218 



THE RUBBER INDUSTRY 



only in comparatively few instances have separate 

 records been kept for different fields. Reliable data 

 from twenty estates scattered throughout the Federated 

 Malay States and the Straits Settlements enable the 

 approximate yield to be defined. The returns show 



The only efficient method of calculating the yield is 

 by dividing the production at each stage of development 

 by the number of acres. It would be much more satis- 

 factory if a larger acreage could be taken, but to secure 

 this result nothing short of an estate-to-estate visitation 

 would serve, and in the great majority of cases the 

 inquiry would be barren of any useful result for lack of 

 definite records on the different plantations. The cal- 

 culations of yield now made are based on returns 

 obtained from the following properties : 



