Notwithstanding the process we have just described has been succesafully and advantageously carried into effect, with British machinery, in the Wand of Ceylon, it does not appear, from the eminent success which has attended the rice-preparing establishment of Messrs. Lucas and Ewbank at R,otherhithe, near London, where a different process is employed, that the former is the best pmible or the only good plan of proceeding. The gentlemen we have named have had several patents for improvements in rice-cleaning machinery; and the excellence of their products has been the cause of the establishment of rival concern; all of which receive the rough rice, or paddy, from abroad at a con siderable less import duty than the clean rice, and, by preparing it for sale, derive, or have derived, considerable profits thereby.
The cleansing of rice in this country is quite of modern introduction, and, from its apparently growing importance, we shall here add some account of the processes recently patented for that purpose.
Mr. Ewbank's patent of 1819 informs us that the rough ice, or paddy, is first cleansed from dirt and other foreign matter, by passing it over a screen, which, detaining the rice, allow the impurities to pass through. The paddy in this state is taken to millstones, set at a proper distance apart to rub off the external shells or husks; the husks are next blown away by a fanning machine ; the rice, thus partially cleaned, is then deposited in mortars, where it is beaten and triturated for depriving it of the thin under pellicles, or red skin ; and when the trituration has been carried far enough, the contents of the mortars are sifted upon a " sloping and revolving screen," which is composed of three distinct wire-cloths, of different degrees of fineness. The finest under cloth allows the dust or flour to pass through, but detains the broken rice ; the second or middle cloth separates the broken, and detains the whole rice, while the coarsest upper cloth allows only the whole rice or husked grain to pass through, and detains the unhusked, which is taken back to the millstones to be operated upon again. The rice, still but imperfectly clean, is afterwards taken to the polishing and whitening machine, which consists of two cylinders placed concentrically ; the exterior cylinder is fixed or stationary, and the interior one, which is made to revolve, is covered with sheep-skins with the wool on, and stretched upon boards, or other framing with the wool on the outside. Between
these two cylinders the rice is put, and the inner cylinder being made to revolve (by the action of a steam engine or other prime mover), the rice is brushed by the constant friction of the wool, and•thereby polished and whitened ; in other words, brought to a state fitted for the market.
The foregoing comprises the substance of the processes described in Mr. Ewbank's specification of the patent of 1819. The second patent, granted jointly to Messrs. Lucas and Ewbank, in May, 1827, relates to certain improve ments upon the former, and is confined to a superior method of treating the rice after it has been deprived of the external shell or husk by the operation already described, or by any other mode. This improvement is founded upon the observation that the thin under pellicle, of a reddish colour, which remains upon the grain after it has been shelled, is of a glutinous or gummy nature, and that the beating or triturating of it in the mortars, occasioned the mass to become very sticky and difficult to operate upon towards the close of the pro cess ; and that that portion of the rice which had already been stripped of its red pellicle, became injured in its colour by continuing theuntil the remainder in the mass had also been deprived of their red To avoid this inconvenience, Messrs. Lucas and Ewbank now use successively two or more sets of mortars, for conducting the last operation, in this manner : when the gummy or glutinous matter begins to disengage itself (which is immediately manifested 'by the rice moving sluggishly under the pestles), it is to be taken out of the first set of mortars, and carried to a second set, wherein is to be mixed with the rice, a quantity of the external husks well dried, in the propor tion of one-fourth or two-fifths in bulk to that of the rice. The triturating and beating process is then renewed upon this mixture, the dry husks greatly assisting in cleaning and whitening the grain. After this the mass is to be fanned and screened, to separate the refine ; when the rice is taken to the polishing machine, as before described, which terminates the process. The fanning and screening it to be done as often as may be found necessary, between each triturating pro cess, which may extend to three or four distinct operations, according to the quality or state of the rice.