Page:Timber and Timber Trees, Native and Foreign.djvu/172

152 Of the durability of the Greenheart timber, we have had sufficient evidence in the large stock of this wood kept in the royal dockyards, where it stood the test of many years' exposure to the weather, without being in any but the least degree affected by it. At Woolwich, the only place, I believe, where any attempt was made to protect it for preservation, the experiment to some extent failed, the ends of the logs splitting open rather more in the covered stacks than in those which were left exposed, while, in other respects, there was absolutely no difference observable between the two parcels.

It is characteristic, however, of the Greenheart timber to split in this way, and to open clean across the pith in seasoning, there being frequently two such splits crossing each other at nearly right angles, and cleaving the log, at the end, into four segments; but these do not, usually, extend more than two or three feet up from the end.

This serious defect is, to some extent, compensated for by the fact that the logs do not split and form deep shakes along the sides in the seasoning, as do most other woods; so that there is not, after all, more than the ordinary amount of waste in the conversion of this kind of timber. Further, it is remarkable for its freedom from knots, and also for its general soundness, the only defect, beyond the splitting of the ends before mentioned, being a cross fracture of the longitudinal fibres, which is occasionally seen, but can seldom be detected before the log is under conversion.

The alburnum, or sap of this wood, is of a dark greenish colour, and differs so little in appearance from the heartwood, that it is often difficult.to distinguish the one from the other. In quantity it is usually excessive frequently amounting to a fifth, and sometimes even to a third, of the diameter of the tree. Few people, however