THE ever-changing form, and the faintness, of the aurora render this phenomenon a difficult subject to the photographer. Many have been the attempts to secure photographs of what have appeared to be brilliant displays, but the results have shown that little or no action had taken place on the photographic film, in spite of the fact that very rapid plates had been used. Herr Tromholt, who made a special study of the photography of the auroræ, exposed very rapid plates to what he considered bright auroræ, and even with exposures from 4–7 minutes secured no trace of them. Later, at Christiania, he was more fortunate, and obtained an impression with an exposure of 8.5 minutes. To advance our knowledge of the changes in form of this phenomenon, it is important that photographs should be secured, if possible, in a few seconds, and not minutes. This seems now to be feasible, judging from an interesting account given in the Meteorologische Zeitschrift (Heft 6, 1900), by Herr O. Baschin. Herren Brendel and Baschin stayed several months, during the winter of 1891–92, at Bossekop, in Norwegian Lappland, to study the magnetic elements and the aurora.