Sound of the Aurora

Abstract

UNDER the above heading Mr. Ogle, in last week's NATURE (vol. xxiv. p. 5), gives an extract from the Visitors' Book at the Æggischorn Hotel describing certain electrical effects which were experienced by Mr. and Mrs. Spence Watson, Mr. Sowerby, and myself on July 10, 1863. I would add one or two facts with regard to our position and experiences. We reached the top of the Jungfrau Joch at 10.5 a.m., and were met by a violent hailstorm, which came rolling up from the northern side of the Col. We at once started to return, and had been walking for two hours down the centre of the Aletsch glacier when the electrical effects began to be felt; we reached the Mërjeltn See at 3.15, so that at the time of the occurrence we had reached the lower part of the névé which is farthest from surrounding mountain tops, where the glacier is widest. We were enveloped in cloud, above which there were no doubt other clouds charged with electricity, and as they approached we were gradually being charged more and more strongly by induction from the lower cloud, and when the discharges or thunder occurred we were suddenly relieved by an electric shock. A kind of brush discharge of gradually increasing intensity went on for some minutes, followed by a sudden shock, and this process of bringing us up to the right state of excitement, to be relieved by a sudden shock, was repeated over and over again several times.