Page:Transactions NZ Institute Volume 9 Supplement.djvu/21

Rh Mr. McLean suggested the willow of Australia as suitable for a fence.

The President did not think the Osage orange would do. On the West Coast, flax plants were used to protect the railway lines from blown sand.

Mr. J. Young stated that the Acacia, mentioned by Mr. Graham, did not last long and took fire quickly.

2. "On Charring Timber as a Protection from Teredo," by J. Buchanan, F.L.S. (Transactions, p. 183.)

Mr. W. R. E. Brown would like to know whether charring prevented the timber from decaying in the ground, or only from the Teredo under water.

Mr. O'Neill thought that charring would protect timber from decay. He had noticed that at Auckland the totara piles did not seem affected by the Teredo, while the jarrah piles were completely honeycombed. He was inclined to think that manuka withstood the attack of Teredo.

Mr. J. Young said that charring was very successful in Tasmania and Australia in fencing. The part remaining in the ground, when charred, was found to be quite fresh, but there was not sufficient attention paid to the time for splitting the woods.

Dr. Newman thought that the subject had become rather mixed up. The attack by the Teredo was quite a different thing from the attack by the insect in the ground.

Mr. J. T. Thomson did not think much of charring except in certain cases. Would charring protect soft wood? He thought that the timber under discussion was protected because it was hard. The Teredo seemed worst where fresh and salt water met. He considered that manuka would resist the Teredo without charring. Except for soft woods he did not think charring of much use; he would like to see greater proofs before he believed in this process for the protection of wood.

Mr. Campbell considered it proved, from specimens on the table, that charring did protect wood from the attack of the Teredo. Charring acted on hard timber as creosote did on soft woods.

Mr. Kirk thought that Mr. Buchanan had quite proved the beneficial effects of charring, so that it was not necessary for him to say much. He had seen manuka, when not protected by the mud, completely eaten through by the Teredo. He did not consider that we had any timber which could resist the Teredo, unless artificial means for its protection were employed.

Dr. Hector was of opinion that the manuka piles at Port Chalmers, referred to by Mr. Thomson, were protected from the Teredo by the coating of tunicate molluscs (Boltenia) that adhered to them. He also thought the Teredo in pure salt water was far more destructive than in rivers.

Mr. Marten, from his experience in the south, did not think that charring was of much service for fencing-posts.

Mr. Graham thought it would be interesting to examine the specimens on the table microscopically, to ascertain whether they had both been of equal quality before being experimented on.

Mr. Buchanan, in reply, stated he did not think charring would protect soft inferior timber, but there was a large amount of medium class timber in New Zealand that would resist the Teredo if charred. He considered that charring fencing-posts was necessary on land to protect the timber from the boring beetle, which might be called the land Teredo.