128 AGRICULTURE IN THE TROPICS [?T. II 



swamps soon die. In suitable places the trees grow rapidly, 

 increasing in girth at about four inches a year, and when they 

 girth two feet they are usually tapped. Many systems of tapping 

 are in vogue, and no one system has as yet established itself 

 as the standard. The two favourite methods at present are the 

 herring-bone and the half-spiral. In the former, a groove is made 

 down one side of the tree, with lateral grooves leading into it ; 

 in the latter, a spiral groove is made round half the tree, and 

 others parallel to it. In both cases metal cups are fixed at the 

 bottom ends of the grooves. Lately a new method of tapping, 

 by simply cutting a large Y on one side of the bottom of a tree 

 (this is based on the fact proved by Mr Parkin that much more 

 latex flows from the lowest 12 inches than from any above) and 

 renewing the wound by paring, is coming in, as it requires 

 much less labour. It was first tried by Mr Pears, and is being 

 extensively experimented with by Mr Kelway Bamber in 

 Ceylon. 



Tapping in the early days of the rubber industry was by 

 means of a hammer and chisel, but now various knives are used, 

 which shave off very thin portions of bark. There are a great 

 number of such knives upon the market, but none can be called 

 absolutely satisfactory. The cut is opened first of all, and then 

 the wound-response is obtained by shaving off a thin portion of 

 bark at intervals. Lately, however, there is a certain reaction 

 against this continual shaving, and several good estates open a 

 new cut every second day. The milk is collected in the cups, 

 and brought into the , factory, where it is coagulated into 

 biscuits or sheet in metal vessels of suitable shape. The 

 sheets or biscuits are sometimes exported as such, or they are 

 made into blocks, wet or dry. 



Latterly, machinery is coming in rapidly for treating the 

 much larger amounts of latex that have now to be handled. 

 One favourite form in which rubber is turned out is crepe, 

 which is produced by a machine that rolls the clot between 

 rollers moving at different speeds, and turns out a long ribbon 

 of crinkled irregular stuff. The crepe may be dried in vacuo 

 and turned into block. 



The growth of the rubber export from Ceylon will serve 



