xxvi.] JARRAH. 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., XCVL, 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 Ibs. weight only, or about 171-5 Ibs. 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. 



