of all sizes are to supplicate for assistance in sailing in every direction to their various destinations, it would almost seem that the ocean was divested of its charms, and armed with storms, to prevent our being persuaded to enter its dominions.
But though the situation of a vessel in a heavy gale of wind appears indescribably terrific, yet, practically speaking, its security is so great, that it is truly said that ships seldom or never founder in deep water, except from accident or inattention. How ships manage to get across that still region, that ideal line, which separates the opposite trade-winds from each hemisphere; how a small box of men manages, unlabelled, to be buffeted for months up one side of a wave and down another; how they ever get out of the abysses into which they sink; and how, after such pitching and tossing, they reach in safety the very harbour in their native country from which they originally departed—can and ought only to be accounted for, by acknowledging how truly it has been written, that “the Spirit of God moves upon the face of the waters.”
It is not, therefore, from the ocean itself that man has so much to fear: the earth and the water each afford to man a life of considerable security, yet there exists between these two elements an everlasting war, into which no passing vessel can enter with impunity; for of all the terrors of this world, there is surely no one greater than that of being on a lee-shore in a gale of wind, and in shallow water. On this account it is natural enough that the fear of land is as strong in the sailor’s heart as is his attachment to it; and when, homeward bound, he day after day approaches his own latitude, his love and his fears of his native shores increase as the distance between them diminishes. Two fates, the most opposite in their extremes, are shortly to await him. The sailor-boy fancifully pictures to himself that in a few short hours he will be once again nestling in his mother’s arms. The able seaman better knows that it may be decreed for him, as it has been for thousands, that in gaining his point he shall lose its object—that England, with all its virtue, may fade before his eyes, and,
Nor can it be regarded as improbable that in the beds of the present seas the edifices and works of nations, whose history is altogether unknown to existing generations, are embedded and preserved:
These limitations are great. Ages before the existence of scientific astronomy, the question was put to the patriarch Job, “Canst thou bind the sweet influences of Pleiades, or loose the bands of Orion; canst thou bring forth Mazzaroth in his season? or canst thou guide Arcturus with his sons?” And when Job in his heart, if not with his lips, answered the Almighty, No, he answered for all his successors as well as for himself. Astronomical problems accumulate unsolved on our hands, because we cannot, as mechanicians, chemists, or physiologists, experiment upon the stars. Are they built of the same materials as our planet? Are they inhabited? Are Saturn’s rings solid or liquid? Has the moon an atmosphere? Are the atmospheres of the planets like ours? Are the light and heat of the sun begotten of combustion? and what is the fuel which feeds his unquenchable fires? These are but a few of the questions which we ask, and variously answer, but leave in reality unanswered, after all. A war of words regarding the revolution of the moon round her axis may go on to the end of time, because we cannot throw our satellite out of gearing, or bring her to a momentary stand-still; and the problem of the habitability of the stars awaits in vain an experimentum crucis.
The astronomer, accordingly, must be content to be the chronicler of a spectacle, in which, except as an on-looker, he takes no part. Like the sailor at the mast-head in his solitary night-watch, he must see, as he sails through space in his small earthly bark, that nothing escapes his view within the vast visible firmament. But he stands, as it were, with folded arms, occupied solely in wistfully gazing over the illimitable ocean, where the nearest vessel, like his own, is far beyond summons or signal, and the greatest appears but as a speck on the distant horizon. His course lies out of the track of every other vessel; and year after year he repeats the same voyage, without ever practically altering his relation to the innumerable fleets which navigate those seas.—Professor George Wilson, on the Physical Sciences, &c.
Mr. Hind, the astronomer, in a communication to the Times, September 17, 1863, observes: “It may occasion surprise to many who are accustomed to read of the precision now attained in the science and practice of Astronomy, when it is stated that there are strong grounds for supposing the generally received value of that great unit of celestial measures—the mean Distance of the Earth from the Sun—to be materially in error; and that, in fact, we are nearer to the central luminary by some 4,000,000 miles than for many years past has been commonly believed. The results of various researches during the last ten years appear, however, to point to the same conclusion.”
Mr. Hind then proceeds to describe the actual state of our knowledge respecting it, extending through two entire columns of the above Journal. We have only space for the results:
“To recapitulate briefly: a diminution in the measure of the sun’s distance now adopted is implied by—1st, the theory of the moon, as regards the parallactic equation, agreeably to the researches of Professor Hansen and the Astronomer Royal; 2nd, the lunar equation in the theory of the earth, newly investigated by M. Le Verrier; 3rd, the excess in the motion of the node of the orbit of Venus beyond what can be due to the received values of the planetary masses; 4th, the similar excess in the motion of the perihelion of Mars, also detected within the past few years by the same mathematician; 5th, the experiments of M. Foucault on the velocity of light; and 6th, the results of observations of Mars when near the earth about the opposition of 1862.
“Subjoined are a few of the numerical changes which will follow upon the substitution of M. Le Verrier’s solar parallax (8´´·95) for that of Professor Encke, on which reliance has so long been placed. The earth’s mean distance from the sun becomes 91,328,600 miles, being a reduction of 4,036,000. The circumference of her orbit, 599,194,000 miles, being a diminution of 25,360,000. Her mean hourly velocity, 65,460 miles. The diameter of the sun 850,100 miles, which is smaller by nearly 38,000. The distances, velocities, and dimensions of all the members of the planetary system of course require similar corrections if we wish to express them in miles; in the case of Neptune, the mean distance is diminished by 30 times the amount of correction to that of the earth, or about 122,000,000 miles. The velocity of light is decreased by nearly 8000 miles per second, and becomes 183,470 if based upon astronomical data alone. These numbers will illustrate the great importance that attaches to a precise knowledge of the sun’s parallax, in our appreciation of the various distances and dimensions in the solar system.
“The evidence which has been adduced since the publication of M. Le Verrier’s investigations, would rather induce us to adopt a diminished measure of the earth’s distance from the sun, as the most probable solution of the difficulty.
“M. Léon Foucault, of Paris, has succeeded in measuring the absolute velocity of light by means of the ‘turning mirror’—an experimental determination of no little interest and significance. He concludes that it cannot differ much from 298,000,000 of French metres per second, or 185,170 English miles, which is a notable diminution upon the velocity previously derived from astronomical data alone. The time which light requires to travel from the sun to the earth is known with great precision; at the mean distance of the latter it is rather less than 8´ 18´´, and if this number be combined with M. Foucault’s measure of the velocity, it will be evident that the received distance is too great by about one-thirtieth part—that light, in fact, has not so far to travel before it reaches the earth as generally supposed. The corresponding solar parallax is 8´ 86´´, which approaches much nearer to M. Le Verrier’s theoretical value than to the one depending on the transits of 1761 and 1769. So curious a corroboration of the former deserves especial remark.”
Mr. Glaisher, in his Report of Scientific Balloon ascents made by him and Mr. Coxwell, in 1863, remarks that the Colour of the Sky in 1862 was of a deeper blue generally than in 1863. On the 31st of March the sky was of a deep Prussian blue, and on the 18th of April it was of a faint blue only, exhibiting another great contrast to the appearance of last year. Sir Isaac Newton considers this colour as a “blue of the first order, though very faint and little, for all vapours, when they begin to condense and coalesce into small parcels, become first of that bigness, whereby such an azure must be reflected.” Professor Clausius considers the vapours to be vesicles or bladders, and ascribes the blue colour of the first order to reflection from the thin pellicle of water. In reference to these opinions the following facts are important:—1. The azure colour of the sky, though resembling the blue of the first order when the sky is viewed from the earth’s surface, becomes, as observed by Mr. Glaisher in his balloon ascents, an exceedingly deep Prussian blue, as we ascend to the height of five or six miles, which is a deep blue of the second or third order. 2. The maximum polarizing angle of the atmosphere being 45 deg. is that of air, and not that of water, which is 55 deg. 3. At the greatest height to which Mr. Glaisher ascended—namely, at the height of five, six, and seven miles, where the blue is the brightest—“the air is almost deprived of moisture.”
Hence it follows that the exceedingly deep Prussian blue cannot be produced by vesicles of water, but must be caused by reflection from the molecules of air, whose polarizing angle is 45 deg. The faint blue which the sky exhibits at the earth’s surface is therefore not the blue of the first order, and is merely the blue of the second or third order, rendered paler by the light reflected from the aqueous vapour in the lower regions of the atmosphere.
Mr. Glaisher speaks of the curious changes in colour that he and Mr. Coxwell experienced in ascending, and remarked that they could now easily go a mile higher without turning quite so blue as before. In one descent they very nearly got into the sea, and only escaped that fate by coming down at the rate of four miles in two minutes.
It is a strange thing how little in general people know about the Sky. It is the part of creation in which Nature has done more for the sake of pleasing man, more for the sole and evident purpose of talking to him and teaching him, than in any other of her works, and it is just the part in which we least attend to her. There are not many of her other works in which some more material or essential purpose than the mere pleasing of man is not answered by every part of their organization; but every essential purpose of the sky might, as far as we know, be answered, if once in three days, or thereabouts, a great black ugly rain-cloud were broken up over the blue, and everything well watered, and so all left blue again till next time, with perhaps a film of morning and evening mist for dew. But, instead of this, there is not a moment of any day of our lives when Nature is not producing scene after scene, picture after picture, glory after glory, and working still upon such exquisite and constant principles of the most perfect beauty, that it is quite certain it is all done for us, and intended for our perpetual pleasure.—John Ruskin.
Professor Owen has remarked the importance of the influences of very high distances on the human frame, which is adapted of course to a very different medium. The fact which Mr. Glaisher mentions as to his feeling a greater power of resisting the influence of very high temperatures is interesting in physiology, and in relation to the series of facts with which we are acquainted. We know that our lungs adapt themselves to atmospheres of different degrees of gravity, so that there are people who live habitually on high mountains, and feel no such difficulty in breathing as is felt at once when the inhabitant of a plain or low country comes up to these elevations. Now that depends upon the greater proportion of the minute cells of the lungs which are open and receive an attenuated atmosphere, in proportion to the minute cells that are occupied by a quantity of mucus. Those on the plain do not make so large a use of their breathing apparatus as those who live at great altitudes. Hence more cells, occupied by mucus, will be taken up, and opened to free course and play; and Professor Owen has no doubt that is the solution of the interesting fact mentioned by Mr. Glaisher. Physiologists are all agreed that one condition of longevity is the capacity of the chest; and therefore it is hoped the increased breathing capacity acquired by Mr. Glaisher and Mr. Coxwell will tend to the prolongation of their lives.
The establishment of a Meteorological Department by the Board of Trade is understood to have originated with the late Prince Consort, who suggested that the more methodical observation of the phenomena of the Weather might be rendered conducive to the saving of many valuable lives. The plan had worked to February, 1861, when the Secretary of the Board of Trade wrote to the Royal Society concerning the new features which the operations of the Meteorological Department had assumed; and expressing an anxiety to know whether the science of meteorology was now in such a state as to admit of a permanent reliable system of storm-signals and daily weather forecasts; also, whether the progress and useful application of meteorological science would be more efficiently promoted by devoting the money voted by Parliament to the original objects contemplated—viz., the collection, tabulation, and discussion of meteorological phenomena, or by devoting it to the system of telegraphy and weather forecasts. The Secretary of the Royal Society, after the lapse of a month, replied, on behalf of the President and Council, to the effect that they were assured by Admiral Fitzroy that the original objects for which the Meteorological Department was formed were still kept in view. “In the forewarnings of storms,” adds Dr. Sharpey, “much must as yet undoubtedly be viewed as in a great measure tentative; but there is one class of cases on which such premonitory information is entitled to be regarded as resting on more assured scientific relations. Admiral Fitzroy considers that he has satisfactorily established the occasional occurrence of storms of a cyclonic character, of very limited diameter, not much exceeding perhaps that of the British islands themselves, and originating in their vicinity. The practice of forewarning is specially suited to such storms. They are characterized by great violence, and by frequent and rapid changes in the direction of the wind. The key to their comprehension is supplied by the telegraphic reports, which convey to the central office a knowledge of the various simultaneous directions of the wind in different localities; and, when once comprehended, they are particularly suited for forewarning, inasmuch as, in its general course, the advance of the cyclone is steady in direction and moderate in rate.
“In connexion with this subject the President and Council revert with satisfaction to a reply by Sir John Herschel to the Royal Commission on Lights, Buoys, and Beacons, that ‘the most important meteorological information which could be telegraphed would be information first received by telegraph of a cyclone actually in progress at a great distance, and working its way towards the locality. There is no doubt that the progress of a cyclone may be telegraphed, and might secure many a ship from danger by forewarning.’ It is obvious that this remark, which refers to the approach of a distant cyclone, is equally applicable to cyclones originating in or near our islands, the existence of which has been made known by the system of telegraphy which Admiral Fitzroy has established.
“With respect to the ‘forecasts of the state of the weather,’ which are published in the newspapers, the President and Council learn from Admiral Fitzroy that they really occasion no cost to Government, and scarcely fall, therefore, within the questions submitted for reply; moreover, the President and Council have no data whereon to rest a conclusion in regard to the degree of reliance to which these last-named forecasts may be entitled.”
A few of the more marked Signs of Weather—useful alike to seaman, farmer, and gardener, are the following:
Whether clear or cloudy—a rosy sky at sunset presages fine weather:—a red sky in the morning bad weather, or much wind (perhaps rain):—a grey sky in the morning, fine weather:—a high dawn, wind:—a low dawn, fair weather.
Soft-looking or delicate clouds foretell fine weather, with moderate or light breezes:—hard edged, oily-looking clouds,—wind. A dark, gloomy, blue sky is windy;—but a light bright blue sky indicates fine weather. Generally, the softer clouds look, the less wind (but perhaps more rain) may be expected;—and the harder, more “greasy,” rolled, tufted, or ragged,—the stronger the coming wind will prove. Also—a bright yellow sky at sunset presages wind; a pale yellow, wet:—and thus by the prevalence of red, yellow, or grey tints, the coming weather may be foretold very nearly:—indeed, if aided by instruments, almost exactly.
Small inky-looking clouds foretell rain:—light scud clouds driving across heavy masses show wind and rain, but if alone, may indicate wind only.
High upper clouds crossing the sun, moon, or stars, in a direction different from that of the lower clouds, or the wind then felt below, foretell a change of wind.
After fine clear weather, the first signs in the sky of a coming change are usually light streaks, curls, wisps, or mottled patches of white distant clouds, which increase and are followed by an overcasting of murky vapour that grows into cloudiness. This appearance, more or less oily or watery, as wind or rain will prevail, is an infallible sign.
Usually the higher and more distant such clouds seem to be, the more gradual but general the coming change of weather will prove.
Light, delicate, quiet tints or colours, with soft, undefined forms of clouds, indicate and accompany fine weather; but gaudy, or unusual hues, with hard, definitely outlined clouds, foretell rain and probably strong wind. Misty clouds forming, or hanging on heights, show wind and rain coming—if they remain, increase, or descend. If they rise or disperse, the weather will improve or become fine.
When sea birds fly out early and far to seaward, moderate wind and fair weather may be expected.
When they hang about the land, or over it, sometimes flying inland, expect a strong wind with stormy weather. As many creatures besides birds are affected by the approach of rain or wind, such indications should not be slighted by an observer who wishes to foresee weather or compare its variations. There are other signs of a coming change in the weather known less generally than may be desirable, and therefore worth notice; such as, when birds of long flight, rooks, swallows, or others, hang about home and fly up and down or low, rain or wind may be expected. Also when animals seek sheltered places, instead of spreading over their usual range; when pigs carry straw to their sties; when smoke from chimneys does not ascend readily (or straight upwards during calm), an unfavourable change is probable.
Dew is an indication of fine weather, so is fog. Neither of these two formations occur under an overcast sky, or when there is much wind. One sees fog occasionally rolled away as it were by wind, but seldom or never formed while it is blowing.
Remarkable clearness of atmosphere near the horizon: distant objects, such as hills unusually visible, or raised (by refraction), and what is called “a good hearing day,” may be mentioned among signs of wet, if not wind, to be expected.
More than usual twinkling of the stars; indistinctness or apparent multiplication of the moon’s horns; halos; “winddogs,” and the rainbow; are more or less significant of increasing wind, if not approaching rain, with or without wind.
Mr. Glaisher remarks, in the account of one of his recent balloon ascents:—“It would also seem that, when the sky is overcast and no rain falling, the Sun is shining on its upper surface, and both these conclusions agree with all my own experiences. That double strata or layers of clouds are indications of rain is shown by my recent observations; but it is one of those facts which have so far attracted the attention of some observers of nature as even to have passed into proverbs. My friend, Mr. Sopwith, tells me that in the mining districts, where he has resided so much, it is a common saying that ‘it will be rain to-day; the clouds is twee ply thick;’ by which, in their homely phrase, they clearly express that their expectations of rain are based on the observance of one range of clouds flying in the air at a higher elevation than another.”
It has been well observed that the old lunar theory, still implicitly received by country-folks, and held by many ladies as a fact of direct experience—the theory that weather is apt to change at the moon’s quarters, clearly applies rather to the earth than to any particular spot on it. And all the various complicated forms of that theory, invented to supply its apparent failures—such as that a change from fine to wet may be expected if the new quarter is entered on after midnight, and vice versâ for a post-meridian change,—are liable to the same objection.
The late Marshal Bugeaud, says the Emancipation, when only a captain, during the Spanish campaign under Napoleon I., once read in a manuscript which by chance fell into his hands, that from observations made in England and Florence during a period of fifty years, the following law respecting the Weather had been proved true:—‘Eleven times out of twelve the weather remains the same during the whole moon as it is on the fifth day, if it continues unchanged over the sixth day; and nine times out of twelve like the fourth day, if the sixth resembles the fourth.’ From 1815 to 1830 M. Bugeaud devoted his attention to agriculture; and guided by the law just mentioned, avoided the losses in hay time and vintage which many of his neighbours experienced. When Governor of Algiers, he never entered on a campaign till after the sixth day of the moon. His neighbours at Excideuil and his lieutenants in Algeria would often exclaim, ‘How lucky he is in the weather.’ What they regarded as mere chance was the result of observation. In counting the fourth and sixth days, he was particular in beginning from the exact time of new moon, and added three-quarters of an hour for each day for the greater length of the lunar as compared with the solar day.
Mr. Shepherd, C.E., appears to prefer the planet Jupiter to the moon, and has discovered an elaborate law for the variations of our English weather, except so far as the principle is affected by comets.
Mr. Shepherd is not quite without even higher authority. Sir John Herschel has publicly intimated his suspicion that the periodic expansion in the Sun’s spots had some close connexion with the extraordinarily wet summer of 1860, and in his article on Meteorology in the Encyclopædia Britannica, the same eminent authority has connected this periodic change in the Sun’s spots, which takes place in about twelve years, with the periodic time of Jupiter’s revolution round the sun (which is nearly the same in length), so that here we have an eminent astronomer half conceding the same very dubious principle—that causes which affect equally, if not the whole earth, at least all places which, in the diurnal rotation, are brought into the same relative position towards the sun or the planet, are the principal influences which determine our local weather.
Yet, if this be so, how does it happen that the year 1860, which was abnormally wet in Europe, was abnormally dry in many other parts of the world? If Mr. Shepherd be right in connecting this fact with the orbital position of Jupiter, or Sir John Herschel in connecting it with the large spots on the Sun, it would scarcely have merely affected the local distribution of heat; or, if it could, the means by which these causes rob England to burn India remain as dark as before.—Paper in the Spectator newspaper.
In one of his letters, Humboldt says that a Barometer should be considered as necessary on a farm as a plough: but farmers generally prefer to trust in the moon and other exploded nonsense to purchasing a reliable instrument that would repay them tenfold. A substitute, called Leoni’s Prognosticator, consists of a vial full of a clear liquid, in which swims a snowy substance. In fine weather that substance lies on the bottom, but before a storm it rises to the surface, with a tendency to the side opposite the quarter from which the storm is coming. The substances used are kept secret. An ordinary barometer indicates the density of the atmosphere. Leoni’s instrument evidently indicates its electric state, and for that reason we are of opinion that it is a better instrument to prognosticate the weather. The following is a substitute that will not cost more than 1s., and for aught we know it may be the identical thing itself. Dissolve some camphor in alcohol and throw into the solution some soda; the camphor will be precipitated in snowy flakes; collect these by passing the mixture through a filter and put them in a vial with clear alcohol, in which as much camphor as it would take has been dissolved. Cork it, place it where it will not be disturbed, and examine it every morning and night. This is termed a Storm-glass.
The intimate relation existing between the Climates of particular seasons, and the discharge of Icebergs from the great Arctic glaciers has long been perfectly understood and described by both British and American naval officers. But the quantity of ice annually released in the shape of bergs is so insignificant, majestic as those frozen masses are, in proportion to the quantity remaining behind, and to that annually engendered over the vast area of the Arctic continental icefields, that any difference in the amount of “average” annual discharge cannot materially disturb the balance. Nor is the disengagement of the bergs, when viewed on a large scale, a process depending on variable conditions. The slow downward descent of glaciers towards the ocean (which is now fully recognised as the result of a well-known law) is dependent on forces of such vast magnitude and in such constant operation as to admit of no perceptible modification owing to local atmospheric influences.
What does materially affect climate, however, is the variation in the annual range, Equator-wards, of the great Arctic currents, which convey on their surface not only the bergs, but the vast compact fields of pack-ice, extending over areas of many thousands of square miles, and thus bringing about a reduction of temperature, infinitely in excess of that produced by the bergs.
The exceptionally boisterous and rainy summer of 1860 was due to the much increased southward range, along the eastern and southern shores of Greenland, of the Spitzbergen drift, and was alluded to by Dr. Wallich, in some observations published by him at the close of that year.
So little is really known of this good Saint, that it is tedious to wade through a mass of more or less probable conjecture.
The facts of St. Swithun’s life seem to be that he was born near Winchester about the year 800—that he became a monk, and afterwards prior of the old abbey of that city, and was chosen by King Ecgberht the Bretwalda to be tutor of his son Æthelwulf, heir to the throne of Wessex. From 852 to 863, when he died, Swithun was Bishop of Winchester. He distinguished himself as an architect by building a bridge of stone and a tower to his cathedral, and as a Minister of State both to Æthelwulf and his successor, Æthelbald. In 971, more than a century after his death, he was exhumed, and “translated” and beatified by his successor, the famous Bishop Æthelwold, in the time of Archbishop St. Dunstan. Ridiculing, with Godwin De Præsulibus, the idea taken up by Lord Campbell, that Swithun was Æthelwulf’s “Chancellor,” in the modern sense of the word, Mr. Earle (formerly Professor of Anglo-Saxon at Oxford) claims for him the credit of having had a great share in the administration of that King’s policy, and especially in the education of his youngest son, the Great Alfred. Indeed, he surmises that Swithun was Alfred’s companion in his journey to Rome in 853, though the Saxon Chronicle says nothing about it. And he also argues that Æthelwulf’s much-debated dedication of the tenth of his land as tithes to religious purposes, in the year 855 (when the Northmen first wintered in England), was due to Swithun’s advice. “This was,” he says, “the culminating point of Swithun’s policy.” Equally baseless is the hypothesis that Swithun was the “intermediary,” the “prudent counsellor and successful diplomat” who averted civil war when Æthelwulf returned from his pilgrimage to Rome, bringing with him as wife the Frankish Princess Judith. It is more certain, we think, that Swithun’s name continued to be held in affectionate reverence among the people; and this probably led to his beatification by popular consent. The formal process of canonization had not yet been introduced.—Saturday Review.
Mr. Earle discusses the legend which connects St. Swithun with forty days of rain, and decides that it is wholly without foundation. Mr. Howard, the meteorologist, many years since, by his observations, gave a sort of currency to this notion; but it has since received its quietus in the following facts, from the Greenwich observations for 20 years:—It appears that St. Swithun’s day was wet in 1841, and there were 23 rainy days up to the 24th of August; 1845, 26 rainy days; 1851, 13 rainy days; 1853, 18 rainy days; 1854, 16 rainy days; and in 1856, 14 rainy days. In 1842 and following years St. Swithun’s day was dry, and the result was, in 1842, 12 rainy days; in 1843, 22 rainy days; 1844, 20 rainy days; 1846, 21 rainy days; 1847, 17 rainy days; 1848, 31 rainy days; 1849, 20 rainy days; 1850, 17 rainy days; 1852, 19 rainy days; 1855, 18 rainy days; 1857, 14 rainy days; 1858, 14 rainy days; 1859, 13 rainy days; and in 1860, 29 rainy days. These figures show the superstition to be founded on a fallacy, as the average of 20 years proves rain to have fallen upon the largest number of days when St. Swithun’s day was dry.
No event, or natural phenomenon which could be construed into such, is alluded to by any of the various authors who wrote histories of St. Swithun. On the contrary, the weather seems to have been most propitious during his translation. How then did the popular notion about St. Swithun’s Day arise? Most probably, as Mr. Earle remarks, it was derived from primeval pagan belief regarding the meteorologically prophetic character of some day about the same period of the year as St. Swithun’s. Such adaptations, it is well known, were frequent on the supplanting throughout Europe of heathenism by Christianity. In confirmation of this view it is to be observed, that in various countries of the European continent, the same belief prevails, though differences exist as to the period of the particular day in question. Thus, in France, St. Médard’s Day, (June 8,) and the Day of St. Gervais and Protais, (June 19,) have a similar character ascribed to them. In Belgium they have a rainy saint, named St. Godeliève; whilst in Germany, among others, a character of this description is ascribed to the day of the Seven Sleepers.
Mr. G. V. Vernon has communicated to the Literary and Philosophical Society of Manchester a Paper on the number of Days on which Rain falls annually in London, from observations made during the fifty-six years, 1807-1862. Howard’s Climate of London has been used for the years 1807 to 1831; the Philosophical Transactions for the years 1832 to 1840; and the Greenwich Observations for the years 1841 to 1862. During the entire period of fifty-six years, no month occurred in which rain did not fall.
The minimum number of days occurred in 1832, the cholera year, and 1834; the number of days being 86, 82 respectively. The maximum number occurred in 1848, the number being 223 days.
Taking the quarterly values, we find that rain falls on the greatest number of days in autumn, and the least in spring.
Taking the means of five yearly periods, there appears to be a kind of periodicity in the number of days on which rain falls; having a maximum in 1815 to 1817, and a minimum in 1845 to 1847.
A person may be killed by Lightning, although the explosion takes place at the distance of twenty miles, by what is called the back-stroke. Suppose that the two extremities of a cloud, highly charged with electricity, hang down towards the earth, they will repel the electricity from the earth’s surface, if it be of the same kind with their own, and will attract the other kind; and if a discharge should suddenly take place at one end of the cloud, the equilibrium will instantly be restored by a flash at that point of the earth which is under the other. Though the back-stroke is often sufficiently powerful to destroy life, it is never so terrible in its effects as the direct shot, which is frequently of inconceivable intensity. Instances have occurred in which large masses of iron and stone, and even many feet of a stone wall, have been conveyed to a considerable distance by a stroke of lightning. Rocks and the tops of mountains often bear the marks of fusion from its action, and occasionally vitreous tubes, descending many feet into banks of sand, mark the path of the electric fluid. Some years ago, Dr. Fielder exhibited several of these fulgorites in London, of considerable length, which had been dug out of the sandy plains of Silesia and Eastern Prussia. One found at Paderborn was forty feet long. Their ramifications generally terminate in pools or springs of water below the sand, which are supposed to determine the course of the electric fluid. No doubt the soil and substrata must influence its direction, since it is found by experience that places which have been struck by lightning are often struck again. A school-house in Lammer-Muir, in East Lothian, has been struck three different times.—Mrs. Somerville’s Connexion of the Sciences.
The inquiries into the chances of refuge from lightning have been attended with saving results. Here is an instance:
A few years since an awful thunderstorm occurred in the neighbourhood of Inkpen, Berkshire. Three men, named Martin, Buxey, and Palmer, were employed in mowing grass, when a storm of thunder and lightning broke over the field, and one of them suggested that they should run beneath a tree; Martin knowing that trees generally attract lightning, immediately remarked, “We had better go anywhere than under a tree.” Buxey and Palmer, however, as the storm was severe, and the hail was falling heavily at the time, ran and seated themselves beneath a large lime-tree, but Martin walked off to a cottage, and was safely sheltered. In about half-an-hour after the storm had abated, both Buxey and Palmer were found lying on the grass beneath the tree, quite dead from the lightning. The clothes of Buxey were found to be on fire, and the hair of Palmer was much scorched.
It has been demonstrated that Moonlight has the power, per se, of awakening the Sensitive Plant, and consequently that it possesses an influence of some kind on Vegetation. It is true that the influence is very feeble, compared with that of the sun; but the action is established, and the question remains, what is the practical value of the fact? “It will immediately,” says Professor Lindley, “occur to the reader that possibly the screens which are drawn down over hothouses at night, to prevent loss of heat by radiation, may produce some unappreciated injury by cutting off the rays of the moon, which Nature intended to fall upon plants as much as the rays of the sun.”
Even artificial light is not wholly powerless. Decandolle succeeded in making crocuses expand by lamplight; and Dr. Winn, of Truro, has suggested that the oxyhydrogen lamp may be made subservient to horticulture in the dark days of winter.
An extraordinary effect of Moonlight upon the human subject occured in 1863. A boy, thirteen years of age, residing near Peckham Rye, was expelled his home by his mother for disobedience. He ran away to a corn-field close by, and on lying down in the open air, fell asleep. He slept throughout the night, which was a moonlight one. Some labourers on their way to work, next morning, seeing the boy apparently asleep, aroused him; the lad opened his eyes, but declared he could not see. He was conveyed home, and medical advice was obtained: the surgeon affirmed that the total loss of sight resulted from sleeping in the moonlight.
Mr. Piesse, the well-known operative chemist, has thus popularly grouped some of the leading novelties of our age: