merry dancers, and are thus described: 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. They often cover the whole hemisphere, and then make the most brilliant appearance.

Their mo

tions at these times are amazingly quick, and they astonish the spectator with the rapid change of their form. They often put on the colour of blood, and make a most dreadful appearance.'*

The aurora is said, in the colder latitudes, to be attended with a peculiar hissing noise. Gmelin mentions this very distinctly and positively in the interesting account which he gives of it, as it appears in Siberia. These northern lights,' says he, begin with single bright pillars, rising in the north, and almost at the same time in the north-east, which, gradually increasing, comprehend a large space of 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, and 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 painted; but, whoever should see such a northern light for the first time, could not behold it without terror; for however fine the illumination may be, it is attended, as I have learned from the relation of many persons, with such a hissing, cracking, 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 raging host is passing. The hunters who pursue the white and blue foxes, in the confines of the Icy Sea, are often overtaken in their course by these northern lights. Their dogs are then so much

* Encyclopædia Britannica, article Aurora Borealis.

frightened, that they will not move, but lie obstinately on the ground till the noise has passed. Commonly clear and calm weather follows this kind of northern lights. I have heard this account, not from one person only, but confirmed by the uniform testimony of many, who have spent part of several years in these very northern regions, and inhabited different countries, from the Yenesei to the Lena; so that no doubt of its truth can remain.'

In Captain Franklin's narrative of his journey to the Polar Sea, there are some scientific observations on the phenomena of the Aurora, which throw considerable light on this curious and interesting subject. The meteor is usually conceived to have its place very high above the earth; but exceedingly different elevations have been assigned to it by different philosophers. Euler supposed it to be some thousands of miles distant, others have fixed its place at a few hundred miles, and others again much lower. The diffused nature of the appearance in this country, renders it difficult to make any accurate observation on the subject; but if the Aurora should continue occasionally to assume the form of a moveable luminous arch, gliding slowly in a well-defined continuous body towards the zenith, as it has lately done in several instances and in different seasons, observations taken from various stations might settle the point. Be this as it may, and however high the northern lights may actually rise in this comparatively southern latitude, it seems to be ascertained by Captain Franklin and his companions, that, in the higher latitudes of North America, and still nearer the Pole, the region of the Aurora is not many miles above the earth. They discovered, by actual observation, that, in several instances, it did not rise higher than six or seven miles; and both there and in Siberia, it would seem to be often much lower even than this. The same kind of appearances as are described by Gmelin, above quoted, appear sometimes to occur on the other side of the Atlantic. These, however, are not frequent; and the more usual phenomena partake

much of the nature of the following, which I quote from Mr. Richardson's interesting observations on this meteor :

'When the Aurora had exhibited itself in this form for a considerable space of time, the whole mass of light suddenly appeared in motion, and, sweeping round on each side, was gathered together to the southward of the zenith. Immediately thereafter, a large portion of it was seen in the S. E., assuming an exact resemblance to a curtain suspended in a circular form in the air, and hanging perpendicularly to the earth's surface. The lower edge of this curtain was very luminous, and had a waving motion; and the illusion was farther heightened by the momentary appearance of perpendicular dark lines or breaks in the light, in rapid succession round the circle, exactly as the waving of a curtain would cause the dark shades of its folds to move along it. This beautiful curtain of light was about 40° high, and of a pale yellowish colour, and sent forth on the one side a process which approached the S.E. by E. point of the horizon, and the other was connected with a long regular arch, terminating in the N.W. horizon, similarly constructed, and having the same waving motion with the curtain itself. All this time the sky was perfectly clear, except in the southern quarter, which, to the height of 4° or 5°, was occupied by dark clouds, apparently intermediate between stratus and cirro

stratus.

'Half an hour after its first appearance, this curtain-formed Aurora was resolved into a number of detached irregular portions, which sometimes increased rapidly in every direction, until they met with other masses, either before existing, or appearing at the instant, and formed an uniform sheet of light, which covered the whole sky. The formation of this great sheet of light was so rapid, that the eye could only trace its progress partially; and its dissolution and reappear. ance were equally sudden.**

* Franklin's Narrative, p. 621.

SECOND WEEK-WEDNESDAY.

METEORIC SHOWERS.

I HAVE now to mention another celestial phenomenon of a very singular nature, connected with two days in the present week, which has lately attracted the attention of the scientific world. The following account of it I extract from Mrs. Somerville's 'Connexion of the Physical Sciences.'

'On the morning of the 12th of November, 1799, thousands of shooting stars, mixed with large meteors, illuminated the heavens for many hours, over the whole continent of America, from Brazil to Labrador; they extended to Greenland, and even Germany. Meteoric showers were seen off the coast of Spain, and in the Ohio country, on the morning of 13th November, 1831; and during many hours, on the morning of 13th November, 1832, prodigious multitudes of shooting stars and meteors fell at Mocha, on the Red Sea, in the Atlantic, in Switzerland, and at many places in England. But by much the most splendid meteoric shower on record, began at 9 o'clock in the evening of 12th November, 1833, and lasted till sunrise next morning. It extended from Niagara and the northern lakes of America, to the south of Jamaica, and from 61° of longitude in the Atlantic, to 100° of longitude in Central Mexico. Shooting stars and meteors, of the apparent size of Jupiter, Venus, and even the full moon, darted in myriads toward the horizon, as if all the stars in the heavens had started from their spheres. They are described as having been as frequent as flakes of snow in a snow-storm, and to have been seen with equal brilliancy over the greater part of the continent of North America.

* The French Academy of Sciences have taken an interest in the discussion to which this phenomenon has given rise, and it appears, from the recent communication of M. L. Ekberte, that the meteoric shower of 13th November, 1832, extended even to the Mauritius, where it is said to have been seen at the same period, and with the same appearances, as in other parts of the world.-Note to Third Edition, December, 1837.

'Those who witnessed this grand spectacle, were surprised to see that every one of the luminous bodies without excep tion, moved in lines, which converged in one point in the heavens; none of them started from that point; but their paths, when traced backwards, met in it, like rays in a focus, and the measure of their fall showed that they descended from it in nearly parallel straight lines towards the earth.

By far the most extraordinary part of the whole phenomenon is, that this radiant point was observed to remain stationary near the star y Leonis, for more than two hours and a half, which proved the source of the meteoric shower to be altogether independent of the earth's rotation, and its parallax showed it to be far above the atmosphere.

'As a body could not be actually at rest in that position, the group must either have been moving round the earth or the sun. Had it been moving round the earth, the course of the meteors would have been tangential to its surface, whereas they fell almost perpendicularly, so that the earth, in its annual revolution, must have met with the group. The bodies that were nearest, must have been attracted towards the earth by its gravity; and as they were estimated to move at the rate of fourteen miles in a second, they must have taken fire on entering our atmosphere, and have been consumed in their passage through it.

'As all the circumstances of the phenomenon were similar, on the same day, and during the same hours, in 1832, and as extraordinary flights of shooting stars were seen at many places, both in Europe and America, on 13th November, 1834, tending also from a fixed point in the constellation Leo, it has been conjectured, with much apparent probability, that this group of bodies performs its revolution round the sun in a period of about 182 days, in an elliptical orbit, whose major axis is 119,000,000 of miles; and that its aphelion distance, where it comes in contact with the earth's atmosphere, is about 95,000 000 of miles, or nearly the same with the mean distance of the earth from the sun."

* Mrs. Somerville on the Physical Sciences, pp. 404, 405.