450 



THE INDIA RUBBER WORLD 



[May 1. 1914. 



hy the Lands and Mines Department for measuring the girths 

 nf the trees, and the distance from the lowest cut on the tree 

 to the fork was measured. The experiment was divided into 

 the following classes : A— trees bled by a cutlass, employing the 

 feather-stitch pattern of cutting on one-half the circumference 

 of the tree, as at present in use in the colony ; B — trees felled 

 and bled by the method employed in Venezuela, at right angles 

 to the axis of the trunk, each tree being felled at three feet 

 from the ground so that its trunk remained propped on the 

 cut end of the stump, in order to facilitate bleeding and col- 

 lecting on the lower part of the trunk, the method described 

 by Jumelle being followed as closely as possible. Trees were 

 also bled by means of V-shaped cuts with a common vertical 

 channel and by means of the herring bone system, but these 

 systems were abandoned at an early stage of the experiment 

 as they appeared to yield considerably less than the other two 

 systems. By methods A and B the approximate yield of dry 

 balata per square foot of bark bled was : .A — local method, 46 

 ounces; B — \'enezuelan, 25 ounces. 



EXPfZKIMENT TWO. 



It was then decided to experiment by bleeding standing trees 

 round the whole circumference, and by bleeding felled trees. 

 Fourteen trees were used for this experiment. Five trees bled 

 by the Venezuelan method yielded 14 pounds 2j/. ounces, or 2 

 pounds 13 2/10 ounces per tree; five trees bled standing, round 

 the whole circumference, by the feather-stitch pattern, yielded 

 15 pounds S ounces, or 3 pounds 1 ounce per tree ; four trees 

 bled standing, round half the circumference, yielded 7 pounds 

 11J4 ounces, or 1 pound 147s ounces per tree. Calculated on the 

 basis of bark bled, the results were : Venezuelan method. 25 

 ounces; whole circumference, standing, 35 ounces; half circum- 

 ference, 66 ounces. 



EXPERIMENT THREE. 



In these two experiments the trees were only bled as far as 

 the main bark, but in their report the officqcs add : "Tt was 

 obvious that the cuts could he extended above the main bark 

 of the tree on the lower part of the branches ioth in felled and 

 in standing trees." In the third experiment the trees were bled 

 in this way. Only four trees w-ere available for this experi- 

 ment. The total height of the stem and branches bled by the 

 British Guiana method was 7414 feet, and in the Venezuelan 

 method 97"/^ feet, the yields obtained being, by the former 

 method, 5 pounds, and by the latter, 4 pounds 5 ounces — an 

 excess in favor of the Briti.sh Guiana method of 11 ounces. 

 These were all the experiments made for the purpose of compar- 

 ing the methods of tapping standing trees and tapping felled 



trees. 



CONCLUSIONS. 



The officers arrived at the following conclusion : "If the re- 

 sults of tapping trees by the Venezuelan method, by the method 

 now in use in British Guiana, and by a modification of the 

 latter in which the whole circumference of the tree was bled, 

 instead of half the circumference, be compared, they show that 

 the greatest yields obtained were by the last method, and in 

 no case did the yield from the trees which were felled and bled 

 over the whole circumference exceed the yield obtained from 

 the trees which were bled round the whole circumference, while 

 standing, in experiment 2. The yield obtained from trees bled 

 liy the British Guiana method, in experiment 1, gave, per tree, 

 5 ounces less of dry balata than those bled by the Venezuelan 

 method ; in experiment 3 they gave 5J/2 ounces more per tree ; 

 in experiment 2 they gave HYz ounces less per tree. In the 

 last named it has been previously pointed out that the trees bled 

 by this system were smaller than those bled by the other system, 

 while the larger trees in the experiment have generally given 

 the greatest yields. 



"If the results of all the bleeding be taken together the yields 

 obtained per tree are : British Guiana method, 2 pounds ; 

 Venezuelan method. 2 pounds 7% ounces — a difference of 7'/i 



ounces per tree. The felling of the tree before bleeding, as is 

 done in the latter system, necessitates the employment of two 

 men, wliile one can bleed a standing tree. Felling takes longer 

 to execute, and it frequently necessitates the felling of one or 

 more of the surrounding trees, so as to allow a clear space 

 for the tree to fall. It demands the conveyance of additional 

 implements, viz., axes, calabashes or collecting vessels. All of 

 these render collection of the milk more difficult. Further, it 

 destroys the tree, the value of which for timber in this colony 

 is well known. In order, therefore, to compensate for difiicul- 

 ties ensuing in this lucthod of extracting the latex, very large 

 yields should be obtained. The experiments do not indicate liiat 

 comparatively large yields are obtained." 



THE AKEA TO BE TAPPED. 



On the question of tapping half the circumference or the 

 whole circumference of standing trees, the officers recommended 

 the former, saying : "In the hands of other than a careful 

 bleeder it luay result in the death of the tree. The tapping of 

 one-half the circuinference of a tree by the local method is the 

 most efficient system, yielding far greater returns than any of 

 the others per area of the bark bled." 



FURTHER EXPERIMENTS. 



Mr. C. \\"ilgress Anderson, forestry olficer. conducted similar 

 experiments for comparative purposes with trees in the Berbice 

 River District, with the following results: Yield of six trees 

 tapped standing, with incisions extending half way round 

 trunks, 33.5 pounds of balata ; yield of six trees tapped felled, 

 with incisions extending completely or nearly completely around 

 the trunk. 21.5 pounds — a difference in favor of the former 

 method of 12 pounds, or 36 per cent, gain in balata. "Presum- 

 ing." says Mr. Anderson, "that the trees, if tapped standing, 

 around the wdiole circumference of the trunks, would yield twice 

 as much latex as when tapped only half-way. the gain in balata 

 would then be as much as 68 per cent, over that yielded by the 

 felled trees. I may mention here that the Indians employed 

 on the work predicted a smaller return from the trees tapped 

 felled than from those tapped standing." 



The experiments demonstrate that the figures produced in 

 support of the felling method were entirely erratic, and it may 

 be taken for granted that this method will not be sanctioned 

 by the government in this colony. 



SURINAM BALATA INDUSTRY IN 1913. 



According to a report of the Surinam balata industry for 1913 

 it would seem that the production almost reached the record 

 figure of 1911. The quantities for the last ten years have been: 

 1904. 225 tons: 1905. 244 tons: 1906. 267 tons; 1907. 348 tons; 

 1908. 454 tons: 1909. 630 tons; 1910. 893 tons; 1911. 1.146 tons; 

 1912. 727 tons: 1913. 1,086 tons. 



The large production of 1913, tho slightly under that of 1911, 

 was attained by the employment of a larger number of workers, 

 while the quantity of balata was less in 1912 by reason of the 

 drought of that year. 



The area planted in Para rubber in British Guiana is esti- 

 mated at 2.700 acres. 



Of the rubber hose and other rubber goods, worth $145,930, 

 imported into Cuba during the year 1912, manufactures to the 

 value of $110,686, were from the United States; and of the bal- 

 ance, $24,169 represented purchases from Germany. 



British imports of tires for automobiles and motorcycles for 

 the first two months of 1914 amounted to £371.458. as against 

 £452.302 for the same period of 1913. Exports also showed a 

 slight decrease, amounting to £110.635 in 1914. against £142.486 

 in 1913. Re-exports increased £6.034. from a value in 1913 of 

 £32.772. 



