Preserving Timber.

Pelorus Guardian and Miners' Advocate., Volume 6, Issue 49, 21 June 1895, Page 3

Preserving Timber.

“ There is about to be introduced into England,” says Engineering , “a process of preserving timber which has been for some years in operation in the United States, the details of which have been worked out by Colonel Haskin. Ordinarily the treatment of timber to obviate decay consists in the application, after being dried, of some antiseptic —chloride of zinc, sulphate of copper, bichloride of mercury, and much more extensively, creosote. But Colonel Haskin believes that the timber in its green state has in itself the properties essential to preservation, and the process associated with his name is designed to utilise those properties. The wood in its green state is placed in a large airtight vessel, and is there subjected to an air pressure varying, according to the timber, from 1501 b to 2001 b to the square inch ; and this air is dried first and heated by passing through pipes over a stove, the ultimate temperature being from 200 deg to 450 deg Fahr., according to the nature of the wood. The effect is said to be a chemical change in those compounds albuminous, glutinous, resinous, or oleaginous—which constitnte the sap of the tree, so that the fluid matter becomes insoluble, and coagulates in the pores, preventing decomposition. This result is attained in about eight hours’ treatment for, say, a mahogany log 12 inches thick, the time varying with the thickness. The process has thus the merit at least of great rapidity, but time alone is the arbiter of its preserving qualities.”