Page from an album of auroral photographs obtained during Carl Störmer’s first expedition to Bossekop in northern Norway. It…
Page from an album of auroral photographs obtained during Carl Störmer’s first expedition to Bossekop in northern Norway. It shows a sequence of images of quiet and rayed auroral arcs, together with other less distinct forms, obtained on the night of 3-4 March 1910. The camera employed an objective lens by Ernemann of Dresden, adopted from a small children’s cine-camera, and sensitive ‘Lumière etiquette violette’ photographic plates. With such equipment, the exposure time for bright auroral forms could be reduced to half a second.