New Process for Preserving Timber.

Manawatu Standard, Volume IX, Issue 129, 6 May 1885, Page 3

New Process for Preserving Timber.

About five years ugo the chemist of a corporation m the United States, ■winning to preserve shingles against decay, and also ruuder them inc<>m bustible, impregnated them with lime and salt by boiling them m a solution of IOHk of salt and 2011,s of lime with 250 gallons (200011*) water. Ten bundles of shingles were boiled until thoroughly .saturated, the pro cess costing 50c per 1000 shingle*. These prepared shingles have been used for roofing purposes, both with aud without the protec ion afforded by paint, and the result hap, says " Engineering " proved m every way satisfactory . Recently come prepared shingles were subjected to trials m competition with ordinary shingles. They were dipped into naptha and lighted, the ordinary shingle burning until consumed, while • the flame on the prepared shingle went out as soon as the naphtha was burned, without igniting* the shingle. A spark test made by a, burning' mixture of charcoal, sulphur, and saltpetre on the shingles burned the ordinary shingles, but only charred those which were prepared. Exposure to gas flames showed si mi lai resistance to combustion m the prepared shingles. The antiseptic properties of lime upon wood and iron are well Tcnown, the only element of uncertainty being the rate at which such lime aud salt deposits m the pores of the wood would be reiuoved by rain storms. The experience of five years shows thut this decrease is a slow one, and may be retained by paint. It is considered that such{preparalion.s 'nay be applied more thoroughly to green timber, where the sau sells are still Open and capable of absorbing moisture, than m seasoned stock, which cannot have so much permeability.