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, 



