756 
PROCEEDINGS OF SECTION H. 
two piles driven of this timber, the bark being left on, but no sheath- 
ing applied, and have recently examined them ; and the results are as 
follow, viz. : — 
One pile driven four years ago — not attacked yet. One pile driven 
two and a-half years ago — already partly eaten by the Teredo. I think this 
isa proof that this timber is not ultimately capable of resisting the Teredo , 
although the bark and sap of the timber render it proof against the 
Teredo for a few years. Some authorities, however, in Queensland 
claim that this timber is capable of resisting the Teredo for a period 
of twenty years, with no other protection than the bark left on. 
In the various works carried out by me on the river Eitzroy, 
Central Queensland, I have also used the following timbers, namely : — 
Tronbark (. Eucalyptus crebra ) ; bloodwood (Eucalyptus corymbosa) ; 
red gum ( Eucalyptus tereticornis ) ; and spotted gum ( Eucalyptus 
maculata , var. citriodora) . All these timbers have been destroyed by 
the Teredo whenever from any accident the copper with which they 
had been sheathed became broken or otherwise opened out. 
THE TEREDO AND OTHER AUSTRALIAN TIMBERS. 
In order, if possible, to collect the experience of this subject 
throughout Australia, I have applied to authorities in the other 
colonies, and the following is the account I have received from 
Victoria : — 
“ The only timbers used by the Melbourne Harbour Trust 
for pile work are red gum ( Eucalyptus rostrata) and ironbark 
Eucalyptus leucoxylon) from Victoria and New South Wales, and 
grey or yellow box from Gippsland. At present there are no 
symptoms of ravages by the Teredo , but the timber has only been in 
the works for about twelve years. There are no means of protection 
of any kind used for the piles in the Trust’s works.’ ’ 
Extract from report by Commissioner Hodgkinson on submerged 
samples of timber: — 
“ I beg to submit the following brief remarks with reference to 
the piles of timber placed for experimental purposes in the water of 
Hobson’s Bay, about seven years ago, and quite recently (1888) 
taken up for examination : — 
“All of them display some indications of attack by Teredo 
naval is, but the jarrah, ironbark, Gippsland red gum, New Zealand 
totara,.and box of East Gippsland have only been bored by the 
Teredo in a few places, through thin sapwood ; the penetration of the 
matured wood having apparently been arrested by the astringent 
matter therein. 
“The piles of blue gum ( Eucalyptus globulus ), ordinary 
stringy bark ( Eucalyptus macrorrhyncJia) , head-flowered stringybark, 
messmate ( Eucalyptus obligua ), and bastard box ( Eucalyptus poly- 
anthemos) have been penetrated by the Teredo to such depths as to 
show that the timbers of these kinds of eucalyptus are liable to serious 
injury from its attacks. 
“ This remark is also applicable to gumtop ironbark ( Eucalyptus 
sieberiana ), the pile of which is not only much perforated by the 
Teredo , but is also decayed in parts thereof, and therefore shows that 
I was justified in my condemnation, about eight years ago, of the use 
