go THE RUBBER INDUSTRY 



Throughout all districts of the Amazon Valley ex- 

 traordinary tales are told of the yield from indi- 

 vidual trees, and often of whole estradas of such trees. 

 There is no doubt that the proportion of very free 

 milkers is comparatively large, especially on the prop- 

 erties more recently opened for regular work in the 

 national territories in the vicinity of the Acre, the 

 upper portions of the Purus and Jurua, the Javary, and 

 other waterways. There are many authenticated cases 

 of individual trees yielding as much as 500 c.c. in one 

 tapping, equal to half a pound of dry rubber, but no 

 reliable data is extant to show for what period this 

 rate of yield was maintained. In the districts of the 

 upper rivers it is not an unusual occurrence for a 

 collector to deliver 1,000 kilogrammes (2,200 pounds) 

 of dry rubber in the tapping season, equal to 15 pounds 

 per tree on an estrada of 150 trees; but this only 

 happens in localities where virgin trees are fairly 

 abundant. In many parts of the central section, 

 covering the Madeira and the lower portions of the 

 Purus and Jurua, the returns in a season from single 

 estradas of 150 trees frequently amount to 1,200 pounds, 

 and sometimes 1,500 pounds, of dry rubber ; but the 

 average is lowered by the very much smaller deliveries 

 on the older-established properties, as is demonstrated 

 quite clearly by the tests made during 1913. When 

 all the circumstances are given due consideration, it 

 is evident that the future of the industry is dependent 

 on the average returns, and not on any abnormal yield 

 from exceptionally favoured estates. All the conditions 

 will be altered for the worse if the price of rubber falls 

 to a point which compels a cessation of work on the 

 older properties. 



