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says that the bark of any timber, even gum, gives increased resistance to cobra ; in fact, that every tree 
will resist the pest more or less, provided the bark be intact. He is of opinion that turpentine is still the 
best, though it is far from being absolutely resistant. 
Local opinion at Port Macquarie is in favour of turpentine, mahogany, and ironbark for piles, so 
long as the bark remains sound. 
At the same time, on the Macleay River, we found turpentine piles, bark or no bark, destroyed by 
cobra in five years. 
Mr. Forester M'Donald, of Kempsey, looks upon turpentine as only effective so long as the bark is 
intact. He would prefer other timbers—ironbark, for example, and preferably old seasoned, ringbarked 
timber—to turpentine for piles. 
Mortise holes, which cut through the bark of a turpentine pile, are a common cause of mischief, 
allowing cobra free access into the timber. 
Mr. Sydney Verge, of Kempsey, draws attention to the fenders on coppered piles, by means of 
which cobra can get up into the pile by a circuitous route. This seems to us a matter worthy of attention, 
for cobra, like white ants for timber and sugar ants for saccharine delicacies, will find out the weak spots 
in the defences by an instinct that never fails. 
And now we come to a very important matter. 
We are satisfied that if round piles of turpentine are driven in cobra-infested waters, with bark 
attached and uninjured, they will resist the attacks of cobra for a period largely dependent on the bark 
remaining intact and closely adherent, but, at the same time, we deem it practically impossible to procure 
and drive any number of turpentine piles without injuring the bark more or less, and the smallest injury 
to the bai'k of the timber renders it more vulnerable to cobra. When the manner of procuring piles and 
conveying them to the work for which they are intended is taken into consideration, it is easy to see they 
cannot escape injury to their bark even under the most favourable considerations, viz., when the sap of the 
trees is down, and the bark consequently closely adherent to the log. The falling of the trees in the first 
instance, the hauling and spare chaining to the waggons, the friction of the waggon chains in road transit 
to the water’s edge, the rough handling they receive in loading and unloading on vessels, and lastly, the 
action of the pile monkey in driving the piles to their required depth, cannot fail to more or less injure and 
separate the bark. 
In the course of our investigations we saw turpentine piles, intended for Government wharves, with 
strips of bark torn off from end to end, and in some stacks we could not find a single log whose bark was 
intact. So that if the adherence of bark to the log is to be made a condition of contract, it should be 
enforced, and not dealt with as if it were a matter of slight consequence. 
VI.—Cobra and Turpentine. 
Cobra is the common name (it is an aboriginal name, see Backhouse, “ Narrative of a Visit.,’’ itc., 
p. 366) by which certain bivalve molluscs belonging to the genus Teredo , and included in the family 
Pholadidce are usually known. Teredo navalis is one of the most common and destructive species. It is 
generally about a foot in length, but sometimes grows over 2 feet 6 inches. Fourteen species of Teredo 
are known, some occurring at low water, some being found at a depth of 100 fathoms. They are very 
widely distributed, occurring from the coast of Norway to the tropics. 
In addition to cobra, what are known as “ borers ” often do a good deal of damage to piles and 
timber-work below tide mark. Those found by us at Port Macquarie are isopods, belonging to the genus 
Sphceroma, the members of which are distributed all over the world. 
We believe that no timber has absolute power of resistance to cobra. That being our conclusion, 
it remains a matter for consideration to what extent the lives of timbers (turpentine or others) may be 
prolonged. At Cundletown wharf, on the Manning River, where there is a Government punt-slip, and 
where Mr. Kenny repairs punts, boats, &c., under the direction of Mr. F. W. Baker, the Engineer for 
Roads of the district, we found pieces of turpentine a mass of cobi’a-turpentine logs, a repulsive mass 
