Page:Timber and Timber Trees, Native and Foreign.djvu/335

CHAP. XXXIX.] The winter-felled logs were sounder, less rent byshakes, and the centres or early growth generally showed less of incipient decay than the spring-felled. The centres in both, however, unless they are carefully pro¬ tected from the weather, are liable to be deteriorated at the ends after being about three years in store, and if exposed for a longer period, the deterioration will be more serious, inasmuch as the shakes will be deeper and more open, and instead of the early stage of decomposition at the ends, there may be decided rot supervening, and involving great waste whenever it is required to be brought into use. The Tewart of Australia and the Greenheart of Demerara are, however, notable exceptions to this, for on these two woods time and weather have little effect; they seem to be almost imperishable. Ten to twelve years seems but a short time compared with the usual and common duration of timber, and when we hear of the timber framework and fitments of old buildings being found in a sound state after having stood the test of ages, I think it should be understood that it could only have been under certain very favourable conditions.

First. That the timber was of good quality when selected for employment.

Secondly. That it was at least moderately seasoned when brought into use.

Thirdly. That it was placed in a favourable position in the building for lasting, and where it had a free circulation of air about it, without being in a draught.

Fourthly. That the temperature was moderate and regular, and not subject to sudden calorific changes, or even to too strong a light.

The most effectual way to preserve good timber is to partially season it in as natural a way as possible before