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.
| Date. | H.M.S. ‘Alert,’ Floeberg Beach. | H.M.S. ‘Discovery,’ 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 streamer. | 9 to 10 P.M. 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. 10 P.M. |
| ” | ” | 26 | Cloudy to 10 P.M., bright afterwards. | |
| ” | ” | 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., moderately bright arc. | Very clear sky. |
| ” | ” | 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:—