Gums, Resins, 



[Dec. 1906. 



Tapping on that principle they had gone approximately round one-half of the tree, 

 and a mean average yield of 3 lb. of dry rubber per tree. The long spiral gave 3 lb. 

 5 oz. and the half spiral 2 lb. 8 oz. That only showed the yield per tree, but they 

 were trying to work out the yield per unit of bark excised. 

 Mr. Greig : — What angle is this tapping done at ? 



Mr. Wright :— The tapping was supposed to be done at an angle of 30 to 45. 

 This system of tapping gives us three lb. of dry rubber in a year, and can be 

 continued for 4 to 6 years. 



Mr. Cameron :— Does that afford ample time for the bark to become renewed ? 



Mr. Wright I think six years would be ample time to allow for bark 

 renewal. 



Mr. Parkinson Starting ou a smaller tree, however, your surface would 

 not last so long ? 



Mr. Wright mentioned that the rate would be the same; and pointed out 

 that the whole of the work had been done by Sinhalese coolies. 

 Mr. Parkinson :— And jolly well done, too ! 



THE HALF SPIRAL. 



The party then proceeded to the trees marked B. They would notice, Mr. 

 Wright remarked, that of the three systems they got the least rubber per tree in a 

 given time by the half spiral system, and they had approximately gone round half 

 to one-third of the tree. They could see on the tree where the Northway pricker 

 had been used. 



Mr. Parkinson :— Might I ask what tapping knives were used? 

 Mr. "Wright :— The Bowman-Northway and Miller knives were used on the 

 trees A, B, and C. 



the full spiral. 



Passing on to the trees marked A, Mr. Wright remarked that this was the 

 fvdl spiral tapping which, worked at the same rate, would go completely round the 

 tree in three years. In some parts of the island they had adopted the spiral system 

 and had completely stripped the cortex in a year. He thought it was a dangerous 

 system to work. They could hardly expect the tree to stand being stripped of its 

 entire bark so rapidly as once per annum. 



THE EFFECT OF THE PRICKER, 



Mr. Grieg :— When the pricker goes into the cambium, it raises a lump. 



Mr. Wright .:— The pricker does touch the cambium ; but I have peeled away 

 a large piece of bark, and have been rather surprised to find there was practically 

 no bad effect, although I expected there would be. Very often, however, with the 

 rotating pricker the coolies work up and down the cut macerating the whole of the 

 tissues. I have not seen any very bad effects from the pricker when properly used. 



Mr. Greig :— But does it not raise lumps ? I have seen lumps raised by the 

 pricker touching the cambium. 



Mr. Wright : — You will see the effect of the pricker here. We find it an 

 advantage to leave as much bark as possible on the tree, and reacli the latex tubes 

 by means of the pricker. I have seen a case where the paring was done very 

 deeply, and where the cool y had gone very near, but not quite to the cambium; 

 when the dry weather came, the bark peeled away, and the borers got in. You get 

 it Avorse in Geara than in Para, for— as you know — the bark of Ceara peels away 

 much more easily. 



a remarkable stump. 

 Mr. Wright then led the party to a remarkable Para stump cut 3 feet or 

 4 feet from the ground and cemented over the top. "This," said Mr. Wright, "is 

 rather an interesting old stump. It is another of the trees which were tapped lightly 



