106 PROCESS OF MANUFACTURE. 
at this stage it is perfectly clear, and of the finest color 
and flavor. 
The only attention specially required during this part of 
the operation is to properly regulate the flow of syrup into 
the filter E by means of the adjustable gate. It should 
not be allowed to pass so rapidly as to drain too much the 
pan B, in which the depth of juice should be at least twice 
as great as in any other, or before the proper degree of 
density has been reached. Nor should it be unduly re- 
tarded. In either case the filtration will be imperfect. 
The filter should be refilled with fresh or revivified bone- 
black before the beginning of each day’s work. If reburnt 
bone-black is used, the dust should first be sifted out. 
Take a piece of thin flannel or canvas of an open texture, 
wet it, and spread it smoothly upon the slatted bottom of 
the filtering-box. Then fill in the bone-black gradually, 
packing it down tightly so as to leave no crevices. When 
it is filled to the proper level, draw a little of the coal from 
the central parts toward the sides so as to leave the surface 
slightly elevated at the sides. Cover with a cloth of the 
same kind as that which lines the bottom, and confine it 
closely at the edges by means of the wooden frame. Fill 
the empty space above the cloth with hot water, taking 
care not to disturb the surface of the bone-black. The 
stream of water, in pouring it, shonld be received upon a 
piece of board or tin plate resting on the cloth. Another 
mode of filling the filter is to fasten down the cloth on the 
bottom of the box, close the outlet, and pour in hot water 
until it is about half full. Then add the bone-black. When 
this mode is adopted, the bottom cloth must be confined 
very securely at the sides, or the small fragments of the 
- charcoal will find their way under it into the chamber 
below. 
It is convenient to have a movable stand of the height 
