PHILOSOPHICAL INSTITUTE OF CANTERBURY.

Kumara Times, Issue 2350, 10 March 1884, Page 3

PHILOSOPHICAL INSTITUTE OF CANTERBURY.

EARTHQUAKES AND THE COLD SUMMER. At the ordinary meeting of the session of the Philosophical Institute of Canterbury, held at the Rooms of the Institute at the Public Library, Christchurch, on Thursday last, Mr E. W. Fereday in the chair, the Press reports : —■ Professor Hutton gave an address on Earthquakes. These he defined as tremors of the earth, produced by natural causes, and explained what actually occurs in the earth in such a tremor. The destructive power of an earthquake is not greatest just above the centre of impulse, but at points on the earth’s surface bearing 50 deg. from the vertical. Cuttings and buildings supported only on one side suffer most from earthquakes. In South America people get into mines for safety on this account, when shocks are expected, the mine being too small a hole to cause any appreciable lack of solidity in the ground. Earthquake waves, the Professor said, are caused by movements of land under the sea, the surface of which is but slightly raised, yet over so large an area that a wave of immense force is raised, and this meeting a shelving beach, sometimes rises to a terrific height. In 18GS an earthquake in Africa caused a wave which rolled on to New Zealand 30ft. high in some places yet on mid-ocean coral beaches the tide only rose one or two feet. Of earthquake causes we know very little, but Professor Hutton expressed himself confident that Christchurch had nothing to fear on the subject, and put forward some interesting evidence in support of his view. Mr A. Ringwood gave an interesting explanation of the rosy sunsets, he attributes them to the presence in the upper air of dust from the Krakatoa eruption. A German professor estimates this to have been thrown forty miles high—far above the atmospheric currents, though these are 50,000 ft. high at the equator. This of Krakatoa was probably the greatest explosion that had occuared since the appearance of man on the earth. The cloud of dust was so dense that to it must, in his opinion, be attributed to the present cold summer, for it would intercept as much heat as a like quantity of aqueous vapour. Messrs, Hogben, Inglis, and Dobson, and Dr. Bakewell criticised the positions taken up, and Professor Hutton and Mr Ringwood afterwards replied.