On the nature and origin of the Aurora Borealis

Abstract

The author deduces from.his own observations made during a residence of two winters in high northern latitudes, taken in con­junction with the concurring testimony of various navigators and tra­vellers, the general fact that the Aurora Borealis is developed chiefly at the edge of the Frozen Sea, or wherever there is a vast accumu­lation of ice; and he conceives that it is produced in situations where the vapours of a humid atmosphere are undergoing rapid congelation. Under these circumstances, when viewed from a distance, it is seen fringing the upper border of the dark clouds, termed the “sea blink,” which collect over these places; and it generally forms an arch a few degrees above the horizon, shooting out vertical columns of pale yellow light. He concludes that the Aurora Borealis is an electrical phenomenon, arising from the positive electricity of the atmosphere, developed by the rapid condensation of the vapour in the act of freezing, and the induced negative electricity of the surrounding portions of the atmosphere; and that it is the immediate consequence of the restoration of the electrical equilibrium by the intervention of the frozen particles, which being imperfect conductors, become lumi­nous while transmitting this electricity. In tropical and temperate climates this phenomenon does not occur, because the electric equi­librium is restored by means of aqueous vapours, a process which often gives rise to thunder and lightning, but never to the Aurora Borealis; the latter being peculiar to clear, cold and dry weather.