Notes

Abstract

PROF. HILDEBRAND HILDEBRANDSSON has published in the “Transactions” of the Royal Society of Sciences at Upsal, a clear and interesting account of a tornado which occurred near Hallsberg, in the province of Nerike, Sweden, on the 18th August, 1875. From the full details he gives it is evident that it closely resembled the tornadoes which have been described by the American meteorologists and the well-known tornado of Chatenay of 18th June, 1839, described by Peltier. Upwards of 1,000 large trees (Pinus abies), covering a space 1,000 feet in length by 500 feet in breadth, were totally destroyed, the greater number being torn up by the roots, whilst those about the margins of the path of the tornado were snapped across. On emerging from the forest, where its course had been directed to N.N.E., it turned in the direction of N.E., uprooting trees, overturning solid buildings, and carrying the dèbris of the ruins, in some cases, many miles from the scene of destruction. From the positions of objects thrown down, which are shown on a map, Dr. Hilde-brandsson points out that in this instance the destructive force was compounded of two forces, one being directed towards the centre of the tornado and the other in the line of its course. The true theory of these terrible phenomena can only be arrived at by such carefully observed and collated facts as Dr. Hilde-brandsson here presents us with; and much light would be thrown on this difficult question if barometric and thermometric observations were made within and near the district swept by the tornado.