DEFECATION', PRI>"CrPLE5 OF. 289 



Preliminary Filtering. 



This may be accomplished in many ways. Many are accustomed 

 to allow the juice, as it flows from the mill, to fall into a large bucket, 

 fr<)m the bottom of which a pipe conveys the juice to the storage tank. 

 (See Plate, small mill.) This bucket is nearly filled with clean hay or 

 straw pressed closely down, by which all fragments of cane and the 

 coarser impurities are remi>ved from the juice. In larger mills the 

 juice from the mill flows through a wire gauze, with meshes from 50 

 to 70 to the linear inch, and this guaze filter is arranged as a continu- 

 ous belt, which, by its slow revolution, presents a fresh surface to the 

 stream of juice. The accumulating impurities are removed during its 

 revolution by scrubbing brushes and a tank of water through which 

 the belt is made to pass. 



Another cheap and very efiicieut filter is made by having a box 

 about 30 inches deep, 30 to 40 inches square at the top, and tapering 

 to 20 to 30 inches at the bottom. About four inches from the bottom 

 a false bottom is placed perforated with holes, and upon this coarse 

 gravel, covered by layers of increasing fineness in succession to the 

 top, which is clean, fine sand. The juice is admitted into the open 

 space below, under a slight pressure, and, filtering upward through the 

 gravel and sand, escapes by a pipe above. Pmperly constructed, this 

 filter will deliver the juice quite free from mechanical impurities. In 

 case the filter becomes stopped up, the fluid contents may be removed 

 by a stop-cock, which is inserted into the open space at tl)€ bottom, 

 when a pail or so of water will wash out the accumulated impurities. 

 This filter should be thoroughly washed with water when not in use, 

 and a little lime should be added to the last washings in order to avoid 

 fermentation. 



A convenient and effective filter may be prepared by taking an ordi- 

 nary grain bag, holding 2 bushels, and splitting it lengthwise, then 

 stitching each half into a bag equal in length to the original but of 

 half the width. Into each of these an entire bag may be inserted, and 

 the upper edges of the two "bags sewed together. The inclosed bag 

 will thus be compressed into a series of folds, and in this way present 

 an increased surface to the juice to be filtered. It will be found an 

 advantage to pack the inner bag as full as possible with fine, clean 

 hav, which will greatly assi-t the filtering by keeping the surface of 

 the bag from being stopped up by the impurities filtered out. 



F»)r convenience, four such filtere may be fastened to a frame, and 



placed in a common barrel, with a stop-cock at the bottom for draw- 



in^r off" the filtered juice. These, and all other filters, should be fre- 

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