9-1 



Commenting on this Report, Mr. C. W. Darley, late Engineer for Har- 

 bours and Rivers, New South Wales, who gave especial attention to the 

 subject of turpentine timber ancl cobra, wrote to me — 



There is one portion which, from long •oj^perionee and observation, I must 

 remain at issue with your conclusions. I refer to your couclushjus set forth 

 in clause V that the bark will afford protection to the piles. I had in my old 

 office a bag full of samples of, bark and wood cut from turpentine piles under 

 water, showing the worm-holes passing through the bark and into the timbel" 

 (sap-wood only) — indeed some samples rather hidicated that they had a weak- 

 ness for the bark-covered portions. It may I)e that where the bark is closelv 

 adherent they pass through, hut when at all loose they do not. I have never 

 yet met with a case when Teredo sinking in one piece of wood has passed out 

 into an adjoining piece even though in close contact — for instance, I have seen 

 dozens of defective planks removed from punts, and never detected a worm 

 passing from the bad one to those adjoining or to the planks inside. In 3-inch 

 planking the caulking would perhaps only go half-way as shown in rough 

 sketch,* having IJ-inch of wood in close contact. 



I never saw this joint crossed. May it not he the same with the hark if 

 still loose it forms .such a joint, while if it is closely adherent the worm may 

 pass as shown by the samples I had in my possession, now all lost I fear. I 

 never troubled about the hark being kept on after the piles were brought on to 

 the ground and passed. I looked to the bark as one of the means for identify- 

 ing the timber only, and I have never yet seen any difference in life between 

 those driven with or without bark. All are equally liable to be damaged as 

 far as the sap-wood goes. 



When deciding to use sheathed piles I would never think of using turpen- 

 tine, as they invariably run much larger In the girth at the butt for (say) a 

 40Tfoot pile than Ironbark, as a rule. Indeed, quite 50 per cent, larger. So 

 when sheathing is paid for at Is. 6d. per super, foot, the extra price of the 

 timber is soon covered by the saving in sheathing. 



RBrORT OX THE DURABILITY OF UXSHEATHED TURPENTINE 

 PILES FOR WHARF CONSTRUCTION. 



During the past three years, while demolishing a number of old wharves in 

 S.vdney Harbour to make room for improvements necessitated by the growth 

 of the trade of the port, we have had ample opportunity of ascertaining the 

 value of turpentine piles for wharf construction. Nearly all the old private 

 wharves in Darling Harbour were built of unsheathed turpentine piles of from 

 8 inches to 12 inches in diameter. Though the exact dates of erection are not 

 obtainable, it is well known that many of them have been standing from thirty 

 to forty years. They were usually of light construction, having been built to 

 suit a much smaller class of vessels than we find it necessary to provide for 

 now. Had it not been for the great increase in tonnage of ships in recent 

 years, several of these old wharves might have been repaired and made 

 serviceable for a few years more. Naturally some of the piles drawn were 

 found to be entirely crippled, but an examination showed that these were 

 usually not turpentine, l3ut some other timber. 



We have, in our sample-room in the oflice, four sections cut from piles 

 drawn froui Smith's wharf. Miller's Point, which, from outside Indications, 

 appeared to be amongst the most damaged of the piles, usually about low- 

 water mark. In three instances, while the sapwood has disappeared, having 

 been destroyed by Limnoria terelyrans, the timber itself is as sound as the day 

 it went into place. ' Only one of the three sections has any teredo holes, and 

 that not more than ten small ones, which would not materially weaken the 

 pile. The fourth section, which is completely riddled with holes, is not tur- 

 pentine, and has been classed as Ironbark. It may be added that about 80 

 per cent, of the old turpentine piles, which we have drawn recently after a 

 service varying up to forty years, have been used over again for various 

 purposes, such as sleepers for cargo-shed floors, repairs to old wharves; &c. 



' Not reproduced. 



