388 
A few years are always added on to this result to allow of a teak 
seedling to have established itself. 
In the same forest as above 24 stumps and logs were measured 
and the rings counted. The result "worked out to 149 years to attain 
a girth of 7', and for the purposes of the working plan 150 years "was 
decided upon as the age. 
The above illustrates with what accuracy this little instrument 
will gauge the rate of growth of trees. Of course in using this instru- 
ment iron woods must be avoided, or it will snap off. 
It will be successful in woods considerably harder than teak, but 
would I fancy be useless in trees such as ChengaJ, Merbau, Penaga. 
Belian, etc. However as these trees do not appear to have definite 
and well marked annual rings we are thrown back here upon a very 
slow 7 and tedious method, but one which is of course absolutely ac- 
curate, i.e., to measure annually as many trees as possible, and to take 
trees of all sizes. At first sight it would seem that this w T ould mean 
waiting 100 years or more for results, but this is not the case. Thus 
taking the divisions into classes as in India above shewn, we will 
suppose that of the 407 trees I have had measured in the F. M. S* 
forests. 
100 are in class 10 to 7 girth 
100 ,, „ II 4V 
100 ., „ .. HI 3' 
107 „ „ „ IV under 
6 ' 
41 
3’ 
at the time of first measurement. Then it is obviously not necessary 
to continue measuring a tree in class IV right through all the classes 
but only until it has reached class III, i.e., suppose that we find that 
it takes' 40 years for a tree to reach 3' in girth, 25 years to pass through 
clogs III, 30 years to pass throuh class II and 35 years to pass from 
6' to 7', then we will in 40 years knowhow 7 long it takes the average 
tree to reach a girth of 7 feet i.e., 130 years. As regards the actual 
results so far as we have gone. I have before me 3 years of measure- 
ments of Chengal ( Balanocarpus ) and Merbau (Afzelia) taken in Bilut 
Reserve near Raub. 
These big forest trees are measured at 20 from the ground to 
avoid buttresses. 
The forty Chengal trees shew these results : — 
Class I 
{ 
{• 
.28" 
Class II 
.58" 
.29" 
Class III 
1.25" 
.62" 
Class IV 
.75" 
.37” 
Average increase in 
girth in two years. 
Average increase in 
girth in one year. 
Theses results if they could be relied upon would be of course dis- 
couraging as it w T ould take a tree at this rate 97 years to attain a girth 
of 3 feet, 29 years to pass from 3' to 44', 62 years to pass from 4? to 6 
and 42 years from 6' to 7', a total of 230 years. 
As a matter of fact measurements cannot be relied upon until 
after about 10 or 12 years because in dealing with these large timber 
trees the bark is constantly breaking away owing to expansion by 
