Go to National Library of New Zealand Te Puna Mātauranga o Aotearoa
Volume 7, 1874
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Charles Knight, F.R.C.S., President, in the chair.

New members.—Frederick Bull, E. H. Bold, C.E.

1.

“Notes on Dr. Haast's supposed Pleistocene Glaciation of New Zealand,” by W. T. L. Travers, F.L.S. (Transactions, p. 409.)

Mr. Crawford said that, without entering on the subject of glaciation, he must certainly disagree with the author in his view that the S.E. trades prevailed over Australia, and thought that, by his diagram, he had stabbed his own argument with a stiletto of chalk. No doubt it was right and proper that the S.E. trades should blow over Australia, but unfortunately, as a matter of fact, they did not. They only passed over the N.E. corner, and it was well known that hot, dry winds from the N.W. were prevalent along the eastern portions of Australia, at least south of Brisbane.

Mr. J. A. Wilson thought the extent of surface in Australia traversed by the S.E. trades was greater than stated by Mr. Crawford. He agreed with the author that the S.E. trades did blow on the coast of Australia, and thought N.W. monsoons were due to the heated interior of the continent, a view which had escaped the notice of the author of the paper. He did not believe the N.W. winds of Australia reached New Zealand, and they were certainly never encountered on the ocean surface that intervenes; whether or not they were in the higher regions of the atmosphere could only be determined by a balloon. The hot winds of Canterbury, he thought, had nothing to

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do with the Australian hot winds, but were due to the evolution of moisture from winds passing over the Southern Alps.

Dr. Hector said the paper just read touched on nearly every branch of the physical geography of New Zealand, and opened a great variety of debatable questions. Mr. Travers considered that Dr. Haast was wrong in the period to which he attributed the glacial conditions, and also in the cause he suggested for them. Agreeing with the author that vague assumptions were unscientific, he had anxiously expected some definition of the meaning that he attached to the terms pleistocene and pliocene, as in that lay the first ground of difference with Dr. Haast. The former word was used by Sir Charles Lyell for certain terrestrial or drift beds that are contemporaneous with newer pliocene; in fact, an extension back in time, in some localities, of post-tertiary conditions. Owing to its frequent mis-application to merely post-pliocene strata, Sir Charles recommended that the term should be dropped, but, if used in its original and extended sense, he (Dr. Hector) thought it would be useful to retain it, and it seemed to him that it would suit Mr. Travers' view, as he understood him to hold that no great change in the fauna and flora of the islands had taken place since the great glacier period. Apart from this verbal consideration, he thought the evidence for classifying even our marine tertiary strata did not, except as a matter of convenience, warrant our applying to them terms that have definite meanings in the other hemisphere, where the geology has been more fully worked out. With reference to Dr. Haast's opinions, the report quoted from so largely was neither his first nor his last, and among them were many views in variance with each other. He did not attach much importance to this so long as the facts recorded were right, as speculations on this and kindred subjects were only muffled echoes of discussion in the old country, where opinions change like the fashions. The extensive citations just made from Geikie's work on the “Great Ice Age” were a case in point. It being a new work, was treated as final authority, but he thought that, even in passages read, there were views that had already been disputed and modified. Leaving the question of whether the glaciers were largest during an extended pleistocene period, or were contemporaneous with pliocene marine deposits elsewhere, which is Mr. Travers' view, as still open, he agreed with the author's idea of the cause of the former great size of the glaciers, though not requiring for his theory such an extreme degree of elevation of the land. He had previously expressed his opinion that there must have been a greater extent of land above the snow line, partly due to increased height, but also due to the more massive form of the mountains before they had been cut up into valleys, ridges, and peaks, but that a third cause may be found in changes in the physical geography of the surrounding region. The winds had been described as blowing steadily from certain quarters which did not bring them

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over the Australian continent, but the regular gyration of the winds through successive quarters had been quite overlooked. This rotation is performed in from five to seven days, and through its influence large columns of the atmosphere are transferred from one area to another. Prevalent wind in New Zealand only means that there is a preponderance of wind from a certain quarter, and not a steady wind like the trades. The fact is undoubted that warm winds from the N.W. do impinge on New Zealand, but the only fair way to discuss this subject is by making use of the abundant meteorological data which have been accumulated.