264 



make up the numbers. The trees which had made experiment 2 in 

 1904 only, were not all treated alike, — this not by varying the 

 tapping but by deferring it in the case of a part of the trees so that 

 the resting intervals became unlike. 



There was, however, an experiment in tapping, which was called 

 7, but which will be called Experiment U here to distinguish it from 

 a later experiment 7. Experiment U was an attempt to estimate the 

 relative values of daily and alternate day tapping, and is to be 

 regarded as the conclusion of the experimental work of ICO4. 



But besides the working of these trees by Mr. Derry into a 

 tapping rotation, there was other tapping done in the Plantation in 

 the early part of the year. In the first place Mr. Ridley tapped 

 about 24 trees for various purposes ; and in the the second place, Mr. 

 Burgess, then Government Analyst in Singapore was allowed the 

 free use of a considerable number of trees, whence he drew latex for 

 experimental work in factory processes. There is no record of the 

 way in which these trees were tapped, but reason to believe that new 

 tapping tools were used and designs of cuts were tried. 



Tapping knives were not used as far as is known, in Mr. Derry's 

 tappings of the year; but the tapping was done as before with the 

 pruning knife and chisel. The Cevlon Gardens at the time were using 

 tapping-knives, for Mr. Herbert Wright who was then in charge of 

 rubber work at Heneratgoda, which he had systemntised in October, 

 1904 {Tropical Agriculturist, xxv., 1906, p. 309), was employing the 

 Northway-Bowman knives in his tapping. And already on the 

 Culloden Estate on seven trees from 1891 "every known method 

 of tapping" had been tried (Tropical Agriculturist, May 2, 1904, 

 p. 764). The first record of the use of tapping knives in the 

 Singapore Botanic Gardens in Mr. Derry's experiments was early in 

 1906, when several sets of this particular knife (the set is of three 

 knives) were procured from Ceylon, and tried, but it is believed with- 

 out finding favour; and when a little later a tapping knife, was 

 •definitely adopted in the Singapore Gardens, after various trials, it was 

 of the farrier's knife pattern as described in the following statement * 

 by Messrs. Ridley and Derry, (Agricultural Bulletin of the Straits and 

 F.M.S., v., 1906, p. 460)." The implement capable of making the 

 cleanest and quickest incision is the ideal one. This we have found 

 in an English .... modified farrier's blade adjusted by a screw 

 in a sliding socket .... Nearly all invented knives or tools have been 

 experimented with at the Botanic Gardens ; some have been found 

 unhandy, others unsuited for coolie use, and some much too 

 fragile." 



The application of the farrier's knife to rubber has a k^ng record. 

 As foi- back as 1872, ColUns had described and figured a- form of it 



• The statement occurs in the report on the Tapping experiments of 1905, but was written 

 towards the end of 1906. 



