208 THE RUBBER TREE BOOK 



they can always dry their rubber in their drying-sheds and turn 

 out a better quality of rubber. Others take quite an opposite 

 view. In any case hot-air drying-chambers are a very great 

 convenience and enable rubber to be turned out with very 

 considerable dispatch. 



As the demand is now large, most of the large firms 

 who cater for the rubber-growing industry make such driers. 

 The driers are now made to use oil-fuel when desired. This is 

 a great benefit to many estates where other fuel is scarce and 

 expensive. Oil can be readily purchased at moderate cost in 

 all Eastern lands where rubber is grown. At the same time it 

 ought to be stated that oil-fuel driers are very much more 

 expensive to operate than those which use timber or coal. 

 Four gallons of oil-fuel per hour for a drier makes quite a 

 serious addition to expenses. Improvement in construction 

 is called for and should not be unattainable. 



A drier to deal with 150,000 Ibs. of rubber per annum costs 

 about 250, to which have to be added the costs of erection, 

 say 30. 



Vacuum driers are in use on some very well-known large 

 estates, turning out a high quality of rubber. The principal 

 objection to their use is that they almost inevitably demand 

 the attention and constant presence of competent, trained 

 engineers to operate them. On small estates this is not con- 

 venient. Two types of these driers are illustrated here. 



