On the Manufachire of Muscovado Sugar, 3 1 7 



much until the liquor is rich and viscid with sugar; that 

 every filtration abates as the interstices of the cloth become 

 narrowed, or clogged with filth ; and that a rich saccharine 

 liquor expanded on a large cloth in a basket, in the usual 

 mode of filtration, will soon be chilled, and incapable of 

 passing through the chilled and agglutinated filth ; it will 

 readily appear that the quantity of sweets retained in and 

 upon the cloth would cause an enormous defalcation of the 

 sugar, and great labour in washing out the sweets for the 

 stillhouse, and the filth from any great filter, We are to 

 revert, then, to the small filter above mentioned, acting by 

 the pressure of a high column of liquor, in order to obviate 

 the described inconveniences. 



It may appear paradoxical at the first view, but it is a fact 

 demonstrated in every schoolrbook of natural philosophy, 

 that the pressure of the liquor on the filter is the same whe- 

 ther the superincumbent column consists of a ton or ot a 

 pint of the liquor, provided the heiglits of these columns be 

 equal. 



Therefore, instead of making an instrument to give a ton 

 of pressure, by containing about a ton, or 250 gallons of 

 liquor, I have given an equivalent pressure by a pint or two 

 contained in a slender perpendicular tube : and instead of 

 setting the filtrating bag to a great capacity, I have set it 

 vertical, flat, and with the opposite parallel sides so near to , 

 each other, as to leave room only for the filth to be collected 

 from half a ton or a ton of sugar. 



By such mechanism and pressure the juice may be fil- 

 trated truly and expeditiously, even when it is so rich and 

 viscid wiln sugar that it could not pass through any filtrat- 

 ing mediumi used in the ordinary way. The filtration keeps 

 pace with the ladling forward, when the cloth measures 

 ^bout 10 or 12 feet square, and the flattened bag about 

 5 square feet: and the same bag will clean from 10 to 15 

 or 20 hundred weight of sugar, according to the nature of 

 the juice and the care of the workman in the previous de- 

 purations by yawing and skimming. 



By these means, also, the whole quantity of liquor m the 

 filter at any time niay fall short of a gallon ; and the quan- 

 tity 



