Fourth Meeting. July 17, 1870.
Hon. Mr. Mantell, F.G.S., President, in the chair.
Dr. Hector read a paper for Mr. Duigan, which went to show that the earth of New Zealand is as good a conductor of electricity as that of any other country. The paper elicited some comment, some thinking the weather, and the nature of the soil in particular localities, influence electrical power in a great degree.
Mr. Potts read a paper “On the Great Auk, or Northern Penguin,” (see Transactions,) and exhibited a drawing of an egg of that variety, which he possesses. Although the bird at one time abounded at the Orkneys, Auckland, and Farroe Islands, it is very rare now, if, indeed, it is not entirely extinct, a view which is shared by Professor Owen and other eminent naturalists. They base their belief chiefly on the fact, that notwithstanding the many expeditions that have been sent out during late years, no mention has been made of the Great Auk in any of their records. There are those, however, who still believe that the bird is not yet extinct, and think that it may have retired to the lonely and surflashed Skerries in the Northern Sea. So high a value is set upon these eggs, owing to their exceeding rarity, that one virtuoso gave £30 for a
single specimen; and a lucrative trade was driven in manufactured specimens for a short time in France, until the swindle was discovered.
Mr. Crawford read a paper throwing out suggestions as to the advisability of using india-rubber tires on wooden tramways. The idea suggested itself to him by reading in the news by last mail, that one of the road traction engines at home had run over carrots and turnips without crushing them. As the use of india-rubber tires is general in road steamers, he thought the subject worthy of consideration. If we could, by means of elastic tires, effect economy, and retain a fair rate of speed, we might be enabled to dispense with iron rails.
Mr. George thought that from the market value of india-rubber, the suggestion, although worthy of consideration, would be expensive if acted on.
Mr. R. Pharazyn said it had been found in practice that the indiarubber wore too quickly, that the tires became soon abraded, and had led to the practice lately of covering the tires with small bars of steel.
Mr. Gillies said his experience had led him to a quite contrary view. So far from the india-rubber wearing away rapidly, it had been found to last in a remarkable manner. He had caused enquiries to be made before importing one of these engines for the Province of Auckland, and heard that one had been in constant use for six months on a granite metalled road, and after that wear and tear there was still observable on the tire the name of a workman, which had apparantly been cut with a knife or something of that sort.
Several speakers were of opinion that india-rubber tires did not wear out at all rapidly, and had been originally introduced to prevent vibration, which was found to have a destructive effect on the engines; while another thought india-rubber was used not so much to prevent vibration in the vehicle, as it was to preserve the road, as traction engines had been found so destructive to macadamized roads, as to lead almost to their prohibition. A third was of opinion that india-rubber tires had become unpopular at home because they were positively dangerous, the engines passing along almost noiselessly, are often on top of a heedless traveller before he is aware of it. But all were of opinion that indiarubber would be found a most expensive addition to rolling stock.
Some interesting information relative to the Southland (Invercargill and Oreti) railway was given by Mr. Hamilton. The rails on that line were originally of timber, being planks eight inches square and twelve feet long. They were well supported by sleepers. But it was found that the wood warped so much through the effects of sun and weather,
that the ends of the rails were continually springing up with the weight of the engine going across. The ends were then fastened down with metal plates; but they then split and got soft. In a couple of years they became so crushed as to be useless, and he did not believe there was the slightest vestige of them now remaining.
In answer to a question from the Chair, respecting the eruption of Tongariro, Mr. Cox said although he had just come down the coast, he had not been within sixty miles of Tongariro. At that distance, however, he had heard the rumbling of its artillery, and had seen the reflection in the sky to the north of the Mohaka river.
Dr. Hector said if all be true that is said about the eruption, it is the first instance, within the recollection of the Maoris, of an eruption of lava, though eruptions of steam and clouds of ashes had been common enough.
Several specimens of the Elephant Fish (Callorhynchus) were exhibited by Dr. Hector,—one of which showing the young fish enclosed in the egg had been recently picked up on the coast.
The discussion on flax was resumed, Dr. Hector reporting the progress made by the Commission during the week, the full particulars of which will shortly be published. To make the tests more satisfactory, the commissioners had made an improvement in the arrangement for testing the strength of samples, that was more satisfactory than the mode adopted at first; and as a comparative test of the relative strength of fibres, nothing could have been fairer. As before, the Maori dressed flax retained its superiority in point of strength. Acting on a suggestion of Mr. Davis (an assistant), Dr. Hector said he was experimenting to ascertain if atmospheric pressure was not sufficient to compel the lateral adhesion of the flax fibre after the gum had been released. Some doubts were entertained at last meeting that the gum could be released without detriment to the fibre, as the ultimate threads of the leaf are ascertained, by microscopical examination, not to be more than two inches long. So far the experiment promised successfully.
A sample of flax prepared by a new process of Mr. Plimmer's was also exhibited. The object of the improvement is to prepare flax for a subsequent retting process by dividing the fibre without crushing it. This is sought to be done by putting the leaves through rollers laterally, the usual plan being endwise. In going through, the leaf is considerably widened by the fibres being divided. The samples exhibited were on a small scale; and some doubt was expressed whether the result would be equally satisfactory when tried on a large scale with whole leaves.