OTAGO INSTITUTE.

Evening Star, Volume VIII, Issue 2247, 20 July 1870, Page 2

OTAGO INSTITUTE.

A meeting of the Otago Institute was held last evening iu the Provincial Council Hall ; Mr Webb in the chair. There was a more than usually large attendance of members and visitors ; the body of the Hall being well filled.

After the usual preliminary business had been disposed of, Mr James M'Kerrow read a paper on the physical geography of the Lake district of Otago. He dwelt upon the evidence which exists that these lakes lie in basins which had been excavated by glacier action. H i s remarks were illustrated by a longitudinal section of Lake Wakatip, constructed according to the data afforded by recent systematic soundings. Referring to the theory of unequal subsidence of the country, which has found favor with Dr Hector and which is used by him to account for these rock-bound lake basins, he expressed his conviction that no such explanation was demanded by the phenomena. He referred te the valuable effects of the lakes in regulating to a great extent the flow of water in the rivers, of whose systems they form part, thus mitigating the effects of the rapid melting of snow which occurs when the warm north-west winds prevail, storing the surplus to provide a steady flow during that portion of the year when the rivers would otherwise be very much lower than they are. In conclusion, ho spoke of the Lake districts as containing within themselves all the elements of support fer a largo community—a delightful climate, good agricultral and pastoral lands, valuable mineral resources, and a complete system «f internal water communication. Mr R. Gillirs said that ho had been asked by Mr iM'Korrow before the meeting to compare what he had said with Dr Hector’s remarks on the same subject. He had done so, and though nob pretending to geological knowledge, he must confess that he saw some difficulties in the way of accounting for all the phenomena of the the Lake district, if the theory of unequal subsidence was to be rejected. Dr Hector’s idea was that the axis of the glaciated country and the western part of the region had subsided more rapidly and to a much greater extent than the eastern portion had. He recommended all members to peruse Dr Hector’s lecture in the volume of Transactions just distributed, when they would find this and other points of extreme interest discussed.

M r J, T. Thomson expressed bis concurrence in Mr M'Kerrow’s views as to the sufficiency of glaciers—such as we must suppose existed during what is termed the glacial period of the recent epoch—to scoop out such valleys as that now occupied by Lake Wakatipu. He exhibited a diagram showing where the points of greatest pressure would be in the case of a glacier of some 3000 feet in thickness occupying what is now the position of that Lake, and showed that it is by no means necessary to suppose that the excavation which would result should pass clean through to the sea; if wo admit that the Kingston end of the Lake was at the time on or about the sea level.

Mr A. H. Ross called attention to Dr Hector's account of Milford and other Sounds, given in a report of the expedition to the West Coast, and expressed his opinion that the meaning of the passage in Dr Hector’s lecture before the New Zealand Institute —(Transactions, vol. ii., pp. 370-374) —had been misconceived by Mr M'Kerrow. After some explanations by Mr M'Kerbow, Mr Gillies, the Chairman, and Mr Thomson, Mr Jbfcoat expressed his admiration of Mr M'Kerrow’s paper, and his coincidence with him upon the points under discussion. Mr G. M. Barr, without expressing an opinion on the point of difference between previous speakers and the theory laid down by Dr Hector, said he had carefully read the lecture which had been referred to, and his impression was that it was somewhat want : ing in clearness. He did not feel sure that there was any substantial difference between Dr Hector and the local observers. He called attention to the very interesting subject of the circulation of the water of the Lake, as to which a course of thcrmometrlcal soundings was necessary to yield the requisite data. He suggested that it was contrary to the ordinary course of nature for the lower strata of the water to lie stagnant, and that either springs at the bottpm of the Lake, or the difference of tompprature between its waters and those of the streams flowing into it from the snow-covered mountains, might serve to keep up a circulation. Mr M'Kerrow said no observations of temperature had been made for depths of over 20 feet, but these had led to the conclusion that a permanent temperature of 52 ° reigns at a moderate depth. The temperature of the Lake of Geneva at about 150 feet was constant at 41 0 . Mr Beal explained how glaciers of the mass spoken of by Mr Thomson might have existed in New Zealand during the glacial epoch. After a few words from Mr M'Kerrow in reply to various speakers, the meeting adjourned till Tuesday, 9th August, when Mr Skey’s and Mr Purdie’s papers will be read. There was a discussion as to the suitable hour of meeting, when it was resolved that the next meeting should be held at seven o’clock instead of eight. Nine new members were elected. The Chairman announced that the honorary treasurer would be happy to receive the subscriptions of members for the current year, which are now due.