Page:A primer of forestry, with illustrations of the principal forest trees of Western Australia.djvu/26

20 First the axe, maul and wedge, then the pit-saw, then the waterwheel and vertical saw, then the steam engine vertical and circular saw, and finally the band-saw. Thus grew and developed the machinery used to fashion trees into timber. In Western Australia we have seen the evolution from pit-saw to band-saw, and the expansion of the timber milling business from the early part of the. 19th century until to-day. The total amount of timber exported to date amounts to 3,897,849 loads valued at £15,693,989. This timber exploitation in Western Australia consisted mainly of jarrah, until the opening of the Karridale mills near the Leeuwin in 1879, and of the Torbay and Denmark mills some years later. Those mills cut a great deal of karri. Again of late years there have been four mills cutting karri. It is unfortunate that there is no record of the quantities of karri cut from Karridale and Torbay and Denmark in the early days. From the time from which data are available, the volume of sawn karri turned out by these four mills has been over 1,000,000 cubic feet.

Minor Forest Produce.—The rapid development of the saw-milling business in this State has operated adversely in the matter of minor forest produce. Forestry has been sacrificed to the sawmiller and the demands of an export trade. In older lands, where the local demand for wood is so heavy that the utilisation of the whole tree is the practice, the tree is felled level with the ground and the bark, if it contains tannin, is removed and sold to the tanner. The small branches are converted into faggots for household kindling, the larger branches are split into fuel, and the big limbs into sleepers. Waste from the mill is converted by destructive distillation into charcoal, acetic acid, wood alcohol, tars and other valuable distillates. Some woods, whose structure particularly fits them for the purpose, are used for the manufacture of paper pulp, artificial silk, etc. In tan barks Western Australia possesses the valuable mallet, which contains no less than 45 per cent, of tannin, and of which since 1903 we have exported an amount valued at £929,808. It has been a case of "killing the goose that laid the golden egg," and to-day we have very little mallet left. Then there are gums and resins. The forests of the old world and the new yield us turpentine and varnish gums, such as kauri from New Zealand, copal from West Africa, and gum arabic. Then there are the oils, eucalyptus oil being one of those produced in largest quantity; the drugs, e.g., quinine from South America, camphor from Formosa, kola from West Africa; and foods, such as cocoa and the many nuts and fruits.

Indirect Value of the Forests.—Forests, as well as having a direct value, have an indirect value. In the first place, they have an influence on the climate of the district or province in which they grow. Research work covering a long period in France has shown that in the first place the temperature of the air is lower in a forest than in the surrounding country. The mean annual forest temperature is lower and also the mean monthly forest temperatures are lower. The mean winter forest temperatures do not show, however, such a difference as do the average summer temperatures. Taking the daily mean temperatures, we find on the hottest day in the year a much lower. mean temperature in the forest than outside, and a lower maximum. This equalising of the temperature is a very valuable function of the forest. Unfortunately no work has yet been done in Australia to find the exact effect of forests on the temperature of the air. There is no reason to suppose that the forests of eucalypts should differ fundamentally in their action in this regard from the forests of the Old World. It is right, however, to point out that there is a difference between the actions of different species. The action is more marked, for instance, under broad-leafed deciduous (i.e., shedding their leaves annually) trees than under pines, spruces and firs. Forests in the growing season exert more influence than during the dead season, whether they are evergreen or not. Until a thorough investigation into forest meteorology has been carried out in Western Australia, we cannot say how great is the influence of our forests on