35 



gold medals went to the Bawraan-Northwav and Miller knives, 

 both of which are simple, keep sharp, and p ire thin shavings with 

 out any dragging of the cut edges. It is very important that the 

 shaving should be thin, as the bark should be made to last about 

 four years before it is all cut away, in order to allow the renewed 

 bark time to ripen fully. 



The yields obtained on some estates have been phenomenal, 

 but it is probable that in many of these cases the bark has been 

 too rapidly cut away, and that a period of waiting for the renewed 

 bark to ripen will ensue. It is not as yet safe to count on more 

 than a pound a year a tree, if so much, but even this means 150-200 

 lbs. an acre, an amount sufficient at present prices to yield an 



Hitherto the Ceylon rubber has mostly appeared upon the 

 market in form of " biscuits "—flat pancakes about 10 inches in 

 diameter. The Malavan has mostly been in - sheets " about two 

 feet long. But both these forms seem destined to disappear in 

 favour of block— rubber prepared by blocking the sheets, biscuits, 

 or other form under high pressure. Some samples of block were 

 shown by Lanadron Estate, Johore, and similar samples have 

 lately been getting the highest prices on the market. 



The Ceylon and Malayan rubber has been obtaining higher 

 prices per pound than any of the ' wild ' rubbers, even ' fine Para ' 

 the standard of the market, but pound for pound of pure rubber is 

 really getting lower prices, for the Para rubber contains about 

 20 per cent of moisture. Why this should be so is one of the 

 greatest problems before the investigation at the present moment. 



Anyone comparing a sample of fine Para with one of any 

 plantation rubber— Ceylon, Malayan, or Mexican— can see at once 

 that the former is more springy, returning more readily to its 

 original shape when stretched. The higher price really obtained 

 tor this rubber may therefore probably be explained on this con- 



«ow is it because the trees are young that the rubber is 

 weaker or because the rubber is not smoke-cured ? Is it because 

 me rubber is in biscuit or sheet instead of in blocks? Is it that 

 is too much dried (Para rubber contains 20 per cent of moisture) ? 

 »s >t that it is too pure and too much washed ? Or is it that it is 



tio n coagulate - d in the best wa y ? A11 these ' sin » 1 y or in combina - 



n » are possible explanations, and there may be others, 

 that -f here is no doubt that older trees & ive stronger rubber, but 

 to S tV'T tHe ° Mest trees in Ceylon— 30 years old— is not equal 

 the <° ^ m erican rubber. Smoke-curing (without coagulation at 

 beside^ tlmG - S6e - mS t0 stren ? then the rubb er, and block rubber, 

 oxidaf^ ltS sav * n g" m cost of freight, and exposure of less surface to 

 "ruLt * S6ems actua % stronger than sheets or biscuits. The 

 do with ^ GSS J 0f the P lantation ™ bber ma y also have something to 

 institute and L ex P eri ments are now being tried by the Peradeniya 

 uuon in the preparation of block from wet biscuits. 



