5. About half-past eleven o’clock, or nearer to twelve, several powerful columns shot toward the zenith; while, to the east of north, others were at once curved in their form, and projected in an angle of about thirty degrees with the horizon. But while, upon the west of north, the sky, above the ridge of clouds, was entirely clear, so that, there, the columns played upon a ground which formed a slight contrast with themselves, here, the clouds were still heavy, and the columns behind them appeared, in consequence, of a fiery red, deepening as they approached the outer edge of the whole display, at which was the sharpest outline, contrasted in the distinctest manner with the dark sky. The light upon that side called to the mind of the writer the “dunnest smoke of hell,” of Macbeth; while, as to its outer line, as seen from the east end of Pall-mall, the sides of the stone spire of St. Martin’s church, which rose to the eastward of it in the sky, were not more sharply defined; the dark intervening sky affording relief to both, though not equally so, upon account of the superior brightness of even the obscured columns. But, in taking leave of this columnar, or spear-like, and main part of the Aurora, it may be permitted to add, that, in those tapering forms, together with their motions, (though the comparison [p393] may still be sufficiently remote and fanciful,) it was easy to discern the origin of their having been resembled to weapons of war; that is, to the spears of an army, raised, lowered, laid at angles, and gleaming, glittering, crossing, and clashing in battle. And equally, too, from their quick, varied, and separate, and, as it were, whimsical motions, might they reasonably receive, in their milder displays, and in moments of more peaceful and cheerful association, the very different name of merry dancers!
III. Though, as will presently be found, it is the ruling idea of the present writer, that the Aurora Borealis is a single object, its appearance, when unmodified by the accompaniments of clouds or fogs, being merely that of its own coruscations, playing in the free expanse, yet for the purposes of analytical description and contemplation, it is here thought convenient to divide it into the three parts in which, through the temporary and accidental intervention of the coloured arch before-mentioned, it appeared in the night now in recollection. These three supposititious parts, then, may be understood as follows: first, the arch, belt, or band which was temporarily thrown across the heavens; second, the main body of the coruscations below the arch; and third, the coruscations above it, and in or near the zenith. It is of these only that it remains to speak.
It was not till about midnight that the zenith itself (which, however, formed the southern boundary to this part of the display) became the scene of a class of appearances, differing, indeed, essentially, in their forms, from those in the horizon, but closely connected, as it may be believed, with all the materials, and all the movements, of these latter. The zenith, at that hour, was cloudless, and resplendent with stars, and the air was freshened by a gentle breeze from the south. Between the earth and the stars above, there was no apparent intervening vapour, and nothing, therefore, save that atmospherical fluid which eludes the sight. But, through that medium, if such only it was, coruscations were now continually shooting, of which the appearance was, that it overspread this portion of the vault of heaven with an ever-shaken [p394] sheet of thin, gauzy, white, or yellowish-white, and nebulous, or cloudy matter. To the writer, this superior portion of the Aurora, though not the most lustrous, and, therefore, not the most striking of the whole, was yet by no means the least interesting and inviting to attention; for, here, as its appeared to him, the material and the manner of operation of the meteor were brought nearer to the eye, and exhibited with such a back-ground (the starry heavens) as gave a transparent view of the same matter as that, which, (as he thought,) seen vertically, and in the horizon, appeared comparatively, at least, opaque. The transparent medium, however, above, through which, even when shook or vibrating, and even when whitened with light, the stars were always seen in more or less brightness, was now in continual motion; or, meteoric light or matter was continually, though irregularly, and as it were, playfully shot through it. The illuminated substance (whether the atmospherical fluid, reflecting the light of the meteor, or the luminous body of the meteor itself, but probably the latter) was incessantly discovering itself in different places; now here, now there, now bright, now dim; but far less in a manner, or with an appearance, such to be compared with lightning, than with such as resembled the changes of ripple upon the bosom of a wide-spread water, when a variable breeze blows over it; first in one part, and then in another; and now in one direction, and the next moment in a second. Or, the canopy of heaven, at this time, might be said to be composed of a lace or gauze bearing a figured pattern, of which the fluttering motion continually changed the places, or hid or re-displayed the figures represented; or the picture, perhaps, will be more easily imagined, if conveyed in the very appropriate language of an older hand, which, referring to the appearances displayed in the zenith, remarks, “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. This, again, is brilliantly illuminated in the same manner, and as suddenly left a dull blank.” It should be understood, however, that, at least as seen by the present writer, in this mixture of white and blue, the blue was always the preponderating colour; or, in other words, [p395] that, the field of the unoccupied zenith always bore a large proportion to the space or spaces covered, however momentarily, with light, or with the luminous substance. For the rest, the particular mentioned in the passage which has now been quoted, namely, that of the residue of a dusky track, after the departure of the white light, did not, if it was there, attract the attention of the present writer, upon the late occasion; but he certainly, in many instances, remarked the return of the light to the places in which it had been visible before; and this feature, either with or without that of the continuance of a dusky track, is possibly capable of adding some support to the general opinion which he conceived at the moment, which all subsequent information has still allowed him to retain, and of which he proposes to make further use; namely, that the appearances in the zenith are only extended exhibitions of the luminous phenomena in the horizon, or their southern extremities, or the tops of columns projected from the northward. He thought that, in the zenith, he saw the same material, parcelled out, attenuated or diluted, spread thin, and, as it were, shown with greater transparency, with that which, in thicker volume, with more accumulated strength, intenser light, with more solid body, and withal behind a denser mass of atmospherical vapour, arose, and glowed, and sometimes gloomed, in the horizon. But, be this as it may, it is, perhaps, this upper part of the exhibition, in which the lights or streamers seem to interweave, or cross and recross each other, to dance in and out of the area, and to indulge in motions still more capricious or anomalous than is probably the real fact; it is, perhaps, this upper part which has alternated, as before recalled to view, the names and similitudes of spears, gleaming, glittering, interposing and clashing as in battle, and of merry dancers, the latter the gayer comparison of the dancing north.
IV. The Aurora continued to fix the attention of the writer till between twelve and one o’clock of the morning of the 26th; and he presumes that it continued visible till the superior light of the rising day eclipsed its glory. The 26th was warm, but oppressed with fog, through which the sun broke [p396] only at intervals; and, between four and five o’clock in the evening, a small but steady rain commenced, and continued, or rather increased in heaviness, till after midnight. Between eleven and twelve, while it still rained, the writer, on looking at the sky, which was covered with a uniform mass of clouds, the writer observed, from point to point, over the northern and southern hemispheres, a glow of ruddy light, which he suspected, and still suspects, to have been produced by the light of the continued Aurora, reflected by the vapour. He took the opinion of a fellow-traveller, which coincided with his own; but it has not come to his knowledge that any individual, himself and his companion excepted, has formed a similar conjecture—nor, indeed, is it impossible that it was no more than the light of the hidden moon. The night of the 27th was star-light, though with fog near the surface; and there was then no appearance of an Aurora. The night of the 28th was remarkably clear, and there was still no return of the Aurora. The morning of the 29th was warm, with continued and heavy rain; but, after this, there succeeded a week or more of clear and dry weather; and these united particulars close the history of the phenomenon, as far as belong to the personal observation of the writer. The direction of the winds, and the state of the barometer and thermometer, were of the same general description, during many days subsequent to the appearance of the Aurora on the 25th, as that which had belonged to them from the 20th, and almost for many days before, and of which the particulars have been stated above; and these remarks may merit record, as connected with the question of the ordinary duration of the Aurora, and of the weather by which it may be thought produced, or which it may be thought to bring. In many instances, it has been observed, even in its splendour, and even in southern latitudes, for several nights in succession; and an influence upon the weather has likewise been expected from its appearance. Upon this occasion, there was no remarkable change in the latter till the night of the fourteenth day after the Aurora (October 10th), when there occurred a violent gale of wind from the south-west, accompanied with loud thunder, and the most vivid lightning; subsequently to which, as usual, [p397] the air, for a few days, was felt to be cooler than before. It has been said, that a gale of wind, from the south-west, is always to be looked for within twenty-four hours after the Aurora.
V. The astronomical writer, already more than once mentioned, speaking of the Aurora of the 25th of September, describes it as “that mysterious phenomenon;” and Mr. Adams, the meteorological correspondent of the publication referred to, records it as, “perhaps, as conspicuous as any that has ever been seen in England[122];” so that, assuming these impressions in both instances to be well founded, neither the present state of science upon the one hand, nor the specimen of the phenomenon upon the other, are such as to discourage either of the objects of the remainder of these pages; namely, the one to contribute, as fully as possible, to the completion of a faithful account of the Aurora, as seen in London upon the late occasion, by uniting, and by analysing the descriptions that have caught already the eye of the writer; and the other, to correct, and to enlarge if it should be practicable, the natural history of this description of meteor, by the comparison of what has hitherto been usually written upon the subject, either descriptively or philosophically, as well with the results of the late actual observations, as with the several facts or opinions more anciently registered. According to some, the interval which had elapsed, since an equal or a superior display of this phenomenon was witnessed in London, is twenty-four years, and, according to others, thirty-six; nor is the scanty list of examples scientifically recorded, at all inconsistent, from the wide separation, as well as irregularity of its dates, with such a view of the infrequency and uncertainty of any considerable appearance in other southern latitudes. The opportunity, therefore, now offered, ought not, perhaps, to be neglected; and the writer is not wholly without the prospect, that, upon a re-examination, both of opinions and facts, some safe and inevitable conclusions may be elicited, both as to the history and the theory of the meteor, hitherto, the one hastily received, [p398] and the other negligently overlooked, or unwarrantably contradicted. The paragraphs, then, which immediately follow, will connect and review the accounts of the writer’s fellow-observer of the 25th of September; while those which succeed will be devoted to a brief enumeration of statements already recorded in books; though, to a certain extent, both these paths will involve us in mixed investigations, historical and theoretical.
1. “It first appeared,” says Mr. Adams, who dates from Edmonton, in Middlesex, “about eight o’clock in the evening, as a strong white light, much resembling the approach of sunrise; and so continued till a short time after eleven, when a considerable number of dark clouds collected toward the north and north-west, and several streaks of a pale white light were seen proceeding from the clouds, and reaching nearly to the zenith. But the most remarkable part of the phenomenon was exhibited in a N.N.E. direction, where, at about 30° above the horizon, was a small dense cloud, above which was a broad streak curved, and about 10° in length, varying in colour from a deep copper hue to a red.” “From this,” continues Mr. Adams, “the coruscations were incessant, and remarkably bright, darting frequently to the zenith, where they were frequently crossed by others equally bright and numerous, proceeding from the west toward the east.”
2. The astronomical writer, who dates from Deptford, describes the phenomenon as commencing at a quarter past eight o’clock, and travelling, from west and north-west, to north-east; and the streaks, or streamers, or, as he denominates them, the flashes, “converging to the zenith,” and “coruscating with great velocity.” He also particularises the peculiar appearance of “a streak or column of a phosphorescent violet tinge;” and adds, “The two red beams of light, seen in the easterly and westerly direction [directions], were diametrically opposite to each other, and ninety degrees distant from the violet light (by far the most luminous, though comparatively quiescent) which was to the west of north, and therefore could not be far from the magnetic meridian, which would be crossed at right angles by a line joining the places of the red beams. The southern edges of these were accurately defined, not blending with the adjacent azure, but most distinct from it, and [p399] perpendicular to the horizon.” Finally, this gentleman speaks of the general luminous aspect, as “much resembling the tail of a comet,” and says, that Ursa Major, and other stars, were visible through its medium; that three meteoric stars also appeared, during the phenomenon, in the east and north-east; and that the entire horizon was obscured by dark, heavy clouds, from three to five degrees in height[123].