XXVI. ] JARRALH. 191 
growth, and hence the conversion of the faulty trees is 
necessarily restricted to the dimensions of flitches cut 
clear of the centre. 
One peculiarity was noticed in the sample referred to, 
some of the logs had cavities or blisters, varying from 
one to several inches in length in the longitudinal 
direction of the woody layers, and spreading from I to 3 
inches concentrically, which occurred, like the cup-shake, 
at various distances from the pith, and at intervals of a 
few feet along the line of the trunk of the tree. These 
cavities were partially filled with a hard secretion of resin 
or gum, which made up in some measure for the solidity, 
although it did not impart the strength which would 
compensate for the deficiency of the cohesive properties 
common to the annual layers.* 
From what has been stated respecting the Jarrah 
timber received at Woolwich, it will be readily supposed 
that the authorities there did not look upon it with 
favour, or any desire to employ it for ship-building 
purposes. It therefore passed to some of the minor 
services of the yard, and it was while under conversion 
for these ordinary and inferior works that I took the 
opportunity of making the experiments which are given 
in detail in Tables XCV., XCVLI, and XCVII. 
It is a noticeable fact in connection with the experi- 
ments, that all the specimens tried proved deficient in 
strength and tenacity, by breaking off suddenly with a 
short fracture, under an average transverse strain of 
about 686 lbs. weight only, or about 171°5 lbs. to the 
square inch of sectional area. 
Since the foregoing was prepared I have seen some 
correspondence between the Home and Colonial Govern- 
* This peculiar defect is met with in several of the Eucalyptus species, 
and may occasionally be seen in the Firs and Pines, 
