199 



Speaking more particularly of Gum trees, Sir William Macarthur wrote in 1854, 

 with knowledge chiefly obtained from the counties of Cumberland and Camden, New 

 South Wales — 



When at full maturity they are rarely sound at heart., and even vrhen they are so, the immediate 

 heartwood is of no value on account of its extreme brittleness. In sawing up log into scantlings or boards> 

 the heart is always rejected. The direction in which the larger species split most freely is never from the 

 bark to the heart (technically speaking, the " bursting " way), but in concentric circles round the latter. 



G. A. Julius remarks that — 



" Contrary to general practice in the case of other chief timbers of the world, the heartwood core of 

 the Eucalypts is to be avoided. In Western Australian woods this applies specially to Jarrah, Karri, 

 Blackbutt, and Wandoo, and generally to others. Specifications for cut timbers should therefore require 

 freedom from heartwood, except in the case of piles, which are better round than squared. Sapwood, on 

 the other hand, rarely measures above an inch in thickness, and being often almost as hard as the inner 

 wood, hardly needs to be particularly excluded, except in cases of special importance." (" W.A. Timber 

 Tests," 1908 Edition (c). p. 11.) 



Speaking generally, trees with thin sap woods are found in regions of low rainfall, 

 or in well-drained situations. For example, E. rostrata, which grows on the banks of 

 streams (or depressions which become streams when the rain comes), has a comparatively 

 thick sapwood, while E. tricolor, E. intertexta, E. salmonopliloia, which may be found 

 in the same district, but which frequent drier situations, have a thinner sapwood. 



Making allowance for the small diameters of the trunks, the sapwoods of Mallees 

 are very thin. 



Trees with thick sapwood (which, by the way, is readily attacked by insects) 

 include E. maculata and the Corymbosae generally, E. papuana (and some other Ango- 

 phoroidea?). E. obliqua, a Stringybark of Tasmania and Victoria, and a Messmate in 

 New South Wales, is another. 



Prehaps the list of pests which attack the Eucalyptus timbers, and which are 

 enumerated in Part LXX of my " Forest Flora of New South Wales," may be referred 

 to in this connection. 



Seasoning. 



Under this heading Schlich (Fisher), iv, 53, has some notes as follows : — 



(a) Shrinkage of dried wood. 



(b) Cracks in dried wood. 



(c) The swelling of dried wood exposed to moisture. 



(d) Warping of timber. 



The timbers selected for illustrative purposes are those commonly in evidence 

 in European forestry, and therefore do not include Eucalypts, but the notes are well 

 worthy of reference in connection with a subject which has received but little scientific 

 attention in regard to this genus. 



