RUBBER 489 



annual yield of dried rubber may then be approximately i Ib. per 

 tree, increasing to 2 or 3 Ib. per tree at 8 to 10 years old, and to an 

 average of 4 to 6 Ib. per tree when these are 12 to 14 years old. 

 A return of 150 Ib. of dried rubber per acre, from trees 6 years old, 

 and 400 to 500 Ib. at ten years old are considered good average 

 yields, though in many cases a much larger crop is obtained. Ten 

 trees on Culloden Estate, in Ceylon, about twenty-two years old 

 gave an average yield of 18 Ib. of dried rubber each in 1909, the range 

 being from 13 to 25 Ib. per tree. The trees increase in circum- 

 ference of stem at an average rate of 3 to 4 inches per annum, and 

 bear seed when 5 to 6 years old, producing from 2 to 3 thousand 

 seeds at that age, to about 40 or 50 thousand when 18 years old (See 

 below). The usual cost of bringing Hevea rubber into bearing, 

 exclusive of cost of land, varies from about ,20 to 30 per acre, 

 according to the nature of the land and locality, while the cost 

 of collecting and shipping the rubber ranges at present from 

 IQd. to Is. Sd. or more per Ib. The price of rubber fluctuates 

 considerably; that of Fine Hard Para rose from about 3s. 6d. to 

 9s. 4d. during 1909, reached 12s. 6d. in April 1910, with Plantation 

 smoked sheet at 12s. Wd. per Ib. Fine Hard Para is still the stand- 

 ard grade, but plantation rubber commands a higher pricet and 

 is now largely employed in the manufacture of tyres as well as for 

 the finer uses. The seeds (see foregoing remarks) are large and 

 oily, about 110 weighing a pound ; they are of short vitality, and 

 germinate in about 10 to 12 days when fresh ; for transmission by 

 post, 500 seeds \vith packing weigh about 9 Ib. 



Ceara Rubber. (Manihot Glaziovii. Euphorbiaceae). A small, 

 rather spreading, quick-growing tree, 25 to 40 feet high, native of 

 South America, introduced into Ceylon in 1877. By 1883 as many 

 as 977 acres were reported to be under this tree in Ceylon, but, 

 owing to difficulties of tapping the cultivation fell into neglect for 

 a number of years. Lately, however, with a greater demand 

 for rubber and with better methods of tapping, the trees yield a 

 satisfactory return, and the rubber is second in quality only to 

 that of Hevea. The tree is suited to a dryer climate and higher 

 elevation than the latter, but unfortunately no perfect method 

 of tapping it appears to have been yet devised. In Hawaii, 

 where Ceara rubber is largely planted, the climate being unsuited 

 to Hevea, the bark is stripped off perpendicularly in sections 6 in. 



t At the time of writing, this has suffered a seveie dro\ the -verage London price being 

 about 2s. !</ per Ib. as against 3s. 1<7. for Fine Hard Para. (October 1913) 



