105 
S AWIN G. SEASONING. 
SAWING. 
Where powerful sawing machinery is available it is better for all timbers and 
for neai ly all purposes than the comparatively primitive process of splitting and 
adzing. But an occasional hardwood log will not be welcome at a mill that is 
usually engaged in cutting up softwoods. The hardwood requires a different set 
of the saws and much greater care to prevent warping and cracking of the sawn 
product. The question is one of demand and adaptation. In Australia and 
Tasmania together there are hundreds of mills engaged almost exclusively in 
cutting up eucalypts into the various sizes and shapes required for building and 
the technical arts. Experience has developed the appliances and the skill 
necessary for overcoming the difficulties that these trees undoubtedly present 
when we put them under the saw. A full account of the methods employed would 
occupy too much space in this book; but one example may be given by way of 
illustration. If a sappy hardwood log is sawn down the middle, each half may 
spring into a curve. An expert at the bench will avoid this by first taking 
flitches off' his log and then dealing with the squared baulk. 
SEASONING. 
We shall the more intelligently handle our timber if we try to understand the 
life and structure of the trees from which it has been derived. A living and growing 
timber tree is an exceedingly complex organism continuously charged with water. 
The water, which holds nutrient salts in solution, is absorbed from the soil by the 
rootlets. Thence, by a force remotely like that which moves the blood in an 
animal, it passes up through the larger roots, through the stem, and through the 
branches to the leaves. The green leaves that we so much admire fulfil for the tree 
functions analogous to those of lungs and stomach in the animal. They exhale 
in invisible vapour the excess of their water; they inhale carbonic acid (carbon 
dioxide) ; they transmute selected elements into tissue food for feeding and 
building the tree. Hydrogen, oxygen, and nitrogen are supplied by the rising 
sap. Carbon in ample abundance is derived from the atmosphere. The prepared 
tissue food flows upward to the growing tips and downward under the bark to the 
smallest roots. It is the food of the cambium tissue, which annually forms new 
wood in addition to that of the previous year, new material for changing 
alburnum into duramen, and new bark to make good the expansion and waste at 
the surface of the tree. The countless cells and tubes and fibres of the wood are 
fashioned and built together with special adaptation to these two purposes: (a) 
The free passage of water from the rootlets to the leaves: (b) Resistance to the 
force of the wind. The bark provides a channel for conveying the prepared 
tissue food in the reverse direction, and further serves as a shield to protect the 
tender cambium. The medullary rays convey to the heart wood the materials 
necessary for completing its density. 
For the timber worker the truth of paramount importance here is that wood 
by its natural structure is freely pervious to water with the grain; but not so 
freely pervious across the grain. We have proof and illustration of this truth 
when we see a freshly felled sapling “bleeding” from the stump and perhaps from 
the severed part as well, or when we see a green log on a hot fire giving out its 
