On Artificial Stone.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 2, 1869, Page 411

By A. G. Purchas, M. D. (4.) “On Artificial Stone,” by Dr. Purchas. The author observed, that some time ago he had written to the Company which had been started in England for the preparation of artificial stone, making some inquiries regarding the solution required for the hardening of the material. The stone was coming into great use, and had been found much more durable and waterproof than brick. In reply he had received full information regarding the process, and would like a sub-committee appointed to investigate the matter, in conjunction with himself, with a view to bringing it under the notice of the Society. He sand at first written inquiring into the system for the purpose of adapting it to the iron sand; but as the question of working the sand had been practically settled, it was not of much value for that purpose then. It might, however, be applied for the preservation of some public buildings, such as the Supreme Court, where he understood the Bath stone was crumbling away. The damp brick houses might also be improved by a coating of the solution. He had applied some of the solution to a small quantity of iron sand, a specimen of which he had brought for the inspection of the members, and from which it would be seen that the sand could be hardened. The President thought the matter was more one for the consideration of the council of the Society than for a general meeting. Third Meeting. July 5, 1869. T. B. Gillies, President, in the chair. The names of the following new members were announced:—Messrs. J. Roberton, J. S. Macfarlane, E. Wayte, F. E. Manning, D. O'Keefe, A. Lascelles, T. Morrin, G. M. Mitford, J. A. Wilson, J. M ‘Effer Shera, Major Mair. A list of donations to the Museum was read by the Secretary. Memoranda respecting the Tidal Phenomena observed in New Zealand in August last, compiled by Mr. J. M. Wayland, were read by the Secretary. (See Vol. i. p. 101.) Dr. Purchas remarked that shortly after the time it occurred some very interesting accounts of the tidal wave appeared in the newspapers, and it would it be well if the Secretary could obtain these also, and preserve them along with Mr. Wayland's memoranda.

Mr. J. A. Wilson said he had made many inquiries amongst the old inhabitants about a wave that reached the Bay of Islands shortly after the great earthquake at Concepcion, but he had not been able to glean many particulars. The Chairman said they could easily ascertain the telegraphic times of the late tidal wave's impinging on New Zealand, as these were recorded at the time, and transmitted to the General Government. Papers read:— (1.) “On the Surface-fall of Water, as a guide for Under Drainage,” by J. Baber, C. E. (See ante, p. 213.) Mr. Stewart, C. E., said Mr. Baber's plan was very good so long as the ground was pretty regular, but it would not do for a rolling field where the drains could not be put in. In all cases he was of opinion the chains should be placed as nearly parallel as possible, whether they were 3, 6, 9, 12, 15, 18, or 22 feet apart, and so on, but not at right angles to the contour. The smaller drains might be of one and a-half inch tiles, and the larger of three inches, with a main drain also at right angles. The object of a drain was not only to take water off the surface, but also to let water and air into it. Captain Hutton was disposed to agree with Mr. Baber, for if the ground was steep and the line of swiftest descent chosen, the drains would speedily choke. Mr. Buckland said they might place their drains as they pleased, but water would go downhill, and the steeper the quicker. Mr. Baber: But suppose you have a hill? Mr. Buckland: We take them ound a hill, and then we must take off the water slowly. One of the greatest difficulties was when they came to a land spring; they must tap that. Mr. David Hay said they would find a good guide to draining in the vegetation that grew on the top of it. No general rule could be laid down, however, except for clay soils, and for these only if of an equal medium. Sometimes they were placed 15 or 20 feet apart, according to the quality of the soil. All drains should be angled where the ground was steep, but those drains that were semi-circular had been found to draw better. The ditches should also be well scoured out, and wells sunk at the mouth of each drain. It was well known that drained ground was several degrees warmer than the undrained, and where air and moisture got to the roots of plants vegetation proceeded better. Mr. Buckland said he believed that deep drains, or any kind of drains, were of little value unless they also subsoiled the ground. In the neighbourhood of Mangere it had been observed that the drains did not carry off the water as before, and the cause, he thought, was that the land had been “puddled” by the cattle. The effect of draining on the potato crop was in some cases very remarkable. Immediately over the drain the potatoes were saved, while all around they were lost with rot for want of proper drainage. He doubted if Mr. Baber's theory could be reduced to practice, for nothing, in his opinion, could regulate drainage but the gravitation of the water. Mr. Boardman said they had just heard two statements that he could not reconcile. Mr. Buckland said the potatoes were saved by being over the drain, and yet Mr. Stewart said they were required to put water into the ground. Now, there was no logical sequence in the two statements, for on Mr. Buckland's theory the potatoes supplied with the additional water would rot. Mr. Stewart: But when sub-soiling and deep-drainage are carried out, the sub-soil becomes the right soil, and the surplus water is taken off by deep drains. Captain Hutton said, with reference to the remark of Mr. Buckland that deep drains did not carry off water now so quickly as formerly, he might observe that the surface of the volcanic soil of New Zealand was not soil, but soil in the process of formation. Volcanic soils do not decompose very rapidly, as we see at the Shortland diggings, where the soil is a tenacious mud. Where the soil is light and porous, drainage is easy, but light volcanic soils will get heavier; and he thought, if the drains alluded to by Mr. Buckland were too far apart, that would account for the difference. Mr. Baber said that drains should always be at right angles to the contour of the land. The Chairman said that no rule was applicable, but there were a few general rules that might serve as a guide. Mr. Baber's plan not to run the drain straight across had not been well understood, but these drains would then lie in the line of steepest descent, while, by placing them at right angles to the contour, Mr. Baber only stated what was in harmony with a general law. (2.) A communication from Mr. Hawkins, North Shore, relative to the decrease in the quantity of honey found in beehives was read by the Secretary, in which the author gave, as his opinion, that the reason was owing to the honey-producing shrubs being destroyed by browsing, and that the honey-yielding districts had become overstocked with bees. Mr. Buckland said his son was a bee-man, and his experience corroborated the observations that had been made this night, and at previous meetings. He had found

that the bees only produced as much honey as would keep the young bees alive, and therefore when he found the bees were not making honey he removed it. Dr. Horne said he did not think it was so much owing to the browsing of the cattle as to certainty of food at all seasons. The very same thing had been observed in New Plymouth, when he first settled there. The bees had plenty of clover, and when they found that they could get honey in the winter as well as in the summer they did not lay up any.