10 



THE INDIA RUBBER WORLD 



[October i, 1901. 



YIELD OF THE PARA RUBBER TREE. 



IN a report on the rubber production in the state of Ama- 

 zonas, by the British vice consul, Mr. Temple — which, by 

 the way, is the most informing report on this subject that has 

 yet appeared in print — he says : " It is not possible, in the 

 present state of the industry, to give any precise data as to the 

 average yield of laltx per tree." The examination of the books 

 of a number of rubber estates actually working, however, leads 

 the consul to estimate the average yield per tree of cured rub- 

 ber at 2.2 to 3.3 pounds per season, under favorable conditions, 

 though trees are tapped on estates where the average is not 

 more than i.i pounds. 



A recent visitor to The India Rubber World from Bolivia 

 said that he had never had reason to calculate the yield per 

 tree. If, in a given district, 25 arrobas per estrada couXd be ob- 

 tained, it was regarded as an exceptionally good yield ; when 

 it fell below 10 arrobas per estrada, the rubber hunters moved 

 away. Now, counting the arroba as 32 pounds, and one estrada 

 as 100 trees, the best rate under this estimate would be 8 pounds 

 per tree, and the smallest 3.2 pounds. But not only is the 

 number of trees per estrada variable, but the arroba is not al- 

 ways the same. The fact is, little regard is given to weights 

 except to the total, at the end of the season, and the weight for 

 which the collector finally gets credit, at Manaos or Para, is 

 less than the estimates made on the rubber " farm." 



A report made to the stockholders of the Societe Anonyme 

 La Brasilienne, on the great richness of the rubber on their 

 estate in Bolivia, mentions that a laborer can gather 40 kilo- 

 grams per fortnight from one estrada, which would figure out 

 13.2 pounds per tree, for a season of 180 working days. 



A prospectus of a rubber " farm " for sale on the river Jurua, 

 in Brazil, of 200 estradas. gives figures on the yield which point 

 to a yearly average of 15.84 pounds per tree per season. An- 

 other private estate for sale on the river Purus is claimed to 

 yield at the rate of 11.88 pounds per tree. But it will be re- 

 called that when the estate of the Visconde de Sao Domingos, 

 on the island of Marajo, was sold to the Para Rubber Estates, 

 Limited, the former owner claimed an average yield of 8.8 

 pounds per tree, though a detailed statement, made for the 

 company's prospectus, of the working of the estate for 1895, 

 figures out only 6.89 pounds per tree — always assuming that 

 the estradas embrace 100 trees each. Another company, the 

 Amazonas Rubber Estates, Limited, was " floated " in London 

 on a prospectus which indicated a yield pertree of 17.6 pounds, 

 this being on the river Teffe, above Manaos. Another "ex- 

 pert" quoted in the same prospectus, however, was content to 

 estimate a yield of only 10 pounds. But the promises of these 

 last two prospectuses have not been realized with regard to 

 profits, and presumably have not been with regard to yield. 



The English scientific observers sent to the Amazon a good 

 many years ago to study the rubber situation in connection 

 with forming plantations in India, while reporting in great de- 

 tail the methods of tapping trees and coagulating the latex, 

 singularly failed to note the rate of yield. But Mr. James 

 Collins did mention obtaining " six ounces in three days " from 

 a Hevea tree, which, counting 180 days to the working season, 

 would give izYt pounds to a tree. 



Sir Martin Conway, in a work just published, on "The Bo- 

 livian Andes," says that estimates of the rubber yield vary. 

 He found nobody counting on less than 3 pounds per tree per 

 year, and no estimates higher than 7 pounds. The law in 

 Bolivia, by the way, regards an estrada as embracing 150 rub- 

 ber trees. 



Here has been summarized about all that has been made pub- 



lic in regard to the yield of the Para rubber tree, and the reader 

 is free to form his own conclusions. To quote the British 

 consul again : " Two trees growing close together and under 

 apparently precisely similar conditions, will often vary very 

 much as regards their yield." 



More accurate data exist with regard to the yield of the Para 

 rubber tree under cultivation. In the Ceylon botanic gardens 

 the late Dr. Henry Trumen tapped one tree with these results: 



At the age of 1 1 years i lb. 1 1 3^ oz. 



At the age of 13 years 2 " lo " 



At the age of IS years 2 " 13 " 



At the age of 17 years 3 " 3 " 



At the age of 19 years 3 " o\ " 



Superintendent Derry, of the government plantations at 

 Taiping, Straits Settlements, wrote in 1897: " A few [Para] 

 trees, twelve years old, produced 3 pounds each, but in no in- 

 stance were the tappings exhaustive." 



THE BOLIVIAN COMPANY. 



y T appears that the company for exploiting rubber in Bolivia, 

 -*• mentioned by our British correspondent in The India 

 Rubber World for August i, is one which has been organized 

 through the eflforts of Sir Martin Conway, of England, whose 

 interest in Bolivian development has been referred to in these 

 pages more than once. But it does not relate, as supposed in 

 some quarters, to the Acre district, lately in dispute between 

 Bolivia and Brazil. The August Bulletin of the Bureau of 

 American Republics gives space to a copy of the contract en- 

 tered into between the Bolivian government and "The Bolivian 

 Company," the signature in behalf of the company being that 

 of George H. Bridgman, United States minister at La Paz, 

 whose interest in rubber development has been manifest in dif- 

 ferent ways of late. 



The government of Bolivia on September 25, 1900, author- 

 ized Sir Martin Conway to organize, in England and the United 

 States, a company to exploit the natural resources of the prov- 

 ince of Caupoliocan and the river Kaka, province of Larecaja, 

 as a result of which has been incorporated The Bolivian Co. 

 The government concedes absolutely 15,000 square miles of 

 territory, to be located within the region bounded by the 

 rivers Beni, Kaka, and Pando. The company shall have for 

 fifty years exemption from duties on all material imported for 

 the development of their concession. They shall deposit with 

 the government in each year one third of their net profits from 

 any source, the same to create a fund for works of public 

 utility. The company are required to send out an expedition, 

 to embrace a surveyor, a mining engineer, and a botanist, to 

 explore the country referred to, and locate the lands to be 

 chosen in behalf of the company. Meanwhile the government 

 agrees not to make concessions to other parties of any lands 

 within the region here referred to. As reported in The Indi.\ 

 Rubber World for August, this expedition has been dis- 

 patched already. 



It is believed that important mineral resources exist within 

 the district here mentioned, in addition to a wealth of India- 

 rubber. 



The working of rubber has been begun in the department 

 of Santa Cruz, in Bolivia, where the supplies of " fine " rubber 

 are reported very abundant. " Caucho " has also been discov- 

 ered in southern Bolivia. In order to facilitate the export 

 of these products a national custom house has been estab- 

 lished on a tributary of the Paraguay river, the waters of 

 which discharge successively into the Parana and the rio de la 

 Plata, reaching the seaboard at Buenos Aires. 



