152 
TIMBER AND TIMBER TREES. [chap. 
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 occa¬ 
sionally 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. 
