Chapter XXI: Letter XIX: gives a definition of the ellipsis, which would be a (15)

3. Besides these observers, two or three others, if not many more, less scientific, perhaps, but yet entitled to attention, have communicated to different newspapers their accounts of the same phenomena. “The metropolis,” says one of these, “was surprised on Tuesday night by a brilliant display of Northern Lights, which but very seldom stray so far south. The last which we beheld in London were in the autumn of 1804, about the end of September, or beginning of October; and the fancied prodigy filled all the superstitious heads, at the time, with fearful prognostics, and loosened the tongues of a hundred prophets. The spectacle, then, was truly magnificent. On Tuesday night (the 25th) the northern parts of the heavens displayed, about eleven o’clock, so ruddy a blaze, as to appear like the reflection of a mighty conflagration. An hour later, the red hue was gone; but the whole horizon, from the north to the east, was lined with _a thin cloud_, from which the rays of light rolled, or sudden rays flashed up, and as suddenly vanished, to appear in a different part.” “At about half past eleven o’clock,” says a second, “my attention was attracted to a singular appearance of light and streakiness in the sky. I observed it for nearly two hours. The sky, to the north, was obscured, for about fifteen degrees above the horizon, by a _dense_ stratum of black clouds; from the upper edge of this, the light became first apparent, extending from nearly north-east to north-west, exceeding considerably in power that arising from the moon just previous to its rising. From this broad stratum of pale yellowish light shot beautiful _pencils_, of a luminous, hazy appearance, up to the very zenith, changing momentarily in length and intensity. During this period, the wind blew gently from the south; and I frequently observed, that when it freshened [p400] a little, the Aurora Borealis became more brilliant in its appearance, sending beautiful coruscations of light, in rapid succession, towards the zenith, and frequently passing that point ten or fifteen degrees to the southward. I have been assured, by those who are well acquainted with this beautiful phenomenon, that they have not seen any appearance of it equal in brilliancy and beauty to this, for upwards of six and thirty years.” “Last night,” says a third, “we were favoured with that interesting phenomenon, the Aurora Borealis, or Northern Twilight, which so often amuses and cheers our neighbours in the north, but seldom, I believe, is seen in our latitude. It was without those varied colours,” adds this writer, “which cause it to be a grand spectacle in those regions.” “Not far from the horizon,” he adds, “in the northern hemisphere, were transparent bodies of light, _eclipsing_ the brightness of the stars, which, however, were perceptible through it. From hence, beams of light, varying in degrees of brightness and breadth, shot up towards the zenith; here streamers of light flew from the east to the west, and from west to east. The southern hemisphere was cloudless, the stars shining with brilliancy. By the light of this phenomenon, I could discern the time of night, which was between eleven and twelve, as well as other objects, as they appear on a moon-light night, when the moon is obscured by clouds.” “The sky in the north,” we are told by the fourth, “appeared as if a light shone from behind some dark masses of clouds. As I approached Hampstead, the silvery light was gradually tinged with rosy spiral streams, like those which sometimes precede the rising and follow the setting sun. These spiral red streaks did not appear to move quickly; but they were subsequently followed by the _merry dancers_, which fully maintained the character bestowed upon them by our northern neighbours. After passing through Hampstead, I crossed the heath, and came down what is called North-end Hill, to Golder’s Green, Hendon. When you arrive at the foot of the hill, you enter upon the open part of Golder’s Green, where you have a clear and unobstructed view of the sky from west to north. I never shall forget the grandeur of the scene which awaited me there. A continuous border of dark cloud skirted the horizon completely from west to north, whilst [p401] from behind it, incessantly and rapidly shot up the most beautiful coruscations of white light, which, being relieved by the dark border, added double brilliancy to the ever-shifting scene.”

* * * * *

VI. But, after transcribing these respective accounts, it may be permitted, for the purpose of uniting them with that submitted in the preceding pages, to remark,

1. That the account by Mr, Adams, of the appearance worn by the Aurora at an early hour in the evening, is, no doubt, entirely correct; and that it is easy to understand, from this description of that early appearance, why little observation was attracted to the phenomenon till about eleven o’clock at night, the time assigned, as well in this, as in all the other accounts, for the commencement of the phenomenon.

2. That the “streaks of a pale white light,” which Mr. Adams describes as proceeding, a short time after eleven, “_from_ the clouds,” must be understood, as stated by the writer last quoted, as proceeding “_from behind_ the clouds;” that, when the astronomical writer at Deptford speaks of Ursa Major and other stars being seen through the Aurora, it must be recollected, that, perhaps, this remark should apply to the medium of the thin and shifting lights in or near the zenith; and,

3. That it is with respect to the “broad streak, curved,” of Mr. Adams; the “_two_ red beams of light,” of the astronomical observer at Deptford; and the “arch” of the present description, that the principal, if not only discordance obtains. Neither of the other three writers appears to have seen any thing, whether of one “broad streak, curved,” and “varying in colour from a deep copper hue to a red,” or of “_two_ red beams,” as spoken by the writer at Deptford; while, in each of the three accounts in which that part of the phenomenon is actually referred to, the descriptions are materially dissimilar:—

1. The writer at Edmonton mentions only a single streak, while the writer at Deptford speaks of _two_.

2. The writer at Edmonton describes his single streak as curved, while the writer at Deptford says nothing of curvature; and, in describing the position of the beams as “perpendicular to the horizon,” may seem to leave no curvature to be understood. [p402]

3. The writer at Edmonton seems to lift his “broad curved streak” much above the horizon; for he first places a small dense cloud 30° above the horizon, and, then, his broad streak above the cloud; thus describing a curve of which the situation was near the zenith, while the writer at Deptford is describing “two red beams,” standing perpendicularly to the horizon.

4. The writer at Edmonton places his “broad streak, curved,” “in a N.N.E. direction;” while the writer at Deptford records “two red beams of light, seen in the easterly and westerly direction.” Lastly,

5. The writer at Edmonton seems to make coruscations, “incessant and remarkably bright,” dart from his “broad streak, curved;” while the writer at Deptford seems only anxious to place his “two red beams,” as perpendicular pillars, standing on either side of the _magnetic meridian_.

* * * * *

VII. And, from the whole of this, from the total silence of four accounts, and from the extreme discordance of the other three, the present writer presumes to draw the following inferences, including that of the accuracy of his own original statement:

1. That the two perpendicular red beams of light, of the writer at Deptford, should be joined with broad curved streaks of a deep copper, or red hue, of the writer at Edmonton, to complete the _arch_ which has been spoken of in the foregoing pages.

2. That this _arch_, or curved streak, with its feet east and west, sent forth no coruscations itself; but that the coruscations rose beneath it, and passed above it.

3. That it was described upon the clouds only; was no part of the Aurora; and, from its connexion with the clouds only, had an evanescence which, on the one hand, was the cause of the various descriptions, and, on the other, of no descriptions at all. The present writer observed this part of the phenomenon from its beginning to its ending. He saw it rise in the west, extend itself from the north, and descend in the east; and he thinks it reasonable to ascribe the variations concerning it, in the coincident narratives, to the different points of time to which alone they really refer. The writers at Edmonton [p403] and Deptford seem to have had their attention fixed upon it at different epochs of its progress; and all the four other writers, who have been cited, seem to speak of a time subsequent to its disappearance. The present writer does not recollect the small cloud below it, spoken of by Mr. Adams; but he well remembers the clouds above it, and along and near the northern edge of which it seems to be formed. He does not recollect seeing its definite _southern_ outline contrasted with the azure sky; but he well remembers seeing that outline contrasted with the dark clouds above it, or to its southward; and also the contrast of its definite, _northern_ outline, as contrasted with the azure sky beneath.

* * * * *

VIII. It is necessary to take notice, also, of what is said above, by the astronomical observer at Deptford, as to the “flashes converging to the zenith,” and, further, of the omission, both by this writer and by Mr. Adams, to speak of the curved beam, streamer, or coruscation, to the east of north, as described above. The whole veracity of the foregoing description depends upon the denial of a uniform convergence of the streamers, pillars, columns, or coruscations toward the zenith; nor was it, in all probability, the intention of the writer at Deptford, to assert any such convergence, but only to speak of those coruscations, or shifting lights, in the zenith, which are described by Mr. Adams as crossing each other from east to west. It is remarkable, at the same time, that neither the one nor the other of these writers have mentioned that direct reverse of convergence which marked the general figure and arrangement of the streamers or columns of the Aurora, and which was so opposite to what would have been given to it by the phenomenon of convergence. Indeed, the violent curve of the extreme column to the N. E. or N. N. E., shrouded, too, as that column was with a body of dense vapour through which its light appeared of a deep and dull red colour, might make the description of this itself answer to the “broad streak, curved,” of Mr. Adams, if we were not certain, from other particulars mentioned, that Mr. Adams really refers to the curve which formed part of the _arch_. For the rest, no mention of the real directions of the several columns having been made by any observer of the Aurora of the 25th [p404] of September but himself, and especially none of the outward curve of the easternmost column, it is satisfactory to the writer to have found an account of an appearance similar to this last, in an Aurora of which he will presently have occasion to speak.

* * * * *

IX. Finally, there is an observation to be made upon that part of the description, by the second correspondent of the newspapers, where it is said, that during the appearance of the coruscations in the zenith, “the wind blew gently from the south,” and the spectator “frequently observed, that when it freshened a little, the Aurora Borealis became more brilliant in its appearance;” to which it may also seem the writer’s intention to add,—“sending beautiful coruscations of light, in rapid succession toward the zenith, and frequently passing that point, ten or fifteen degrees to the southward.” Now the reality of any dependence of the light and motion of the Aurora upon the freshening of the breeze, would seem too strongly to affect the question of the nature and action of the _auroral matter_, to be admitted without cautious examination. In truth, what was it that constituted the luminous matter which we saw in the zenith? The stars were visible through it. But for luminous appearances that flew or skimmed along the heavens, we should have said, that the latter were clear, and that there was nothing but the purest atmosphere between the earth and the heavens. Was it, then, the atmospherical matter which was thus illuminated, and which, being ruffled by the breeze, can be supposed to have really exhibited the appearances described by this writer, or, was it not, rather, illuminated _auroral matter_, which was shot through the atmosphere; and, if this last, how are we to understand that its brilliance, and still less the frequency and vigour of its coruscations, could have been affected by the freshening of the breeze?

* * * * *

X. But, taking, now, a final leave of the description of the Aurora of the 25th of September, and of the observations specially suggested by it, let us here examine the several particulars which are commonly offered as part, at least, of its true history; an undertaking, for the greater convenience of which the account given in a modern work of much and [p405] deserved reputation, shall be quoted and considered sentence by sentence, as follows:

1. “AURORA BOREALIS, _Northern Light_, or _Streamers_; a kind of meteor, appearing in the Northern part of the heavens, mostly in the winter time, and in frosty weather.

2. “It is in the Arctic regions that it appears in perfection, particularly during the solstice.

3. “In the Shetland Islands, the Merry Dancers, as they are called, are the constant attendants of clear evenings, and prove great reliefs amidst the gloom of the long winter nights.

4. “They commonly appear at twilight, near the horizon, of a dun colour, approaching to yellow; sometimes continuing in that state, for several hours, without any sensible motion, after which they break out into streams of stronger light, spreading into columns, and altering slowly into ten thousand different shapes, varying their colours from all the tints of yellow to the obscurest russet.

5. “They often cover the whole hemisphere, and then make the most brilliant appearance.

6. “Their motions, at these times, are most amazingly quick, and they astonish the spectators with the rapid change of their form.

7. “They break out in places where none were seen before, skimming briskly along the heavens; are suddenly extinguished, and leave behind a uniform dusky track.

8. “This again is brilliantly illuminated in the same manner, and as suddenly left a dull blank.

9. “In certain nights, they assume the appearance of vast columns; on one side of the deepest yellow, on the other, declining away till it becomes undistinguished from the sky.

10. “They have generally a tremulous motion from end to end, which continues till the whole vanishes.

11. “In a word, we, who only see the extremities of these northern phenomena, have but a faint idea of their splendour and their motions.

12. “According to the state of the atmosphere, they differ in colour.

13. “They often put on the colour of blood, and then make a most dreadful appearance[124].” [p406]

1. Now, with respect to the first and second of the sentences here transcribed, there seems reason to doubt the accuracy of the account which almost limits the appearances of the Aurora to the “winter time,” to “frosty weather,” and especially to the winter “solstice.” The frequency with which the season approaching to Christmas, or that of the winter solstice, is distinguished by the occurrence of weather peculiarly mild, insomuch that, almost every year, the period is marked by observations upon what is annually called the extraordinary and unseasonable genialness of the weather, cowslips blooming, leaves budding, and birds building their nests; this frequency of a mild temperature of the air about the period of the winter solstice, may justify, even under a general view, a doubt of the accuracy with which, as things of course, the winter solstice, and frosty weather, are spoken of as arriving in conjunction. But, that the appearance of the Aurora Borealis is not peculiar, either to the occurrence of frosty weather, or to the period of the winter solstice, whether the two latter phenomena are related or otherwise, seems probable, as well from the mildness of the weather at the late appearance, as from the various seasons of the year in which the few others described in our books are recorded to have presented themselves. The earliest mentioned was seen in London in the year 1560, on the 30th day of January. The next was in 1564, on the 7th of October. The next, in 1574, on the 14th and 15th of November. The two next, observed in Brabant, in 1575, on the 25th of February, and 28th of September. The next, at Wurtemburg, as we are assured by Meestlin, seven times, in the year 1580. The next, in an extraordinary manner, in the months of April and September, 1581; and in a less degree, at some other places, in the same year. The next, observed all over France, in 1621, on the 2nd of September. The next in 1707,and 1708, during which two years the Aurora was witnessed five times. The next, in the month of March, in 1715–16. The next, in 1737, on the 16th of December; that seen in London in 1791, of the month of which the writer is uninformed; another in 1803, or 1804, at the latter of September, or the beginning of October; and this, of 1827, on the 25th of September. But, from these statements, it is now seen, that, [p407] exclusive of appearances of the Aurora in respect of which the month is not particularised, eight of the different months of the year occur by name; that is to say, the months of September, October, November, and December, January, February, March, and April; leaving only four months (May, June, July, and August, the identical summer-months of the Polar regions, or months during which the sun visits the Polar horizon!) hitherto undistinguished by the phenomenon of the Aurora, and almost establishing, as the season of its occurrence, not the middle point of the winter solstice, but the whole period extending, in general terms, from the autumnal equinox to the vernal, beginning at or before the first, and ending at or after the last; or, what may be called the entire winter of the northern hemisphere, or the period during which the sun’s course is to the southward of the tropic of Cancer; a deduction from the scanty data offered by such archives of the phenomenon as we possess, not, perhaps, of trifling importance toward the establishment of the true theory of the cause, as well as of the purpose of its being.

2. The third sentence, where it describes the Aurora Borealis as the _constant_ attendant of clear evenings in the Shetland Islands, and thereby a great relief to the gloom of the long winter-nights, is probably tainted with errors in regard to the phenomenon, such as affect its whole history and philosophy. The suggestion has just been hazarded above, that at least considerable displays of the Aurora are probably almost as rare, even in the Arctic regions, as in climates further south; and the truth of this persuasion, as the writer anticipates, will fully appear below. In the sentence now referred to, the word “constant” should, at least, give way to “frequent,” if not to “often;” and a distinction should be allowed for, between those feeble appearances which alone, it may be suspected, are even _often_ beheld in the Shetland Islands, and those extraordinary displays which make themselves visible to their southward.

3. The fourth of the above sentences, in which the Aurora is said to appear commonly at twilight, will have been seen to agree with the time assigned for the commencement of the Aurora in the late example; and this, when coupled with the [p408] observation in the third, that, in the Shetland Islands, it is the constant attendant of _clear_ evenings, will seem to suggest, what, indeed, will probably be easily agreed to, that the Aurora, in itself, is peculiar neither to clear evenings nor to evenings at all; but is in activity during the twenty-four hours, or without intermission; though, to be visible to human eyes, first, the atmosphere must be dark, and, secondly, it must be more or less clear. It may also be thought apparent, from the terms of the twelfth and thirteenth sentences, that too much has not been said by the present writer, of the degree in which the peculiar spectacle, upon each separate occasion, depends, not alone of the proper and really uniform features of the Aurora itself, but also of the atmosphere through which it is seen, with the appearance of which its own appearance is combined; and of the consequent value of a careful separation of the real phenomena of the Aurora, from the adventitious phenomena of the intervening and surrounding atmosphere. That the colours which, whether visibly connected with the atmosphere or otherwise, are displayed during the appearance of the Aurora Borealis, are wholly derived from the atmospherical medium through which we behold it, and that the Aurora itself exhibits only a pure white light, is what the writer greatly inclines to suspect, and what may seem to be rendered still more credible by that which is reported by those who have obtained a partial glimpse of the Aurora _Australis_, or corresponding phenomenon of the south. This is described, by Mr. Forster, who sailed round the world with Captain Cook, as consisting in “long columns of clear white light;” but the whiteness, in the eyes of the narrator, seemed to establish a difference, instead of a similitude, between the Auroræ Australis and Borealis, Mr. F. wholly overlooking the explanation which his own account supplies! “These columns,” says he, “though in most respects similar to the Northern Lights (Aurora Borealis) of our hemisphere, yet differed from them in being always of a whitish colour, whereas ours assume various tints, especially those of a fiery or purple hue. The sky was generally clear when they appeared, and the air sharp and cold, the thermometer standing at the freezing point.” Now this text is its own commentary. The [p409] Aurora could not have been seen if the sky had not been more or less _clear_. But the sky was _very clear_; and this because the weather was _severely frosty_. The thermometer “was standing at the freezing point.” The weather was settled frosty, and therefore settled clear; for the Aurora appeared for “several following nights.” The atmosphere, therefore, was clear; there was neither cloud nor fog, and thence the whiteness of the Aurora. But these views of the Aurora _Australis_ were partial occurrences, and were characterised, as we must conclude, by the state of the atmosphere at a particular conjuncture, or at a particular season of the year. In point of fact, the Aurora was seen on the 16th of February, 1773, in latitude 58° S. This was the beginning of the Australian winter, and it might be a very cold, and therefore a very clear beginning. But the atmosphere of the southern half of the globe is not always thus translucent; and when it is otherwise, we may depend upon it that the columns of its Aurora “assume various colours; especially those of a fiery and purple hue,” more or less like our own. A friend of the present writer was in the same latitude (58° 12′ S.) in the month of March, a few years since; and, upon asking that gentleman whether he had ever beheld an Aurora in the Southern Hemisphere, his answer was in the negative. The season of his visit, however, was a month later in the southern winter than the visit of Messrs. Cook and Forster; the weather was thick and sleety; it was unfavourable to any view of an Aurora at all; but, had the phenomenon happened to present itself, its appearance, we may believe, would not have presented that of a uniform, clear, white light.

4. In the fourth and sixth sentences, what is said of “change of shape,” and “change of form,” is of a nature exceedingly to mislead such as, never having themselves witnessed the phenomenon, may desire either to figure it to their imagination, or to reason upon its appearances. In reality, there is no such change of shape or form as the words naturally suggest to our ideas; the forms, under all changes, are still linear; and the actual changes, as to form, are limited to such changes only as can be produced with the single material of lines, lengthened, shortened, varied in their direction, and now fixed, now shaken, now darting; and now joined in rapid and intermingling motion. [p410] Add, that these lines are luminous, and varied in colour from white to yellow, red, and crimson, and, sometimes, perhaps, to purple and to violet; that they play, in the lower heavens in a field of light, and in the upper over a sky of blue; and the picture of the Aurora Borealis is well nigh complete. The observation in the ninth sentence, that the vast columns, of which, upon some occasions, the Aurora displays the forms, are of a deep yellow upon one side, which, upon the other, fades gradually into that of the sky, is to be understood, as expressing, that, as in the late example, the outer edges of the columns, or those next the dark or unillumined portion of the horizon, are sharp and strongly defined; while the inner ones are less distinguished from the general field of light in which they stand; and which distinction, after all, is but a delusion of the eye, which more readily distinguishes the variation of colour in the outer edge, which is so strongly relieved by the dark and colder-coloured part of the sky, than the colour of the inner part and edge of the column, which, more or less, approaches that of the ground behind it.

5. Sentences seven and eight appear to the present writer to convey the most accurate description possible, of the appearance of the Aurora in the _zenith_. The “dusky track,” which remains after the lights which have enlivened it are extinguished, and in which they are so often seen again, may seem to attest the justice of his opinion, that these appearances in the zenith are no other than the far-projected tops of the columns which have their bases in, or rather below, the horizon; tops which, while they fill the southern half of the zenith, to the view of spectators under our parallel, must gradually descend toward the horizon, in the eyes of such as behold them further and still further to the south; till, like the topmast of a receding ship, they first scarcely remain discoverable above the convexity of the surface intervening, and finally dip and sink beneath it. But, upon this assumption, the appearance, and therefore office, of the Aurora Borealis, must be conceived as extending far to the southward of even our own island; and the statement, as in the eleventh sentence, becomes more or less inaccurate, that “only the extremities of these northern phenomena” are witnessed by ourselves. In reality we are [p411] ourselves inhabitants of the Northern hemisphere; and the relationship of the Aurora to the wants of the whole hemisphere is more extended, perhaps, than we have commonly imagined. It is even a contradiction to say, as in the eleventh sentence, that we see only the extremities, that is, the Southern extremities of these Northern phenomena, after having said, in the fifth sentence, that “they often cover the whole heavens, and then make the most brilliant appearance;” unless, indeed, in both of these remarks reference is made to the spectacle beheld under more Northerly parallels, a reference which is further suggested, together with their apparent origin, in the terms of a description by Gmelin, to be cited below, of the Aurora as beheld upon the coasts of the Icy Sea; If the Aurora, there, or upon the banks of the Lena or Yenesei, is seen to rise in the north, but yet to stretch itself over the whole hemisphere, it must follow, that its “extremities,” that is, its southern extremities, so far from being all that is seen in these situations, are really projected, on those occasions, so far to the southward, as to escape the ken of our northern optics; a fact of which the explanation must be familiar, inasmuch as, owing to the convexity of the surface of the globe, the horizon of every part is narrowly bounded, whether upon the South or upon the North; whence it results, that any celestial, or even atmospherical appearance, stretching only a little way beyond us to the Southward, or toward the East, or toward the West, must soon reach the horizon upon either of those sides, and thus cover all that, to the eye of any individual, is visible of the “whole hemisphere.”

6. But the description, by Gmelin, of the Aurora, as seen upon the shores of the Icy Sea, and more than all, the simplicity with which the naturalist is disposed to fix its birth-place in that precise interval of the earth’s surface which divides the mouth of the river Yenesei from that of the river Lena, in the North-east of Asia, (a spot so far to the _North-eastward_, too, of our own!) while it may possibly explain the origin or bearing of remarks, that it “sometimes covers the whole hemisphere, and then makes the most brilliant appearance,” will also afford something of an answer to such as, with the writer quoted above, seeking to connect the Aurora Borealis with the [p412] Magnetic Pole, would discover its same birth-place, or focus, in the _North-west_, or nearer to the North-west of America, than to the North-east of Asia! It may furnish a reply, also, to Gmelin himself, who, though he tells us that, even upon the banks of the Lena and Yenesei, the Aurora is still seen to rise to the North or North-east of those situations, yet imagines those very banks to be its “real birth-place;” for is it not plain, in the meantime, and this from the very statement of the author, that, travel as far northward, or north-eastward, as we will, the birth-place of the Aurora still retires from our feet; that, even upon the shores of the Icy Sea, the joyous phantom is still to our Northward, or North-east, and that we may reasonably conclude, that even a voyage upon that sea would not carry us to the cradle in pursuit; that, in short, at the North Pole, we should still behold it rise in the North, or the North-east, or the North-west; that we might sail down the Western Hemisphere, and yet only discover, that the Aurora was now in the North behind our backs, as it had been before in the North before our faces; and that, in short, so long as we do but admit its existence in the North, the particular soil or sea is best described in the most general terms:—

“In Nova Zembla, or the Lord knows where!”

The search, too, for the paternal hearth of the Aurora Borealis in any particular division of the Northern Hemisphere, and especially the attempt to find it at the Magnetic or Electric Pole, is, perhaps, so much the more hopeless, after ascertaining, as above, that each hemisphere has its Aurora; and after concluding, as we may have been led to conclude with reason, that each Aurora, other things equal, resembles the other! What is remarkable, also, is that, in the Southern Hemisphere, as well as, according to Gmelin, in the Northern, it is to the Eastward, or to the East of North, that the Aurora has its apparent focus. “A beautiful phenomenon,” says Mr. Forster, (Feb. 17, 1773, lat. 58° S.) “had been observed during the preceding night, which appeared again this and several following nights. It consisted of long columns of white light, shooting up from the horizon to the eastward, almost to the zenith, and gradually spreading over the whole southern part of the sky. These columns are gradually bent sideways [p413] at their upper extremities; and, though in most respects similar to the Northern Lights (Aurora Borealis) of our hemisphere, yet differed from them in being always of a whitish colour; whereas ours assume various colours, especially these of a fiery or purple-hue. The sky was generally clear when they appeared, and the air sharp and cold; the thermometer standing at the freezing point.” This occasional bending of the columns, “sideways at their upper extremities,” instead of uniform convergence toward the zenith, observed by Mr. Forster in the Aurora of the South, is plainly the same peculiarity which was recently witnessed in London, in the Aurora of the North, and a circumstance which, in whatever way explained, assists in the identification of the natures of the two phenomena; and, if we are still to hesitate, upon account of the whiter light of that of the South, let us believe that particular to originate in some peculiar constitution of the Southern atmosphere, from which, in one way or another, not here to be discussed, the cause of the difference may offer itself. But Gmelin’s account of the Aurora of the North, to which the attention of the reader has already been called, is that which is here required to follow. It is to serve to illustrate, as will be remembered, much of the foregoing: “This Northern Light,” says that author, “begins with the rising of single light pillars in the North, and almost at the same time in the North-east, which, gradually increasing, fill a large space in the heavens, rush about, from place to place, with incredible velocity, and finally almost cover the whole sky, up to the zenith: the streams are then seen meeting together in the zenith, where they produce an appearance as if a vast tent was expanded in the heavens, glittering with gold, rubies, and sapphires. A more beautiful spectacle cannot be described; but whoever should witness such a Northern Light for the first time, could not behold it without terror; for, however beautiful the illumination may be, it is attended, as I have learned from the relation of many persons, with a hissing, crackling, and rushing noise, throughout the air, as if the largest fireworks were playing off. To describe what they then hear, they make use of the expression, ‘Spolochi chodjat;’ that is, ‘The furious army is passing!’ The hunters, who, upon the confines of the [p414] Icy Sea, follow the chase of the blue and white foxes, are often overtaken in their excursions by the Northern Light; and, upon this occurrence, their dogs are so much frightened, that they will not move, but cower obstinately upon the ground till the noise is over. The weather, after the appearance of the Northern Light, is usually clear and calm. I have heard these accounts, not from one person only, but from many of those who have spent several years in these very Northerly regions, and inhabited different countries from the Yenesei to the Lena, so that no doubt of its truth can remain; for here seems to be the real birth-place of the Aurora Borealis.”

8. Upon this statement itself, it is only needful to remark, that the rising of the pillars in the North-east, or to the East of North, rather than to the North-west, or West of North, almost at the same time with their first appearance in the North, is not, perhaps, even as seen between the Lena and Yenesei, so uniformly the case as M. Gmelin may have been led to believe; and that, at all events, as above described, the progress of the late display, observed in London, was, first from North to West, and afterward from West to East; the North being always the centre, or always light, while the West and East were changed. The covering of the whole sky, and the splendour of the scene produced, have been the subject of previous remark; and the observation, “that the streams (previously called pillars) are then seen meeting together in the zenith,” entirely corroborates what the present writer has said of the nature of the lights seen skimming across the zenith, and across each other, and the deduction which he has thence made, that the luminous appearances in the zenith are the summits of those very pillars of which the bases are on or below the horizon. The clear and calm weather which, on the shores of the Icy Sea, commonly follows the appearance of the Aurora is, in some degree, in concord with the phenomena of its recent appearance in London; where, without any material change in the temperature, a succession of clear, calm, and bright days supervened, within a day or two of the Aurora. As to the hissing, crackling, or rushing noise, which is said to accompany the Aurora in the more northern regions, and which has sometimes been compared to that of the furling and [p415] unfurling of flags, there is nothing difficult, (knowing what we do of the noise of winds and of thunder,) in admitting its probability, unless what may arise from the consideration, that the noise might, or might not, be expected to be heard, where-ever the phenomenon is to be seen. But the most striking and important truth, communicated in the foregoing account, is that which we cannot but rigorously infer from the collective testimony of two very distinct descriptions, which is afforded in two of the concluding sentences. It consists in that real _infrequency_, as well in the Northern, as in the Southern Hemisphere, of the appearance of the Aurora; an _infrequency_ the knowledge of which is so essential to the true history of the phenomenon, and therefore to its true philosophy, and consequently to much of the history and philosophy of nature at large;—an _infrequency_ which the present writer has given notice of above, as a proposition for which, in dissent from all received authorities, he will contend; and upon the opposite account of which matter, in the general account quoted, he has already requested the reader to suspend his judgment. It is obvious that, as a natural phenomenon, an Aurora Borealis, which, though _constantly_ experienced in the more Northerly regions, is but rarely observed in the more Southern; that is, an Aurora Borealis which, though familiar to the Samoiede, the Laplander, and even the Shetlander, is an extraordinary, and a terrific, or at least a marvellous event, to the Italian, the Frenchman, and even to the Englishman; it is obvious, that such an Aurora Borealis, _constant_ in its occurrence a little further to the Northward, and almost the solitary spectacle of a generation a little further to the South, is, as a natural phenomenon, a very different thing from an Aurora Borealis which, though far enough to the South, sufficiently frequent in comparatively trivial magnitudes and lustre, is seen, either in the South or in the North, in its greatness, and in its splendour, but yet rarely, and with, perhaps, almost equal rareness; it is obvious that, as natural phenomena, and not less so as sights connected by mankind with their own fortunes, the two things now described are exceedingly unlike as matter of history, and equally so as matter of philosophy. If we are simply to record the occurrence, it is one thing to speak of a phenomenon [p416] which, in the South, is seen only at long intervals, while it is a “constant attendant” in the North; and another thing to speak of that which, whether in the South or in the North, is equally rare, and equally out of the “constant” course of nature. If we are to write the history of nature, it is one thing to relate, that such phenomena, or rather others, infinitely more splendid, more terrific, or more marvellous, than that which was witnessed in London, in the month of September in this year, or in the same month some three-and-twenty years ago, or else some six-and-thirty, and, to judge by experience, is not to be looked for, in the same city, during twenty or thirty years again;—it is one thing to relate that, in the Shetland Islands, such a spectacle is a “constant attendant of clear evenings,” and another thing to relate, that though, perhaps, on clear evenings, in the Shetland Islands, some small displays of the Aurora are not unfrequently perceived, yet, that such an exhibition as has recently been witnessed in London, and still more, such as, more effulgent, and more extended, and more vigorous, and even coloured by the atmosphere into the terrific;—that those exhibitions, in short, of which our naturalists and men of science would persuade us, that, while beheld nightly by those of the North, they are known to us by very faint examples alone;—those exhibitions,—that those extraordinary examples of the brightness and vigour of the Aurora—are as rare, or almost as rare, not only in the Shetland Islands, but in Iceland, and on the shores of the Icy Sea, as in the streets of London themselves! It is obvious, too, that if we are to speak of this phenomenon philosophically, if we are to attempt to explain its origin and use,—its source in the natural elements, and its office in the natural economy; here, too, the solving of this question of the _frequency_ or _infrequency_, the _constancy_ or the _inconstancy_, of these mighty exhibitions, even in the North, and under the Pole itself, is matter of foremost importance. And what is the testimony, upon these heads, which is borne by the accounts collected by Gmelin? Is the Northern Light of the German naturalist, the apparently constant attendant of clear evenings, even in the countries between the Lena and the Yenesei? Is the spectacle, and the atmospherical hurley, which seems to rush over the [p417] hunting-grounds of the hunters and their dogs, and which frightens the very dogs, and pins them to the ground till it is passed, or has seemed to pass; is this the “constant attendant of clear evenings,” or, is it a prodigy so uncommon as to defy familiarity? But, if this evidence is insufficient, let us look to what is said of its influence, in these countries, on the subsequent state of the atmosphere. So far from the Aurora being an attendant or follower of clear evenings, it seems that clear evenings follow the Aurora! It is said, that after its occurrence, clear and calm weather is customary to follow; and, here, the expression itself is implicative of the rarity of the occurrence. If it were constant, how should this result come to be noticed; and, indeed, if the Aurora Borealis were the constant attendant of each twenty-four hours, and if clear weather were usually in the train of the Aurora Borealis, how could it ordinarily happen, that there should be any thing else than clear weather, in the countries visited by the Aurora, or any foul weather for the Aurora to dispel? Yet, such is the established prejudice concerning this supposed frequency of the more powerful displays of the Aurora in the climates further to the North than our own, that a writer, quoting the very statement above, absolutely prefaces it with the remark, that Gmelin, in pointed terms, speaks of the Aurora as “frequent,” as well as “very loud,” “in the North-eastern parts of Siberia[125]!” A simple perusal, in the meantime, is sufficient to show, that Gmelin says nothing affirmative as to its _frequency_; while a slight consideration of the facts which he adduces must satisfy us, as no doubt they satisfied Gmelin himself, that the occurrence, even in Siberia, is actually _infrequent_!

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XI. In reference, however, as well to the image presented above, of “a vast tent expanded in the heavens, glittering with gold, rubies, and sapphires;” as also to many less ambitious and figurative descriptions of the spectacle of the Aurora Borealis, (not excepting that indicted by himself,) the author is anxious to suggest a caution against the too exaggerated conception of the realities intended. Words, [p418] upon such occasions, are rarely more than imperfect pictures, presenting but feeble likenesses, and either deficient or excessive in the amount of beauty, or of the reverse, of whatever kind, which they attempt to copy from their originals; and the inconvenience is seriously great, whenever the object portrayed is wholly strange to the mind before which it is placed. The imperfect power, both of words and written characters, to convey precise, and sometimes even tolerable ideas, of the objects, either sensible or abstract, which they are intended to represent, and the superior intelligibility so often belonging to diagrams or figures, or other resources of the art of drawing, (the primitive, and, for so many purposes, the most instructive mode of writing[126],) would have led the present writer, had time permitted, to endeavour, as often as possible, to elucidate by such means the several parts of the foregoing observations; but which means, at last, and in reference to the actual phenomena of the Aurora, would necessarily fail to convey the due, and yet no more than the due impression, to such as are wholly without its ocular acquaintance. We are little aware how much, upon ordinary occasions, our understanding of words heard or read is assisted by our previous knowledge of the sensible objects, or of the acquired notions, to which they refer; and the examples would be endless, of the sensible objects preposterously misconceived, as well as the propositions made false or ridiculous, through the frequent inadequacy of words to communicate truths entirely new [p419] to the disciple. Even the history of opinions concerning the Aurora Borealis itself, might be cited upon this very point.

The ordinary and natural resource, in such circumstances, is comparison; but even comparison has been the source of great and endless errors of description. Of the degree of resemblance proposed between the known and the unknown, there is no common measure for the minds of the hearer and the listener, and the point or points of comparison intended by the first must often be mistaken by the second; or, if reference is made to a similitude under one aspect, the imagination conceives a resemblance also under another: thus, if it is said, that an unknown animal is as _large_ as a horse, the idea of the _figure_ also of a horse, is apt to be attached. A modern English work of science premises, upon the subject of the Aurora Borealis, that its appearance is so well known as to render description needless. It is true that the work referred to is printed in the Northern part of the island, where the phenomenon is doubtless more familiar than in the Southern; but, in the foregoing pages themselves, it has, perhaps, been demonstrated as probably certain, that if it is any where sufficiently known to render description trite for the common eye, it has at least never hitherto been described with sufficient precision for the aid of speculative research. To attempt to explain its _cause_, and to relate its entire history, its _appearance_ must first be either observed or described with accuracy; and we have seen, above, that some of the most scientific reasonings which have hitherto been offered as to the former, are wholly inapplicable to the true peculiarities of the latter.

Considered simply as a visual object, and as a meteor differing from all others, and especially from all other luminous meteors, in this, that its duration extends to hours, if not to days and months; the only resemblance, perhaps, that can be suggested, is to that description of lightning which is called _heat-lightning_, the frequent companion of our summer-evenings. But, here, the similitude is inexpressibly feeble; since heat-lightning has nothing, either of the splendour, the volume, or the beauty of the Aurora; and since the light of the latter, however mobile, varied, and, from time to time, increased and diminished in itself, is yet, as to general effect, continuous and [p420] steady. There remains, then, but to compare the phenomenon of the Aurora with the rising or the setting Sun. In both of these latter, as in the Aurora, the light is in the horizon, and that light is shot upward, perpendicularly, or obliquely, toward the zenith or toward the right and left; and both of these, like the Aurora, are more or less constantly attended with a variety of colouring, similar in hue if not in depth, and always beautiful, and often gorgeous. With the _Sun_, and with the beams of the Sun, ancient description, in point of fact, has confounded the _Aurora Borealis_, to the degree, perhaps, of giving origin to some of the ancient and poetical descriptions of the Sun, utterly inappropriate and inexplicable as understood of that day-star, but easily recognised in the Aurora; yet the dissimilitudes, at last, are numerous and great! Of the essential difference of figure, both as to the _beams_ of the Sun, and the _beams_ of the Aurora, in severalty, and of the inevitable difference of indication of which, as to their nature, mention has been already made; and also as to the general or collective figure of the beams of the Aurora, as contrasted with that of the rising, or of the setting Sun. The next point is the homogeneity of colour in the beams of the Sun, however the apparent colour may vary, as it is seen to do, from horizontal stratum to horizontal stratum, from the horizon to the zenith, according to the varied density of the medium between the light and the eye of the spectator. The light, upon the other hand, of the beams of the Aurora is heterogeneously coloured in itself, and is so displayed; and not, therefore, varied as the beams ascend from horizontal stratum to horizontal stratum, or as crossing all the beams together, but found in each particular beam itself, and attending its direction, whether vertical or inclined, and whether rectilinear or curved. Waiving, then, any comparison in detail, between the phenomena of the Aurora, and the phenomena of the rising or of the setting Sun, but admitting that, to a certain degree, all are alike vast in dimensions, splendid in light, rich in colour, and durable upon the eye; there is still nothing else to be subjoined, than that, at least with reference to vastness of dimension and magnitude of the volume of light; to the quantity of light diffused; and to the richness and gorgeousness of [p421] the attendant colouring; there can be little risk, in the assertion that, vast, and splendid, and beautiful, and rich, and gorgeous, as, when seen in the most favourable situation, and under the most favourable circumstances, the Aurora may be, it is, at last, but insignificant, when compared, for those features, to the vastness, the splendour, the beauty, the richness, and the gorgeousness, more or less, from day to day, displayed in the rising or the setting of the Sun; and, that for chaster beauty, and even for amount of light diffused, it is not even to be likened to the silver Moon! As a substitute, too, for either, or for both, the Aurora, in the regions of cold and night, may justly demand the admiration and the blessing of mankind; and, in regions cold and inclement, its rarity, not unaccompanied by beauty, by grandeur, and sometimes even by the terrible in appearance, may well invite the gaze and fix the attention of beholders; but, considered along with the light of the luminaries of heaven, its claims reduce themselves in quality, though certainly not in degree, to a level with those of an artificial lustre; and we almost repeat, in reference to the light of the Aurora, as compared with that of the Sun, or even of the Moon, what the poet has said in reference to the lights of our chambers:—

“Who but rather turns To heaven’s broad beam his unconstrained eye, Than to the glimmering of a waxen flame?”

The Moon, in the meantime, inferior as she is to the Sun, has been “blessed,” from age to age, for her “useful light;” and the “useful light” of the Aurora, also, has its claims to “blessing.” It co-operates with the Sun, the Moon, and with other agents of nature, to make, not merely the Polar regions of the earth, but the entire globe of the earth, fruitful, at once, and habitable[127]! [p422]

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XII. In a succeeding paper, the author may possibly submit to the consideration of his reader, the particular and novel hypotheses which he has allowed himself to form, as to the _substance_, _causes_, and _effects_ of the Aurora; hypotheses partly dependent upon those _facts in its natural history_, which, above, have been almost the exclusive objects of attention. At present, the leading particulars of the _natural history_ of the phenomenon, which it has been attempted either to bring or to fix in view, are these:

1. That the Aurora is a phenomenon observed both in the Northern and Southern Hemispheres.

2. That, in either hemisphere, it is observed in the general direction of the corresponding _pole of the earth_.