CHAPTER IV. 
ON THE DEFECTS FOUND IN TREES. 
HAVING described the characteristic points of growing 
timber trees, it will perhaps be interesting if, before pro- 
ceeding to a detailed account of the various kinds, we 
were to give a description of some of the! defects to 
which trees are liable prior to their being felled and 
hewn, or otherwise prepared for the market. 
There is‘one defect so common to nearly all trees, that 
I will treat of it first. It is‘known to carpenters as the 
heart-shake.: It is met with to a greater or lesser extent 
in nearly every species of timber that we have to deal 
with, and as it has a very important bearing upon the 
value of the tree affected, we cannot afford to disregard 
it, inasmuch as the quantity of good and serviceable 
material obtainable from a log, depends almost entirely 
upon the distance we are constrained to go from the 
pith, or centre, in order to get clear of it. Experience 
has shown that among the woods least affected by the 
heart-shake are African Oak, or Teak, as it is sometimes 
called; Sabicu ; Cuba Mahogany ; and English Elm; 
while Indian Teak * and Australian Tewart have it in 
* In India, the forest officers have attributed the heart-shake in Teak 
to the ringing, or barking, the trees, to kill them before they are felled. 
It has, however, been proved that, where this has not been done, and the 
trees were felled green, heart-shake was found in them, 
