Bucnanan.—On Charring Timber as a Protection from Teredo. 185 
Letter from Mr. Watson to the Hon. Mr. Waterhouse relative to the 
charring of timber :— 
« Hobart Town, June, 1876. 
« Sir, —Believing that you take an interest in all matters connected with 
the prosperity of New Zealand, I take the liberty of addressing you on a 
subject of considerable importance to the colony—namely, the construction 
and maintenance of her harbour works. 
‘For some years past I have continually heard of the destructiveness of 
the ship-worm to the piles forming the wharves and piers; but I was 
rather surprised on reading a small publication compiled in New Zealand 
in 1875, and containing reports of several gentlemen on the durability of 
New Zealand timber, to find the immense expenditure to which the Govern- 
ment have been subjected in consequence of the damage done to the 
piles by these worms. For the last seventeen years the Hobart Town 
Marine Board, at my suggestion and under my superintendence, have had 
the piles used in the construction of their works put through a process of 
charring, and have found it to answer admirably. Some seventeen years 
ago I was employed by the Government here to superintend the building 
of what is ealled the New Wharf, in this harbour (the old one, which had 
been erected about fourteen years before, having been quite destroyed by the 
ravages of the worms on the piles). The plans, ete., for its erec- 
tion were all prepared in the Public Works office, and it was intended to 
have all the piles to be used in the construction of the wharf coppered ; 
but on an estimate of cost being made the intention was abandoned. I then 
proposed a plan which, from my experience, I considered would answer the 
purpose of stopping the ravages of the worm—namely to char the piles, 
the expense of which is not more than ten shillings a pile. This being a 
new process, and apparently so simple a remedy, it was not at first enter- 
tained by our engineering department, and the contractor had orders to 
proceed with the construction of the wharf. They had driven about six of 
the new piles well coated with coal tar, when on my examining one of the 
old piles when drawn out, T found it was charred, but on one side only. It 
had evidently been a fallen tree, and a bush fire had passed over the upper 
side of it, the other side being most likely embedded in wet scrub, or in the 
ground. The charred side was quite perfect, but the worm had completely 
eaten away the other side of the pile. On this being brought before the 
department, instructions were at once given to the contractor to char all 
the remaining piles to be used in the work. I am forwarding you two 
samples of portions of piles taken from that wharf, on which I will note 
particulars. One is a piece of the first pile that was driven without 
charring, the other from a pile which was charred and driven a week or so 
x 
