Diffusion versus Double Crushing. 239 



not be exceeded. The diameter of the cells should be 

 limited as it would otherwise increase the difficulty 

 of packing tight the bottom plate, and make it bend. 

 To employ air pressure instead of water pressure for 

 the last cells has solely the obje6l of saving water. 

 Wherever there is a sufficiency of water, air pressure 

 should be entirely omitted as it increases the working ex- 

 penses and retards the process of exhaustion. Without 

 air pressure smaller draughts of juice will be required 

 whilst dilution and exhaustion remain the same. A 

 special arrangement of pipes on the battery which allows 

 of skipping any of the cells increases the safety and the 

 uninterrupted course of the work to such a degree that 

 it is well worth while making it. 



The carrying of the cane from the punts to the hoppers 

 or slicing machines is still done in a very slow and 

 expensive way, the cane being unloaded at the platform 

 by manual labour, the canes being put again by hand 

 into hoppers, but various proje6ls for the dire6t trans- 

 mission of the cane to the hoppers through mechanical 

 means have been already suggested and are sure to find 

 a satisfa6lory solution as soon as diffusion is more 

 largely adopted in this colony. 



With regard to dilution, the percentage of water used 

 for extra6ling the juice I mentioned already that it is 

 quite pradticable to keep it within the maximum limit of 

 20 0/0. I'f the grinding is to proceed regularly and with- 

 out interruption an adequate evaporating station must 

 be conne6led with the diffusion battery, as well as vtith 

 one, or better with two vacuum pans, constru£led in pro- 

 portion to the evaporating station. The choice of an 

 evaporating system depends largely on the price of the 



HH2 



