PARA RUBBER. 63 



too rapidly even on old trees. It is the best system to adopt 

 when it is intended to kill out intermediate trees on estates which 

 are too densely planted, and can in such instances be carried out on 

 young trees. The results obtained by this system on 10- to 30-year- 

 old trees at Henaratgoda and Peradeniya are also such as to justify 

 its adoption on old Para trees, if the operation is carried out care- 

 fully and slowly. The bark on the old trees at the places mentioned 

 has been removed at the rate of only one inch in three months, and 

 further improvements in the same direction are still possible. 



The Spiral System at Peradeniya and Henaratgoda. 



The spiral system has, in addition to all the foregoing methods, 

 been tried at Peradeniya and Henaratgoda with fairly satisfactory 

 results. It will be seen that the yields obtained at Peradeniya are 

 not as large as those reported from other parts of the island, and 

 the results at Henaratgoda are good considering the number of times 

 the trees have been tapped. The results obtained by different sys- 

 tems at Henaratgoda are given elsewhere, and from them the reader 

 may make his own deductions. The half or full spiral system allows 

 one to systematically tap the tree from above downwards for one or 

 more years, and to repeat the same operation when convenient. 

 Any system of tapping, which allows the coory to go over the whole 

 of the bark tissues on a regular plan, is to be preferred to the old V 

 or single short cuts. 



I am indebted to Mr. F. Crosbie Roles, Editor of the Times of 

 Ceylon, Colombo, for the following description of the method 

 as carried out on a well-known rubber property in the south of the 

 island : — 



The Method of Cutting. 



" The first cuts are made each a foot above the other, and in the 

 case of a tree 18 inches in circumference the groove would go nearly 

 round the stem. For trees 30 inches in circumference two lines of 

 cups on opposite sides of the tree would be required, and a tree 54 

 inches in girth would take three lines of cups. The first cut is made 

 with a knife used much like a plane ; and the second knife is used 

 thereafter day by day for paring off the edge of the groove originally 

 made. One month's tapping with the original knives made the 

 groove two inches wide, so that the whole bark area would be cut 

 away in the course of the year's work, assuming that the tapping 

 were carried on throughout the year in alternate months. The 

 cutting face of No. 2 knife, however, has been reduced to the 16th of 

 an inch. This reduces the bark area cut away in a month from two 

 inches to one inch. A third instrument has been invented for use 

 in this process. It is in the form of a circular pricking instrument, 

 which is used to penetrate to the cambium at the edge of the pre- 

 vious cut. This is done alternately with the cutting and is 

 believed to free the inner bark from any accumulation of latex. 



