Aurora

Abstract

AN aurora of considerable proportions and of the radiant form was visible here on Wednesday night. At 9 p.m. the centre of energy was in the north-west, and from a large blunted cone-shaped smoke-like luminous mass in that quarter, fan-rayed streamers were projected to the zenith. The streamers were crossed at equal intervals by horizontal bars, similar in appearance, minus the motion, to the pulsating bars which sometimes form a feature of auroral activity. The day had been finer than has been the prevalent weather of late. Set of wind during the day, north-west. Drift of the clouds at high altitudes from south-west. The night calm, barometer high, thermometer 57. At 9 p.m. the western sky was covered with flocculent cirri. The north-west was obscured by the dense eruptive volume of auroral vapour. The northern sky was clear, and so was the eastern. The moon was shining brightly. The line between the auroral mass and the region of blue sky was remarkably sharp and well defined. Just after 10 p. m. a narrow streamer of great brilliancy shot from the north-west across the zenith to the north-western limb of the moon, constituting a notable feature of the display. As the night wore on, the centre of energy, together with the basal eruptive mass, travelled slowly north-wards, and the northern sky became covered with bright white beams, rays, and streamers. At the same time, clouds of the cirrus type made a mackerel sky in the west, as well as in the zenith towards the south. Some of the streamers were of extreme tenuity, others were dense and bright, hiding the stars over which they passed. The sky in the end was covered with a light haze, which condensed into a cloud canopy. No prismatic colours were visible, streamers, beams, and rays throughout being alike of a pure white light, though greatly luminous, so as to retain distinctive individuality in the face of brilliant moonlight. Thursday, early morn, sun shining through a hazy sky, wind light from the south; 9 a.m., overcast; 11 a.m., rainfall set in. Continuous all the day. Sharp fall of barometer. Thermometer mid-day, 65, wind inclined to back to the eastward. Considering that the vernal and autumnal equinoxes are the usual periods of auroral activity, and that there is yet a month to the 21st of September, an instance, now of auroral energy is somewhat out of the usual course of things. The equinoctial gales, yet earlier, set in with much rigour. Perhaps, as everything has a meaning, these phenomena presage the kind of weather which is to rule the autumn. Scarcely a summer bird remains save the swallow and martin. The swift left early. A solitary bird or a pair was observed, however, evening by evening up to the 28th to return to the nesting place of the tribe, as loth to leave the English home. To day (Friday) continuous rain, which has prevailed all the night. Mid-day, thermometer 64; barometer 29.3; set of wind southerly.