Appendix C.

EXTRACTS FROM PARLIAMENTARY BLUE BOOK, CONTAINING THE “RESULTS DERIVED FROM THE ARCTIC EXPEDITION 1875-76.” (Eyre and Spottiswoode, 1878.)

Auroras observed 1875-1876, at Floebery Beach and Discovery Bay.

By Lieutenant A. C. PARR, R.N.

Though the auroral glow was often present, and served in some degree to lighten the darkness of the sky during the long winter, when the moon was absent, the actual appearances of the Aurora itself were few, and the nimbus worthy of any particular remark extremely small. Those which were stationary assumed the form of low arches, with streamers flashing up to them from the horizon, and usually to the eastward. But the more common form was for an arch to appear low down in some part of the sky where the glow was brightest; at first it was very faint and narrow, but as it rose gradually in the heavens it would increase both in size and intensity, till on arriving near the zenith, with its ends extending nearly to the horizon, it would be about the breadth of three or four rainbows, and its colour that of white fleecy clouds lit up by the rays of the full moon. On reaching this point, however, its course was nearly run; for after appearing to remain stationary, as little white gaps would suddenly rend the arch asunder, the portions thus detached seemed to roll together and concentrate all their brightness in the smaller space, and then gradually fade away and become extinct. Sometimes a very pale green would show itself in the more luminous patches, and once or twice there was a slight suspicion of red; but never was the whole sky illuminated by streams running in all directions, and forming coronæ, while these colours varied every moment.

When instead of the arch rising up from the horizon a streamer appeared, its origin was in the north. From the northern horizon it would stretch out towards the zenith, passing nearly overhead, and reaching to within a few degrees of the land to the south. In appearance they would be the same as the arches, but sometimes a second would grow out of the first, and on one occasion three were visible at the same time. They had lateral motion either from east to west, or west to east, but there was no flashing to brighten them, and they gradually faded away.

The time at which Auroras usually occurred was between 9 P.M. and midnight, the last display being on February 19th, commencing at 11 P.M. It was a beautifully clear night, without mist or haze of any description, and small stars visible close down to the horizon. At the above-named hour two arches made their appearance, and remained stationary; the lower one was the brighter, being of a pale green colour, its centre bearing E.S.E. (true), and having an altitude of about 5°, with a breadth of about twice that of a rainbow. The second arch was concentric with the first, and about 7° above it, but rather broader and fainter. These arches maintained their altitude, the upper one at about the same intensity, but that of the lower one varied considerably. It would gradually lighten up, then send flashes to the upper one, then break up and fade away; before, however, it had quite disappeared, flashes would come up to it from the horizon which seemed to endue it with new life, for the arch would be reformed, brighten up, and the same performance would be again repeated. This occurred three or four times in the course of three quarters of an hour; but the flashes from the horizon never extended beyond the lower arch, and those from the lower never went beyond the upper. During this display the citron-line was obtained very clearly with the spectroscope, but no other lines were visible.

On six or seven occasions Auroras were visible at the same time on board both the ‘Alert’ and ‘Discovery;’ but the absence of characteristic features makes it impossible to determine whether they were the same display, or merely two distinct ones which happened to occur at the same time. But as by far the larger number of those recorded in the one ship were not visible at the other, it was certainly only under exceptional conditions that they could be simultaneously observed at both stations, if, indeed, they ever were. Auroras seemed to appear indifferently both when there was wind and when it was calm, with either a high or low barometer, and seemed quite unconnected with the temperature, although on an occasion the thermometer was observed to fall 3° during the display, and to rise 2° almost immediately afterwards. But it was never seen illuminating the edges of clouds, as we saw it on the passage home, nor playing about the outline of the land, and never was there the slightest suspicion of sound being produced by it.

The opportunities for observing the spectrum of the Aurora in this position have been most unsatisfactory, as the displays were small in number and deficient in brilliancy.

The form they generally assumed was to rise like an arch from a portion of the horizon where there was a luminous glow, at first very faint, but gradually increasing in brilliancy till near the zenith, where it would remain stationary for a short time and then break up and disappear. Sometimes they would rise up as streamers, but only occasionally was more than one visible at a time, and they lasted for such a short time, that even if they had been bright it would have been very difficult to make satisfactory observations.

Very few showed any signs of colour, and those only the slightest tinge. Nearly all that were observed gave the citron-line with the small pocket spectroscope with more or less distinctness, though no signs of any other lines were ever seen; but on only two occasions was it bright enough to get the line with Nury’s spectroscope, and then only for such a short time that a satisfactory measure could not be obtained.

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Then follows a descriptive list of the Auroræ seen, from which I have selected three of the finest, viz. January 2nd, February 14th, and February 19th, 1876.

January 2nd, 1876. Lieut. Parr. Floeberg Beach.—9 P.M. Streams of Aurora. Stars shining brightly.

Register. Discovery Bay.—9 P.M. Observed an Aurora like a pale band of light in the form of an arch whose centre was on the true meridian and 15° from the zenith. It shortly afterwards broke up into feathered edges, their direction being a little to the eastward of the zenith. The arch grew fainter, and shifted to the eastward of the meridian four points; the left extremity of the arch faded away, and the right assumed the shape of the folds of a curtain doubled over. The weather was clear and calm. The display lasted upwards of 30 minutes.

A spectroscope, one of Browning’s 8-in. direct-vision, was directed towards the Aurora, but the light was not sufficient to give any spectrum.

The temperature was -39°. Barometer 29·56 inches. No wind. Clouds stratus 2. Eight meteors were observed during the time the Aurora was visible.

February 14th. Register. Discovery Bay.—At 2 A.M. a faint Aurora passing across the heavens from S.E. to S.W. was observed, like an arch of a pale colour. It lasted only a short time, and was very indistinct. Temperature -47°. Barometer 30·44 inches. No wind or clouds.

Lieut. Aldrich. Floeberg Beach.—2 A.M. A faint Aurora towards the S.W. Weather calm. Cumulus-stratus clouds 3. Temperature -46°. 8 P.M. Faint flashes of Aurora in the E. and S.W.

Lieut. Aldrich and Lieut. Parr. Floeberg Beach.—11.50 P.M. A moderately bright arch of Aurora extended from due N. to about S.S.W., where it terminated close down to the horizon in a crook turned to the eastward. In a few moments a streamer flashed from the end of the crook parallel to the first and right across the heavens, its edges being quite sharp and parallel to each other. A third streamer shot up a minute afterwards, but did not extend more than 80° upwards. The streamers were visible for a very short time, the first remaining longest. The second-named arch gradually faded away till within a few degrees of the S.S.W. horizon, and (still being a continuation of the crook) bent round to the eastward, and towards the horizon, going on to what was left of the stump of the third arc. A lateral motion to the eastward now began, the whole body gradually turning round until it disappeared about due south. Stars were visible through it at its brightest, but not very distinctly. This is the most intense and variegated Aurora we have experienced, but scarcely any colours were to be seen. Temperature -51°. Barometer 30·43 inches, stationary. Calm weather. Clouds cumulus 1. Preceded and followed by calm weather.

Meteorological Register. Discovery Bay.—9.15 P.M. An Aurora was observed to the southward, spreading out like a fan in separate ways. It was faint. A few cirro-stratus clouds were visible, apparently between the observer and the Aurora. It lasted about 40 minutes, and then gradually faded away. Temperature -47°. Barometer 30·51 inches, stationary. No wind. Clouds cirro-stratus 4.

February 19th. Meteorological Report. Discovery Bay.—9.45 P.M. An Aurora like a fluted arch, with rays flashing towards the Pole, was observed spanning the hills from the south to the east. The direction of the lines of light from all parts of the arch was towards the zenith. Above the arch a pale band of colour appeared, like a secondary arch above the other. It appeared very much as if it was caused by the reflected light of the Aurora. The Aurora was bright for a few seconds, and then gradually died away. It lasted altogether about 30 minutes. The centre of the arch bore S.E., having an altitude of about 30°. The secondary arch was about 15° above the former. Both arches were of a pale light colour, the upper one very faint. Temperature -34°. Barometer 29·87 inches, rising rapidly. Weather calm. Misty. No clouds.

Lieut. Parr. Floeberg Beach.—An Aurora appeared shortly after 11 P.M., consisting of bright arch, whose centre bore about E.S.E., and had an altitude of about 5°, with a second broader and fainter arch about 7° above the first. These arches maintained their altitudes, the upper one at about the same intensity, but that of the lower one varied considerably. It would gradually brighten up, then send streamers up to the second, then break up into light patches, and gradually fade away. This happened three or four times during the 40 minutes that the display lasted. At times streamers would come up from the horizon to the lower arch, for it was a splendidly clear night, and seemed to brighten it up, but none of them extended beyond it. Neither did the streamers from the lower arch extend beyond the upper one. It was slightly green in colour when brightest, and the citron-line was well defined, but no others were visible. Temperature -46°. Barometer 29·95 inches, steady. Weather calm. Cumulus clouds 4. Misty.

TABLE of DATES when AURORAS were observed by the ARCTIC EXPEDITION, 1875-76.

----------------+--------------------------+----------------------- | H.M.S. ‘Alert,’ | H.M.S. ‘Discovery,’ Date. | Floeberg Beach. | Discovery Bay. ----------------+--------------------------+----------------------- 1875, October 25| 11.45 P.M. Faint. | Cloudy. ” ” 26| 10 P.M. Very faint. | 10 P.M. ” ” 30| Sky obscured. Faint. | Ditto. ” November 1| Ditto. Faint, but well | | marked. | Ditto. ” ” 2| 9 to 10 P.M. Arches and | | streamers. | A few clouds. ” ” 21| Ditto. Bright | 9 to 10 P.M. | streamer. | and 10 to 11 P.M. ” ” 22| 2 P.M. and 8 P.M. Slight,| | red. | Clear sky. ” ” 25| 9.30 A.M. Character not | | recorded. | Ditto. ” ” 26| 10 A.M. Stream of light.}| A few clouds. ” ” 26| Cloudy to 10 P.M., }| | bright afterwards. }| 10 P.M. ” ” 27| Midnight. Slight. | 11.40 P.M. ” ” 28| 1 A.M. Bright streak. | Clear sky. ” ” 29| Cloudy, brighter at 11 | | A.M. Faint glow. | 9.30 A.M. ” ” 30| A few clouds. Very faint.| 4.30 A.M. ” ” 30| 5 P.M., 8 P.M., and 10 | | P.M. Flashes. | 5 P.M. ” December 2| Evening. Streamers. | Clear sky. ” ” 3| 1 A.M. Flashes. | Ditto. ” ” 3| Bright sky. Faint Aurora.| 2.30 P.M. ” ” 16| 10 P.M. Slight; showed | | citron-line. | 11 P.M. ” ” 19| 3 P.M. to 5 P.M., faint; | | and 9 to 10 P.M., | Very clear sky. | moderately bright arc. | ” ” 22| 10 P.M. Slight. | Ditto. ” ” 23| 6 P.M. Ditto. | Ditto. ” ” 24| Misty, a few stars | | visible. Arch. | 9 A.M. ” ” 26| Very bright sky. Faint. | 6 P.M. ” ” 29| Ditto. Very faint. | 6.15 P.M. ” ” 31| 4 P.M. Same. | Sky obscured. 1876, January 1| 5 P.M. and 11 P.M. | | Slight. | A few clouds. ” ” 2| 9 P.M. Described and | | figured. | 9 P.M. ” ” 17| Very bright sky. Very | | faint streamers. | 9.25 A.M. ” ” 18| 9.45 P.M. and 10.5 P.M. | | Character not recorded. | 10.15 P.M. ” ” 19| Very bright sky. Faint. | 9.45 P.M. ” ” 20| 2 A.M. Slight. | 2.30 A.M. ” ” 23| 7.55 A.M. and 2 P.M. | | Slight. | 8.45 P.M. ” ” 24| Bright sky. Slight flash.| 2 A.M. ” ” 24| 5 P.M. and 11.15 P.M. | | Faint Aurora. | Very clear sky. ” ” 27| 2 A.M. to 3.45 A.M. | | Faint. | 1 A.M. to 4 A.M. ” ” 27| Very bright sky. Faint | | double arch. | 8.30 P.M. ” ” 28| 6 P.M. and 7 to 9 P.M. | | Faint flashes. | 7.20 P.M. ” ” 30| 8 P.M. Streak. | 7.50 to 9 P.M. ” ” 31| 8.30 A.M. and 7.30 | | P.M. Very faint. | 8.25 A.M., 5.30 P.M. ” February 3| 10 P.M. Slight flash. | Very clear sky. ” ” 11| Sky obscured. Very faint.| 11 P.M. ” ” 13| 11 P.M. Flashes. | Clear sky. ” ” 14| 2 A.M., 9.15 to 10 P.M. | | Described and figured. | 2 A.M. and 11.50 P.M. ” ” 19| 9.45 P.M. | 11 P.M. ” ” 20| 2 A.M. Very faint. | 2.30 A.M. ” ” 22| 2 A.M. Character not | | recorded. | Very clear sky. ” ” 24| Bright sky. Very faint. | Midnight. ” ” 26| 10 P.M. and 11 P.M. | | Faint flashes. | Sky obscured. ----------------+--------------------------+-----------------------

I have added to the above Table the character of the Aurora in each instance as taken from the fuller descriptions given.—J. R. C.

Auroras and Magnetic Disturbances.

The appearances of Auroras and the synchronous movements of the declinometer-magnet were subjects of special observation during the stay of the ‘Alert’ and ‘Discovery’ at their winter-quarters. The Table on page 187 gives the dates and hours when Auroras were visible. On all occasions they were observed to be faint, with none of those brilliant manifestations which are described by our own officers as seen at Point Barrow, and by the Austro-Hungarian Expedition at Franz-Josef Land, where the magnetical instruments were so sensibly disturbed.

These phenomena were not observed either in the ‘Alert’ or the ‘Discovery,’ especially no connexion between magnetical disturbances and the appearances of Auroras could be traced.

This is quite in accordance with the remarks of previous observers within the region comprehended between the meridians of 60° and 90° west, and north of the parallel of 73° north. For example:—

In the Phil. Trans. 1826, Part IV. p. 76, Capt. Parry and Lieut. Foster remark, in the discussion of their magnetical observations at Port Bowen:—“As far, however, as our own observations extended, we have reason to believe that on no occasion were the needles in the slightest degree affected by Aurora, meteors, or any other perceptible atmospheric phenomenon.”

Again, in the Smithsonian Contributions, vol. x., 1858, Mr. A. Schott, in his discussion of Dr. Kane’s observations at Van Rensselaer Harbour, in 1854, remarks—“In conformity with the supposed periodicity of this phenomenon as recognized by Professor Olmstead, no brilliant and complete Auroras have been seen; with an exception of very few, they may all be placed in his fourth class, to which the most simple forms of appearances have been referred.” The following statement is given in the same page as a footnote:—“The processes have no apparent connexion with the magnetic dip, and in no case did the needle of our unifilar indicate disturbance.”

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The following description of the Aurora observed on 21st November, 1875, is given by Commander Markham and Lieut. Giffard, in their abstract of observations at Floeberg Beach:—

“Between 10 and 11 P.M. bright broad streamers of the Aurora appeared 10° or 15° above the north horizon, stretching through the zenith, and terminating in an irregular curve about 25° above the south horizon, bearing S.S.W. During the Aurora’s greatest brilliancy the magnet was observed during five minutes to be undisturbed.”