THE SEPARATION OF THE CRYSTALS 



425 



(3553 of 1874) specifies the use of two gutters and of a casing, interior to 

 the curb or usual outer casing, and capable of being raised in a vertical plane. 

 Material caught on this casing is delivered to one gutter, that intercepted 

 by the curb when the interior casing is raised passing to the other gutter. 

 This principle is contained in various later patents, that of Patterson (22384 

 of 1897) being indicated in Fig. 267. The use of individual gutters alone 

 appears in patent 11842 of 1897, Fig. 268, granted to Lubinski and Krajewski, 



Fig. 269 



bit, the absence of a second surface to receive the purer runnings leads to 

 an imperfect separation. 



In Matthewwissen's patent (24993, 1901) vanes are formed in the curb, 

 and the direction of rotation of the basket is changed when washing begins, 

 the flow of the molasses being directed to independent gutters by the vanes. 



MacFarlane's patent (26716, 1902) employs an imperforate cone-shaped 

 basket separated from the screen. The molasses projected on to the inner 

 wall drain off vertically, and are directed into one of two gutters according 

 to the position of a cylindrical screen, the arrangement of which is adjusted 

 by the operator. 



Another more complete and preferable scheme is that of double curing. 



