What is the origin of these remarkable phenomena? The ancients asked the question, and the moderns reply by repeating it. Before proceeding to describe the magnificent auroral displays of August 28th and September 2d, let us examine authorities upon this subject, and see if we cannot arrive at some satisfactory solution of the phenomena. The following is the description given by Humboldt in "Cosmos" :

"An aurora borealis is always preceded by the formation in the horizon of a sort of nebulous veil, which slowly ascends to a height of 4°, 6°, 8°, and even to 10°. It is towards the magnetic meridian of the place that the sky, at first pure, begins to get brownish. Through this obscure segment, the color of which passes from brown to violet, the stars are seen, as through a thick fog. A wider arc, but one of brilliant light, at first white, then yellow, bounds the dark segment. Sometimes the luminous arc appears agitated, for hours together, by a sort of effervescence, and by a continuous change of form, before the rising of the rays and columns of light, which ascend as far as the zenith. The more intense the emission of the polar light, the more vivid are its colors, which, from violet and bluish white, pass through all the intermediate shades of green and purplered. Sometimes the columns of light appear to come out of the brilliant arc mingled with blackish rays, resembling a thick smoke; sometimes they rise simultaneously from different points of the horizon, and unite themselves into a sea of flames, the magnificence of which no painting could express; for, at each instant, rapid undulations cause their form and brilliancy to vary. Motion appears to increase the visibility of the phenomena. Around the point in the heaven which corresponds to the direction of the dipping needle produced, the rays appear to meet and form the boreal coro

end of the phenomenon. The rays then become more rare, shorter, and less vividly colored. Soon nothing further is seen on the celestial vault than wide, motionless, nebulous spots, pale, or of an ashy color; they have already disappeared, when the traces of the dark segment whence the appearance originated still remain on the horizon."

The connection that seems to exist, says De la Rive, between the polar light and the appearance of a certain species of clouds is confirmed by all observers; all have affirmed that the polar light emitted its most brilliant rays when the high regions of the air contained heaps of cirri, strata of sufficient tenuity and lightness to cause a corona to arise around ́ the light. Sometimes these clouds are grouped and arranged almost like the rays of an aurora borealis; they then appear to disturb the magnetized needle. Father Secchi has remarked, that magnetic disturbances are manifested at Rome whilst the sky is veiled with clouds that are slightly phosphorescent, which, at night, present the appearance of feeble aurora boreales.

After a brilliant aurora borealis, we have been able to recognize, on the following morning, trains of clouds, which, during the night, had appeared as so many luminous rays.

The absolute height of aurora boreales has been very variously estimated by different observers. It has long been thought that we might determine it by regarding, from two places widely distant from each other, the same part of the aurora,―the corona, for example. But we have started from a very inaccurate assumption, namely, that the two observers had their eyes directed to the same point at the same time, whilst it is now well proved that the corona is an effect of perspective, due to the apparent convergence of the parallel rays situated in the magnetic meridian; so that each observer sees his own aurora borealis, as each sees his own rainbow. The aspect of the phenomenon depends also upon the positions of the observ

ers.

The seat of the aurora borealis is in the upper regions of the atmosphere; though sometimes it appears to be produced in the less elevated regions where the clouds are formed. This, at least, is what follows from some observations, especially from those of Captain Franklin, who saw an aurora borealis the light of which appeared to him to illuminate the lower surface of a stratum of clouds; whilst some twenty-five miles farther on, Mr. Kendal, who had watched the whole of the night without losing sight of the sky for a single moment, did not perceive any trace of light. Captain Parry saw an aurora borealis display itself against the side of a mountain; and we are assured that a luminous ring has sometimes been perceived upon the very surface of the sea, around the magnetic pole. Lieutenant Hood and Dr. Richardson, being placed at the distance of about forty-five miles from each other, in order to make simultaneous observations, whence they might deduce the parallax of the phenomenon, and consequently its height, were led to the conclusion that the aurora borealis had not a greater elevation than five miles. M. Liais, having had the opportunity of applying a method, which he had devised for measuring the height of aurora boreales, to an aurora seen at Cherbourg Oct. 31, 1853, found that the arc of the aurora was about two and a half miles above the ground, at its lower edge.

Various observations made by Professor Olmsted, in conjunction with Professor Twining, of New Haven, led him, on the contrary, to fix the elevation on different occasions at forty-two, one hundred, and one hundred and sixty miles. He claims that it is rarely less than seventy miles from the earth, and never more than one hundred and sixty. He also claims that its origin is cosmical, or, in other words, that the earth, in revolving in its orbit, at certain periods passes through a nebulous body, which evolves this strange light in more or less brilliancy, as the body is larger or smaller. To support this theory, he

attempted to establish that there were fixed epochs for its display in the highest degree of brilliancy. The length of these periods was from sixty to seventy years, and the next appearance was to be in 1890. The remarkable displays of August 28th and September 2d show the fallacy of his conclusions in this respect.

Mairon and Dalton had also thought that the aurora borealis was a cosmical, and not an atmospheric phenomenon. But M. Biot, who had himself had an opportunity of observing the aurora in the Shetland Isles in 1817, had already been led to recognize it as an atmospheric phenomenon, by the consideration that the arcs and the coronæ of the aurora in no way participate in the apparent motion of the stars from east to west,-a proof that they are drawn along by the rotation of the earth. Hence, almost all observers have arrived at the same conclusions; we will in particular cite MM. Lottin and Bravais, who have observed more than a hundred and forty auroræ boreales. It is therefore now clearly proved that the aurora borealis is not an extra-atmospheric phenomenon. To the proofs drawn from the appearance of the phenomenon itself we may add others deduced from certain effects which accompany it, such as the noise of crepitation, which the dwellers nearest to the pole affirm that they have heard when there is the appearance of an aurora, and the sulphurous odor that accompanies it. Finally, if the phenomena took place beyond our planet and its atmosphere, why should they take place at the polar regions only, as they often do?

to me, as I have got out of the Channel when other men as alert, and in faster ships, but unapprised of this circumstance, have not only been driven back, but with difficulty escaped shipwreck."

Colonel James Capper, the discoverer of the circular nature of storms, remarks: "As it appears, that, on all such occasions, the current of air comes in a direction diametrically opposite to that where the meteor appears, it seems probable that the aurora borealis is caused by the ascent of a considerable quantity of electric fluid in the superior regions of the atmosphere to the north and northeast, where, consequently, it causes a body of air near the earth to ascend, when another current of air will rush from the the opposite point to fill up the vacuum, and thus may produce the southerly gales which succeed the aurora borealis."

The bark "Northern Light," arrived at Boston from Africa, was at sea on the night of the great exhibition of the aurora borealis, the 28th of August. The vessel was struck by lightning twice, after which the red flames of the aurora burst upon the astonished vision of the crew. Most of them are confident that they smelt a sulphurous odor all night.

M. de Tessan, who, in the voyage of the "Venus" around the world, had the opportunity of seeing a very beautiful aurora australis, (southern aurora,) which he describes with much care, also considers that this phenomenon takes place in the atmosphere. The summit of the aurora being in the magnetic meridian, it was elevated 14° above the horizon, and the centre of the arc was on the prolongation of the dipping needle, the dip being about 68° at the place of the observation. M. de Tessan did not hear the noise arising from the aurora, which he attributes to the circumstance that he was too far distant from the place of the phenomenon; but he reports the observation of a distinguished officer of the French navy, M. Verdier, who, on the night of October 13th, 1819, being in the latitude of Newfoundland, had heard very distinctly a sort of crackling

or crepitation, when the vessel he was on board was in the midst of an aurora borealis. This was also observed in many localities during the aurora of August 28th, 1859. A New York paper, alluding to the subject, remarks: "Many imagined that they heard rushing sounds, as if Æolus had let loose the winds; others were confident that a sweeping, as if of flames, was distinctly audible." Burns, a good observer, if ever there was one, and not likely to be aware of any theories on the subject, alludes in his "Vision" to a noise accompanying the aurora, as if it were of ordinary occurrence:— "The cauld blue North was flashing forth Her lights wi' hissing eerie din."

It finds confirmation also in the fact, generally admitted by the inhabitants of the northern regions, that, when the auroræ appear low, a crackling is heard similar to that of the electric spark. The Greenlanders think that the souls of the dead are then striking against each other in the air. M. Ramm, Inspector of Forests in Norway, wrote to M. Hansteen, in 1825, that he had heard the noise, which always coincided with the appearance of the luminous jets, when, being only ten years old, he was crossing a meadow covered with snow and hoar-frost, near which no forests were in existence. Dr. Gisler, who for a long time dwelt in the North of Sweden, remarks that the matter of the aurora boreales sometimes descends so low that it touches the ground; at the summit of high mountains it produces upon the faces of travellers an effect analogous to that of the wind. Dr. Gisler adds, that he has frequently heard the noise of the aurora, and that it resembles that of a strong wind, or the hissing that certain chemical substances produce in the act of decomposition.

M. Necker, who has described a great number of aurora which he observed at the end of 1839 and at the commencement of 1840, in the Isle of Skye, never himself heard the noise in question; but he remarks that this noise had been

very frequently heard by persons charged with meteorological observations at the light-house of Swenburgh Head, at the southern extremity of Shetland. M. Necker is not the only observer who has not heard the noise; neither have MM. Lottier and Bravais, who have observed so great a number of auroræ, ever heard it; and a great many others are in this This may be due to the fact that it is necessary to be very near to the aurora in order to hear the crepitation in question, and also to the fact that it is possible that it does not always take place, at least in a manner sufficiently powerful to be heard.

case.

We have just been pointing out, as concomitant effects of the aurora borealis, a noise of crepitation analogous to that of distant discharges, and a sulphurous odor similar to that which accompanies the fall of lightning. M. Matteucci also observed at Pisa, during the appearance of a brilliant aurora borealis, decided signs of positive electricity in the air; but of all phenomena, those which invariably take place at the same time as the appearance of the aurora borealis are the magnetic effects. Magnetized needles suffer disturbances in their normal direction which cause them to deviate generally to the west first, afterwards to the east. These disturbances vary in intensity, but they never fail to take place, and are manifested even in places in which the aurora borealis is not visible. This coincidence, proved by M. Arago without any exception, during several years of observation, is such that the learned Frenchman was able, without ever having been mistaken, to detect from the bottom of the cellars of the observatory of Paris the appearance of an aurora borealis. M. Matteucci had the opportunity of observing this magnetic influence under a new and remarkable form. He saw, during the ap pearance of the aurora borealis of November 17, 1848, the soft iron armatures employed in the electric telegraph between Florence and Pisa remain attached to their electro-magnets, as if the lat

ter were powerfully magnetized, without, however, the apparatus being in action, and without the currents in the battery being set in action. This singular effect ceases with the aurora, and the telegraph, as well as the batteries, could operate anew, without having suffered any alteration. Mr. Highton also observed in England a very decided action of the aurora borealis, November 17, 1848. The magnetized needle was always driven toward the same side, even with much force. But it is in our own country that the action of the aurora upon the telegraphwires has been the most remarkable.

My attention was first called in 1847 to the probability of the aurora's producing an effect upon the wires; but, although having an excellent opportunity to observe such an effect, I was not fortunate enough to do so until the winter of 1850, and then, owing to the feeble displays of the aurora, only to a limited extent. In September, 1851, however, there was a remarkable aurora, which took complete possession of all the telegraph-lines in New England and prevented any business from being transacted during its continuance. The following winter there was another remarkable display, which occurred on the 19th of February, 1852. It was exceedingly brilliant throughout the northern portion of our continent. I extract the following account of its effects upon the wires from my journal of that date. I should premise, that the system of telegraphing used upon the wires, during the observation of February, 1852, was Bain's chemical. No batteries were kept constantly upon the line, as in the Morse and other magnetic systems. The main wire was connected directly with the chemically prepared paper on the disc, so that any atmospheric currents were recorded upon the disc with the greatest accuracy.

Our usual battery current, decomposing the salts in the paper, and uniting with the iron point of the pen wire, left a light blue mark on the white paper, or, if the current were strong, a dark one, the color of the mark de

pending upon the quantity of the current upon the wire.

Thursday, February 19, 1852. "Towards evening a heavy blue line appeared upon the paper, which gradually increased in size for the space of half a minute, when a flame of fire succeeded to the blue line, of sufficient intensity to burn through a dozen thicknesses of the moistened paper. The current then subsided as gradually as it had come on, until it entirely ceased, and was then succeeded by a negative current (which bleaches, instead of coloring, the paper). This gradually increased, in the same manner as the positive current, until it also, in turn, produced its flame of fire, and burned through many thicknesses of the prepared paper; it then subsided, again to be followed by the positive current. This state of things continued during the entire evening, and effectually prevented any business being done over the wires."

Never, however, since the establishment of the telegraphic system in this country, have the wires been so greatly affected by the aurora as upon Sunday night, the 28th of August, 1859. Through out the entire northern portion of the United States and Canada, the lines were rendered useless for all business purposes through its action. So strongly was the atmosphere charged with the electric fluid, that lines or circuits of only twelve miles in length were so seriously affected by it as to render operation difficult, and, at times, impossible.

The effects of this magnetic storm were apparent upon the wires during a considerable portion of Saturday evening, and during the whole of the next day. At 6, P. M., the line between Boston and New Bedford (sixty miles in length) could be worked only at intervals, although, of course, no signs of the aurora were apparent to the eye at that hour. The same was true of the wires running eastward through the State of Maine, as well as those to the north.

The wire between Boston and Fall River had no battery upon it Sunday, and yet there was an artificial current upon it, which increased and decreased in intensity, producing upon the electromagnets in the offices the same effect as would be produced by constantly opening and closing the circuit at intervals of half a minute. This current, which came from the aurora, was strong enough to have worked the line, although not sufficiently steady for regular use.

The current from the aurora borealis comes in waves, — light at first, then stronger, until we have, frequently, a strength of current equal to that produced by a battery of two hundred Grove cups. The waves occupy about fifteen seconds each, ordinarily, but I have known them to last a full minute; though this is

rare.

As soon as one wave passes, another, of the reverse polarity, always succeeds. I have never known this to fail, and it may be set down as an invariable rule. When the poles of the aurora are in unison with the poles of the current upon the line, its effect is to increase the current; but when they are opposed, the current from the battery is neutralized, -null. These effects were observed at times during Saturday, Saturday evening, and Sunday, but were very marked during Sunday evening.

It is hardly necessary to add here, that the effect of the aurora borealis, or magnetic storm, is totally unlike that of common or free electricity, with which the atmosphere is charged during a thunderstorm. The electricity evolved during a thunder-storm, as soon as it reaches a conductor, explodes with a spark, and becomes at once dissipated. The other, on the contrary, is of very low tension, remains upon the wires sometimes half a minute, produces magnetism, decomposes chemicals, deflects the needle, and is capable of being used for telegraphic purposes, although, of course, imperfectly.