Janl-arv 1, 1911.] 



THE INDIA RUBBER WORLD. 



129 



THE DA COSTA COAGULATING SYSTEM. 



A^IACHIXE which is attracting widespread interest ;imong 

 rui;ber planters in the Far East is that invented for the 

 coagulation of rubber latex by Mr. Jose Sinao Da Costa, of 

 Para. Its design is to make practicable by simple mechanical 

 means the native process of smoking the latc.x of Hcvca 

 Brasilicnsis practised by the natives in the Amazon region. It 

 is well known that the latex from tlic Para trees will coagulate 

 by the action of heat. It is known that fairly large samples of 

 rubber were produced in Brazil coagulated by other means than 

 smoking long before the Eastern rubber industry was founded. 

 Nevertheless it is still regarded in Brazil that by smoking alone 

 can be obtained those lasting properties of resiliency and tensile 

 strength, which are the denominating characteristics that have 

 gained for the product of Hcvca Brasilicnsis its supremacy among 

 rubbers. 



Mr. Da Costa, who has spent practically a life time in the 

 Amazonian rubber interest is among those who believe in the 

 virtues of smoking rubber, and he has patented this process with 

 a view to making it more economical than the native smoking 

 method, and particularly for the plantations of Ceylon and 

 Malaya. As is well known, the best prices for plantation prod- 

 ucts arc now olitaiiied for "snMkod slice!." 



D.\ COST.\'s P.\TENT L.\TEX Co.\C.UI-.\TOR. 



The operation ef this process is simple. The latex, when 

 brought from the trees, is first strained, if it contains mechanical 

 impurities, and is then poured into the coagulating tank on the 

 top. steam having in the meantime been raised in the boiler 

 below from a tire of forest woods alone. On this wood fire are 

 then thrown green palm leaves, nuts, or any green twigs, the 

 distillation of which produces acetic acid, whilst the fumes of the 

 green foliage contain creosote to some extent. The fumes are 

 collected in a special chamber, and, after being cleared of dust, 

 etc., are forced into the coagulating tank by a steaiTi injector. Dur- 

 ing the agitation thus caused the smoke thoroughly permeates 

 the latex, and in about ten minutes, or rather more, according 

 to the quantities to be dealt with — the caoutchouc globules 

 coagulate and separate, and at the same time rise to the surface. 

 After being allowed to cool of? in the tank, the coagulated rubber 

 is taken to a small press and turned out in the shape of flat 

 l)lock rubber, which is afterwards reblockcd into cube form, and, 

 after being dried, is ready for shipment. 



The Da Costa system is manufactured by David Bridge & 

 Co., engineers, of Castleton. Manchester, England. It was 

 exhibited by them at the late Exposition Universelle at Brussels, 

 where a practical illustration of it was given. Late.x was coagu- 

 lated there by the Da Costa system and then put through the 

 ■other various machines manufactured by the Messrs. Bridge, with 



the result of obtaining rubber in crepe, sheet, and block forms. 

 It may be mentioned, by the way, that Messrs. Bridge were 

 awarded the Diflome dc Grand Prix at the Brussels Exposition, 

 for rubber preparation machinery. They have prepared a hand- 

 some souvenir book illustrating and describing the various forms 

 of apparatus which were embraced in their Brussels exhibit. 



BRITISH GOLF BALL PRICES. 



IX answer to a complaint on the part of many golfers in Eng- 

 *■ land at the price of golf balls — stated generally at 2s. 6d. 

 [= about 60 cents] — a writer in London Field says that the ad- 

 vance in prices some time ago was not made until fine Para rub- 

 ber had reached l\s. [=$2.67K'I, although the makers had been 

 working at a loss for some time. The writer continues : 



"In common with others, we expected the price to fall before 

 it did. and so the old state of things might have been maintained. 

 \Ve cannot buy our rubber thread in the market one day and 

 make it into cores the next. We have to provide for the future 

 and safeguard ourselves against contingencies, and therefore, like 

 others, we have to make long contracts ahead. The contracts 

 which we made with rubber fairly high are still running, and 

 will do so for a few more months, and until they expire the cost 

 of manufacture is as great as ever. In the existing circumstances 

 it is impossible for us to reduce the price and make a fair profit 

 for ourselves ; in fact, a reduction to the 2,9. level at this moment 

 would mean loss to us. 



"Unthinking people say that rubber is 6s. [=$1.46] a pound, 

 and then they weigh a golf ball and calculate accordingly how 

 many may be made from a pound of rubber. But the cores of 

 these balls are made from fine rubber thread, and the price of 

 this at present is not 6^., but 10.c. 9rf. [=$2.6154] a pound, and 

 one poimd will only make thirteen balls. [This figures at a little 

 over 20 cents per ball for rubber alone. — I R W] It must be re- 

 membered also that, owing to the severe competition and the 

 greater care that is now exercised in the process of manufacture, 

 the cost of making is more than it was. There are innumerable 

 small expenses, which together are considerable, of wdiich the 

 public knows nothing, or, knowing, takes no account." 



"The manufactory expenses," continues The Field's corre- 

 spondent, "should surely be laken into the reckoning, but the 

 thoughtless public that talks about the possibility of making first- 

 class balls for a shilling or 18 pence considers only the cost of 

 raw material, and not all of that. The effort among leading 

 manufacturers to produce better and better balls is such that ex- 

 perimentation has to go on constantly, and sometimes it is ex- 

 pensive. Then as a specimen of working expenses that are 

 never considered outside, there is the fact that a mold, that will 

 only contain one ball at a time, and which does not last for more 

 than a year, costs us SO shillings. A very serious item also is 

 that, owing no doubt to the difficult situation in which the smaller 

 professionals find themselves, the proportion of bad debts w'e 

 make, and cannot help making, is very high — generally, as we 

 reckon, about 20 per cent. 



"The result of it all is that we cannot afford to make the balls 

 as we make them in these days, putting new and full-sized cores 

 into them and new material in every other respect, and sell them 

 wdiolesale, so as to give a small profit to ourselves, for less than 

 24s. a dozen, leaving 6d. per ball profit for the professional who 

 sells them. In existing circumstances it is utterly impossible to 

 do better than this, and we should have to stop the manufacture 

 rather than sell at a loss." 



It is interesting to note that in the report of the principal 

 chemist of the British government laboratory for the past year 

 that office was called upon to test 28 specimens of waterproofs 

 for the postoffice, in connection with the postal and telegraph 

 messengers, and materials for their manufacture, of which 23 

 were oilskins and 5 rubber-proofed goods. 



