c. Bonnet:Ws rasper.—Fig. 1314 shows a side view of the apparatus, and Fig. 1315 a book view of tho frame of sawa. a is the rack in which is placed the bundle of °anus to be cut; a frame carrying a number of parallel saws c. The lower end of each saw has a rod d passed through it, and the saws are kept apart by distance-pieces slipped on to the rod and interposed. The upper (lids of the saws hook over a rod e, and are similarly kept apart; they aro clamped and held by the screw-nut f acrewing oe to the end of the rod. The lower end of the saw-frame is jointed to rods, free to move to and fro in guides iu the direction of the arrow. The upper end is joioted to a crook g, to which a revolving motion is given. The saws will thus alternately move through the cradle, out through any canes placed in it, and move back into the position shown by the dotted line .r-y, so as to be ready to act upon a fresh bundle of canes. Wheo the conchae been rasped to shreds, it is reduced to pulp by disintegrating apparatus, and then the juice is separated by pressure. The predecessors of this plan were Manfold'e sawdust metlaod aud Murdoch's sybteui. of cutting obliquely and disin tegrating.
Maceration.—It has been sought to facilitate the extraction of the juice by submitting the eane to the actioo of water or steam, either before the crushing operation iu the roller mill, or at an inter mediate stage between two such crushings. It seems to be undecided whether the saturation or the extra crushing should be credited with the increased yield of juice. Probably both assist ; but it has been stated that the return of juice la raised from 60 per cent. to 73 per cent. by previously slicing tile canes longitudinally, without any application of water or steatn.
Several methods have been devised for carrying out the saturating process on a practical scale, known as " maceration " or " imbibition " processes. The most important of these is Duchassaing's, shown iu Fig. 1316. The mill a meek cs the canes and crushes them, giviog 68 per cent. of juice. The begase falls upon an endless cloth b, which conducts it to a se cond mill e ; d is a tank containing boil ing woter ; e nre tubes terminating in pipes f parallel to the endless cloth, which spriokle water from the tank d npon the begass passing from the first to the second mill ; g are beaters which turn the begass and thus equalize the imbibi tion ; A is a tank which receives the juice from the mill c ; i ie a mode-jos which sends thie juice, if its density ie not suffieiently great, into the tank d, to serve for a second maeeration of new begase, or, if it is dense enough, by the joint k to the defecation. The eudless cloth b dips so that the portion between q r immerses the begass in boiling water contained in the vessel m n o p, thus iocreasing the maceration. Since the
apparatus has come into extensive use, it has been simplified by dispensiog with the beaters g and the vessel m n Ja. The system raises the yield of sugar from 9.40 per cent. on the cane to 11.04 per cent. ; it received an award of 4000/. from the General Cuuncil of Guadeloupe in 1876.
It may be mentioned on the authority of Col. Thoinas P. May, the well-known American author, who was formerly a large sugar-planter in Louisiana, that auxiliary mills (double crushing) have given highly satisfactory results in Louisiana during the season just ended (1881-2). These mills are being erected by Lee& & Co., for over 50 years the laigest makers of sugar-machinery in that state. Five rolls are the number adopted by this firm, and, on tho Poydras plantation, oue of these mills yielded the unusual result of 126 lb. of sugar from 1 tou (2000 lb ) of canes.
Diffusion.—All the processes hitherto described for extracting the juice from the cane have depended for success upon the more or less complete rupture of the juice-containing cells. "Diffusion " differs from them essentially, in dispensing with the breaking up of the cells, and the maohinery required therefor. The chief development of tJ3e diffusion process has been in the beet-sugar industry (see pp. 1842-6), but several methods of applying it to cano have been introduced. The cane is even said to possess an advantage over beet with regard to diffusion, in that the nitrogenous matters are so placed in the secondary cells that water at a high temperature can be used without injuring the membrane.
Slicing-machines.—The first operation is to reduce the cane to diagonal slices 3-4 in. long, and It-d- in. thick. One of the most successful machines for this purpose is that made hy A. Jouin et Cie., Paris, extensively used in Guadeloupe, and shown in Figs. 1347-1350. It consists of a disc, the periphery of which, formed like a truncated cone, either simple or double, is armed with a series of blades, whose indination with that of the periphery is such that the sliced matters are driven by centrifugal force away from the wheel. A pair of feed-rollers, placed in front of the disc, pass forward the canes to be cut, at a speed proportioned to the capacity of the machine, and the thickness of slice desired. The apparatus is supported on a foundation-plate, fixed to the ground or the floor of the works. A suitable cover surrounds the machine, to prevent the slices being scattered, and make them fall into the pit below, whence they can be withdrawn in any convenient manner. An endless feed-apron conducts the canes to the machine, as in ordinary roller-mills.