92 MANUAL FOE SUGAR GROWERS. 



pressure in bags : at first linen bags were filled with 

 the scum and pressed in various modifications of the 

 presses used for cheese or cider making in England ; 

 these, although troublesome, yielded a fair quantity 

 of cane-juice, and if carefully worked and kept clean 

 did good service. 



These presses are now entirely superseded by the 

 various kinds of filter-press so largely used in al- 

 most every industry where filtration is necessary. 

 The filter-press consists of a series of chambers, 

 usually of iron. Each chamber is lined with a 

 cloth. The substance to be filtered is forced into 

 the chambers until they are all completely filled 

 with compact and nearly dry solid matter, the fluid 

 portion having meanwhile escaped through the cloth 

 into suitable channels provided for it. The cham- 

 bers are thus filled either by means of a pump, or 

 preferably by means of the aj)j)aratus known as 

 a monte-jus. This consists of a strong closed iron 

 vessel provided with a pijDe passing nearly to the 

 bottom, and leading to the chambers of the press. 

 A second smaller pi23e just reaching through the 

 top connects the vessel Avith a steam boiler. A 

 third opening provided with a stop cock serves to 

 admit the scum. The scum is run in until the 

 monte-jus is nearly but not quite full ; steam is 

 turned on, and the pressure of the steam forces the 

 scum up the outlet pipe into the chambers, the 

 pressure obtained being the pressure of the steam 

 in the boiler. A pressure of from twenty to fifty 

 pounds per square inch is found suitable for the 

 working of filter-presses for cane-juice scums. 



