VOLCANOES.

Dominion, Volume 6, Issue 1687, 1 March 1913, Page 8

VOLCANOES.

GERMAN SCIENTIST'S VIEWS. There is a great deal to be learned vet about volcauies (fays flie "Sydney Morning Herald"). Though it lias been closely studied from Aristotle's time downwards, vuleaiiology is perhaps the most backward of all sciences, because you cannot experiment with volcanoes. You win only observe them. A variety of explanations of the action of volcanoes is offered by vulcnnologists. They are split into general camps. When they do liofc ofl'er explanations of their own they expound reasons .why tho explanations of others will not do. Professor Percival, of Freiburg' University, in Bndcn, who is on his w<y. to New Zealand, makes vuleaiiology his special hobby. He is a Professor of Gepology, "and," he said, "I am interested in volcanoes, particularly from a geological point of view. There is nioro to bo learned from volcanoes than from any. geological phenomena, because they are responsible for inoro changcs on tho sur fnce of tile earth than any other agency." Ho lias just como from Java, where he has been studying the volcanoes there, and is coming to New Zealand to spend a month or two in tho centres of thermal activity, and he will also look at tho volcano of Ngaurulioe. This will be hi 6 second visit to New Zealand. The volcanoes ill Java were, he said, in a state of quiescence, and were likely to continue so for a very long time. Volcanio eruptions were generally caused by tho pull of tho sun and moon together over the particular aTea in which they happened to be in. This was probably the cause of the eruption in Krakatoa in '1883, and of the eruption which resulted in the destruction of Pompeii. If tho sun and moon were acting together on any particular volcanic area, something_ was likely to happen that would result in the latent energy of tho volcano being Toused. Sudden and excessive generation of 6tenm when' tho hot part of the volcano came into contact with water caused the explosions. This contact might be due to various causes. The times of eruptions and earth storms could bo easily calculated by tho position of the sun and the moon, mid not only forwards but backwards as well. One could pretty accurately foretell, by astronomical calculation, when any active volcano would burst out, but "sometimes for various reasons calculations were upset. All tho volcanoes, which were the safety-valve for the earth in general, were in a moro or less direct line noj-th and .south. There could be no eruptions at any point; situated at anv distance from the region of water, ami there wns no danger, therefore, of extinct volcanoes lying inland ever becoming active. The nest of volcanoes around Auckland was never likely to become a menace. The whole tendency of volcanic agency was toward coming to an end. Over certain areas.of (hp volcanic belt tho volcanoes had become extinct, owing to the cooling of the earth, and tho Greater distance from water, as the land had slowly risen. The thermal phenomena at Kotorua would slowly cease. It was not likely that there would ever, be another iarawera eruption.