90 



That cobra is much more active in attacking turpentine in tidal waters, 

 ■where salt and fresh water mix, than in pure salt water. 



To the '2nd Question, — Are there two varieties of turpentine timber, one 

 cobra-resisting, the other not? 



Our answer is. that there are two turpentines of the same species, called the 

 black and the red, but, although frequently no sufficiently sharp line of demar- 

 cation exists between the two timbers for us toi single one variety for special 

 commendation, we would prefer typically red turpentine. There is also a 

 ■brush turpentine, whose botanical name is Bhodnmiua trlnerria, somewhat 

 similar to true turpentine, but we found no evidence to show that it had been 

 substituted for true turpentine, and we failed to find any inducement to 

 timber-getters to do so. 



To the 3rd Question, — Have any other timbers been substituted for turpen- 

 tine and used for piles, &c.? 



Our answer is, that we found no evidence that such is the case. Further, 

 we failed to find any inducement to suppliers to do sO, as turpentine is very 

 plentiful in the coast districts. 



We recommend, — 



(0) That in pure salt water, in special instances where it Is known that 

 cobra is not very active, also in very foul salt water, such as around 

 ' Pyrmont and Glebe Island bridges, the use of turpentine piles be 



continued, providing they are driven with their back attached and 

 uninjured. In cases of outside piles, exposed to the friction of the 

 sides of vessels, some protection or guard should be adopted to pre- 

 vent damage to the bark of the piles. 



(&) That where turpentine piles are specified to be with the bark on, tlie 

 condition should be rigorously enforced, piles found to show defect in- 

 the bark below high-water mark being condemned as unfit for use. 



(f) That turpentine piles be, as far as possible, felled when the sap is 

 down, and the bark closely adheres to the log. 



(d) That in unpolluted tidal waters, turpentine piles be protected by 

 metal sheathing. 



Speaking more generally, and taking into consideration the fact that turpen- 

 tine is not absolutely resistant to cobra, and the very great expense the Depart- 

 ment of Public Works is annually put to in replacing cobra-infested timber, we 

 recommend that for the future the use of turpentine timber, either wltli or 

 without bark, or in squared or sawn sizes, when placed in any position in 

 which cobra is known to be active, should be discontinued in the public works 

 of this colony, unless it is absolutely protected throughout its entire face and 

 ends by copper or some other equally satisfactory protective covering. 



We would recommend the sheathing of turpentine piles, without any excep- 

 tion whatever, if the question of expense did not stand in the way. and the 

 only exceptions we recommend are those of piles on the coast and in parts of 

 S.ydney Harbour, as already stated. 



The cost of coppering piles, or rather the increase of the practice of copper- 

 ing piles, will at once claim attention; but we would observe that the expen.^e 

 of the piles themselves is not the only consideration. If they are eaten through, 

 the superstructure may have to be replaced, perhaps at a cost many times 

 exceeding that of the piles themseh-es. The matter of the life of a pile involves 

 other considerations tlian that of the durability of a post in fencing which 

 carries no superstructure. 



Turpentine is plentiful in most of the coast forests of New South Wales, It 

 Is essentially a pile timber, growing as it does in suitable sizes, straight and 

 even in the barrel, and up to 90 ,'uid 100 feet in length, and it is the cheapest 

 class of hardwood ])rocurable in the round in the colony. If the timber be 

 coppered there will be no necessity, except In rare instances, to use coppered 

 Ironbark for piles, and the drain on ironl)ark for this particular work will be 

 v«ry largely reduced. We desire to encourage the use of turpentine for piles, 

 but subject to all the precautions we have indicated. 



