There are seldom intervals of many hours which are not illuminated by these beautiful meteors, called AurorÆ Boreales, or Northern Lights, occurring in a never-ending variety of form, colour, and intensity. They generally have a tendency to form an irregular arch, and one side of them is always much better defined than the other. The more ragged side sends out brilliant corruscations, shooting out into the sharpest angles.

Sir John Ross describes one which was nearly the colour of the full moon, and of equal brightness, in the form of a well-defined arch extending quite across the heavens, and reminded him of what he conceived must be the effect of Saturn's ring seen by the inhabitants of that planet from its surface. It lasted for several hours, and at last broke up as it were into fragments of light, and disappeared.

The distinctness of its form is much influenced by the wind, and when the air becomes agitated, showers of rays spread out in every direction with the quickness of lightning. Sir Edward Parry describes long bands of light extending with immense rapidity, but always appearing to form round a fixed point, something like a riband held in the hand and shaken with an undulatory motion.

Little scraps of the brightest light dart about in the heavens, called by the sailors, "merry dancers." In stormy weather these wild little things assume all manner of fanciful shapes; sometimes they shoot like rockets across the firmament, then take a zigzag or waving direction, and frequently seem to become invisible, and shine out again a little further on. The Esquimaux say that these appearances are the spirits of their ancestors playing at ball with the head of a Walrus! You may perhaps laugh at this odd notion, and I will laugh with you, if you will learn a lesson from it. You see that men in various states of society, are always looking out for the appearance of spiritual beings, and therefore that this disposition is a part of their constitution which is given them by God: and although their fancies may form strange notions at times, yet the exercise of the faculty, in some way or other, is very important. Men had much better think that they see spirits in the Aurora Borealis, and that they hear them in the wind, than forget that there are such things as spirits, and that they have spirits within them, which will live when their bodies are turned into dust.

But for you, my little friends, who are better instructed, there is no occasion to think you can see or hear spirits with your bodily ears and eyes; but I trust you will always feel inwardly that there are spirits within you and around you, and one Great Spirit above you.

The most beautiful form of the Aurora, is called the Corona. It is a luminous ring generally just overhead, with long distinct rays very slender, but extremely bright, diverging from it all round. It only lasts a few seconds, and then seems to burst like a firework, scattering sparks in all directions.

The stars mostly shine through the Aurora, as through a veil of thin gauze. The darkness of the sky, with the stars shining in it above and below, produces a most astonishing effect, which you may see very well represented in the frontispiece, where there is depicted a small portion of the middle of a luminous arch, very clearly defined.

It was considered, till quite lately, that the Aurora in the Northern regions, made a sort of rushing and rattling noise. This, however, seems to be false, for Captain Lyons used to stand on the ice with his ears uncovered till they were nearly frost-bitten, listening with the utmost attention, but he could never hear the slightest sound. A very intelligent Danish traveller says, that he has often heard the sound, but that he is convinced of its being produced by the wind blowing upon the ice. The reason of its being heard while the Aurora is shining, seems to be that the Aurora often appears when it is windy, or has something to do with a change of weather, which also occasions the noise.

The Aurora often appears in this country, but not with nearly so much brilliancy or frequency, as in more northern countries. I have, however, seen it very beautifully developed in light tints of red, yellow, and green, but very seldom with a clear outline and determinate form. It appears that it has been observed here much oftener than formerly, within the last hundred years, and this applies to nearly the whole of Europe, where it occurs. In Sweden, before the year 1716, it was a great rarity, and about the same time the inhabitants of Iceland were alarmed at its becoming so much more frequent than it had previously been, supposing that it portended some great misfortunes to be coming upon them. A similar fancy prevailed amongst ignorant persons in this country, and I have heard that people used to imagine that the appearance was a sign of an approaching war.

I have very little to say to you respecting the cause of this wonderful phenomenon. The most reasonable notion seems to be, that it is occasioned by electric fluid playing about, and diffusing itself in the upper regions of the atmosphere, where the air is very thin. A similar kind of light is produced by a very pretty experiment, which consists in sending an electric spark through a long glass vessel, from which the air has been exhausted. When the air is more compressed, as it is near the surface of the earth, the electric fluid does not so spread itself abroad, but moves in more direct lines, and in more compact masses, as you may see in lightning, or in the sparks of an electrifying machine sent into the atmosphere under ordinary circumstances of density.