Aurora

THE remarkable aurora borealis observed by Prof. Piazzi Smyth at Edinburgh on July 27 (NATURE, vol. xxxiv. p. 312) seems to have been visible over a very great area. In my meteorological journal it is remarked on July 27 that the bright silver-clouds appeared beautiful between 9.30 and 11 p.m. ``The colour of the northern sky above the silver-clouds was misty and brownish, though not cloudy.'' I had never seen such a tint in the sky. I have no hesitation in saying that the unusual darkness was the same as observed at Edinburgh. The fair white arc I did not see; clouds came up at midnight. It may be interesting to state that I also saw, on July 26 at 9.30 p.m., an aurora-like white cloud in the north-west. This cloud was very different from the well-known silver-clouds so often described in 1885 and1886. On the 28th and 29th nothing extraordinary is mentioned in my journal, but on the 30th faint traces of the silver-clouds and again ``a very strange yellow-brownish colour of the north and north-west sky'' are remarked. The great aurora on March 30 we also observed very well at Königsberg.