121 
XIT. On the Strength, Durability, and Value of the 
Timber of the Blue Gum of Tasmania, and of some 
other Eucalypti. for Ship-building, dc. By JAMES 
MircuHe.., Hsq., D.A.C.G. [Read 12th November, 
1851.] 
THE experiments detailed in this paper were undertaken 
with the view of ascertaining the strength of the Blue Gum, 
known as the Ship-building Timber of this Colony, as com- 
pared with the results of similar experiments made upon the 
woods used for like purposes in England and India. 
The details of the experiments upon the English and 
Indian woods will be found in Professor Barlow’s “ Essay 
on the Strength and Stress of Timber ;” but at greater length 
on the latter in the condensed table of Capt. H. C. Baker's 
experiments under the article ‘‘ Timber,” in the last edition 
of the British Encyclopedia. Extracts have been taken 
from both these works for comparison. 
The results are also given of a series of experiments on the 
Stringy-bark, a Gum wood extensively used in this and the 
neighbouring Colonies for house-building and general pur- 
poses. The specimens experimented upon were chosen be- 
cause their ages were vouched by the gentlemen who supplied 
them, and not on account of their being specially calculated to 
sustain great weights. Pieces could, I have no doubt, be 
found capable of bearing greater weights than any I have 
recorded. 
The apparatus used for testing the transverse strength 
consisted of two strong pieces of frame-work, 7 feet asunder, 
attached to the sides of asmall buildmg. The deflection was 
