96 ANNUAL OF SCIENTIFIC DISCOVERY, 



its surface. The more completely these impurities are removed, the 

 greater will be the brightness and value of the finished product. In 

 the new process the juice passes through a wire strainer direct from 

 the spout of the mill into the clarifiers, where it is raised to boiling 

 heat by the application of steam, at which temperature it is kept for 

 about three minutes, by which time the whole of its albuminous con- 

 stituents and feculent matters will have been coagulated and chemi- 

 cally separated, but will, of course, still remain mechanically mixed, 

 and, in the form of light fleck, pervade the entire bulk of the fluid. 

 These substances are then effectually removed by a process similar to 

 that employed in the manufacture of paper. A drum of about two 

 feet in diameter and from four to five feet in length is made to revolve 

 slowly in a small semi-circular tray or vessel. This drum is covered 

 with fine wire cloth, through which the water forces its way, leaving a 

 muddy coating of extraneous matters on the other side, which coming 

 in contact as it revolves with a fixed scraper, similar in principle to 

 the " doctor" employed in calico printing, is made to fall off in a state 

 something like dry mud into a receptacle prepared for it. The pro- 

 cess is self-acting. It takes in its own supply of foul liquor from an 

 elevated cistern, delivers the clear juice into the evaporating pan, and 

 discharges the refuse as we have already stated. 



Up to this stage the advantages obtained must be evident to all who 

 are acquainted with this interesting branch of manufacture. The 

 liquor being received direct from the press, avoids the necessity of the 

 use of liquor pumps ; the clarifiers, not being used as subsiding vessels, 

 are not required to be so large ; the loss of juice in the removal of 

 the scum and in the sediment is prevented ; the use of the " mont- 

 jus" is rendered unnecessary ; the coagulation of the albuminous 

 matter is more rapidly obtained ; the evaporating process may follow 

 immediately after the pressing of the canes ; and finally, the self- 

 cleansing filter performs its work much better than any continuous 

 process of skimming, and renders unnecessary that watchful attend- 

 ance which is now so imperatively necessary in order to obtain the 

 required brightness and color of the sugar. The saving of manual 

 labor by these improvements is self-evident. 



On the various modes of boiling and concentrating the juice at 

 present in use, whether by a series of semi-globular pans, the vacuum 

 pan, Gadsden's pan, or the apparatus of Mr. Crossly or Mr. Schroder, 

 it is not necessary now to speak, the principle involved in one and all 

 of them being the same --that of evaporating the fluid from the sac- 

 charine matter. The inventor of the process now under consideration, 

 contends that, in all the existing arrangements for the separation of 

 the water from the sugar, boiling under any form, or the use of 

 surfaces or pipes heated by steam, must be totally excluded, if the 

 formation of molasses is to be prevented. It is a well established fact 

 that a thermometer placed in a solution heated by steam or the direct 

 action of fire furnishes no indication of the temperature to which the 

 liquid is exposed, as a vast amount of latent heat is absorbed by fluids 

 in their formation into steam. To the forge tfulness of this simple fact 



