CULTURE OF THE SUGAR BEET. 139 



is iii this way saved. Before the second pressing, the pulp may be mixed 

 with a small quantity of water, and such treatment has been found of 

 great advantage. But even without this treatment it is claimed that 

 the loss of sugar in the pulp amounted to only 0.825 per cent, of the 

 weight of the beets worked. 



Each of the filter presses has a capacity of 40 tons per day. and each 

 Lalouette press the pomace of 15 tons of roots or the pulp of 30 tons. 

 The system requires no handling at preparatory presses, filling of sacks. 

 &c, and, it is claimed, requires only about 40 per cent, the number of 

 laborers employed with the ordinary hydraulic press, increases the 

 yield of sugar, and reduces the yield of pulp to 17 to IS per cent, of beets 

 worked. 



The filter presses referred to vary in design according to the maker or 

 inventor, but all are based upon the same principle of a series of gridiron- 

 shaped frames, the faces of which are covered with a filtering surface oi 

 linen or jute cloth. These frames are arranged parallel to each other 

 upon a strong support, and are brought into close contact by means of 

 a screw-press fixed to one end of the support. The material to be filtered 

 is forced between the frames through a passage along the side or through 

 the center and distributes itself over the filtering surface; the liquid por- 

 tion finding its way into the interior of the frame is drawn off at the 

 bottom by means of a stop-cock attached to each one, while the solid 

 portion is held back between the filtering surfaces. When the press is 

 fully charged, the pressure holding the frames together is removed, the 

 frames separated, and the pulp allowed to fall into a recipient under- 

 neath. If necessary, the cloth is cleaned by means of a brush or other 

 suitable instrument. 



But the combination of the hydraulic press of Lalouette and the filter 

 presses just described is not as effective in saving labor as the contin- 

 uous presses are claimed to be. These latter seem to reduce the labor 

 required to a minimum, and, with the improvements lately introduced 

 in their construction and management, they seem to be about as effect- 

 ive in Qxtracting the juice as the other systems of presses employed, 

 and depend in principle upon the application of rolling cylinders var- 

 iously constructed.* While we do not intend entering here into detaded 

 descriptions of the different continuous presses, or other means of ex- 

 traction that have been invented and employed, we consider that atten- 

 tion should be called to them on account of the interest that has been 

 manifested concerning them among the sugar manufacturers of France, 

 and that brief notices of them here will be of value to those desiring to 

 enter into the manufacture of beet-root sugar in the United States, or 

 as a source of preliminary knowledge, at least, to those who may be in- 

 terested in the progress of the industry abroad. 



The cylinders of these presses are constructed either with apertures 



* "With the exception of the Pierou screw press. 



