Title: Canadian forest industries 1916
Identifier: canadianforest1916donm (find matches)
Year: 1916 (1910s)
Authors:
Subjects: Lumbering; Forests and forestry; Forest products; Wood-pulp industry; Wood-using industries
Publisher: Don Mills, Ont. : Southam Business Publications
Contributing Library: Fisher - University of Toronto
Digitizing Sponsor: University of Toronto

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Mine timber in early stage of decay. Decayed Spruce tie (untreated) removed Microphotograph of transverse section Microphograph of transverse section showing growth of fungus. during fifth year of service. of White Pine. Note numerous of White Birch, a diffuse porous large resin canals. wood, i.e., pores uniform in spring and summer wood. The Preservative Treatment of Timber By W. G. Mitchell* Alarge proportion of timber used for industrial purposes is required for service under conditions which are favorable for deterioration from decay and insect attack. These con- ditions vary widely, and similarly, the means which may be adopted for the reduction of losses from such causes are determined largely by the nature of the service for which timber is used. The artificial preservation of timber is not a new practice, but recent years have developed many improvements in methods and accumulated a varied and extensive experience which has yielded much definite knowledge regarding its possibilities. It is impossible to estimate even approximately the actual value of timber annually destroyed in Canada by the agencies above noted, but the situation is certainly serious enough to warrant very careful consideration of any means for preventing or reducing such losses. The Natural Durability of Wood Woods of various species differ greatly in their natural resistance to decay. The cedars, oaks and Douglas fir are among the most dur- able of Canadian commercial woods, while ranging below these in an estimated classification on a basis of natural durability are the tam- aracks, the hemlocks, the pines, the spruces and such hardwoods as beech, birch and maple. Variations in this respect apply to the sep- arate species of above woods. Thus, white oak is by far the most durable of all the oaks, and black spruce is regarded as more durable than the other Eastern spruces,—red and white. The striking dififer- * Chief of Division of Wood Preservation, Forest Products Laboratories of Carrda.

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