MACHINERY AND MANUFACTURE 189 



would be apt to ferment and develop tackiness, and are there- 

 fore best removed from rubber which is not intended to be 

 smoked. 



It should be understood, however, that this removal in- 

 volves an appreciable reduction in the ultimate weight of the 

 product obtained. In the manufacture of sheets for smoking 

 the loss is not nearly so great. It might surprise some 

 managers if they realized what the total difference amounted 



F'iG. 49. Robinson's Washing-mill, Belt-driven. 



to in the course of a year. If we take it at i per cent, we shall 

 not be very far astray, and with rubber at four shillings and 

 twopence per pound the difference is equal to one halfpenny per 

 pound. To look at it in another way, if the annual crop of 

 rubber is two hundred thousand pounds, the i per cent, loss 

 or gain is equivalent to two thousand pounds of dry rubber per 

 annum at least. 



The usual practice is to pass the coagulated latex three 

 times through this macerating-mill before removing the rough 

 sheets to the creping-mill. This creper is also a macerator type 

 of mill, but the cutting on the rollers is on a smaller pattern. 



