, 1872-11-09

OhjSAlIAb va
liberal application. A member of the
Committee on a former visit was shewn a
held OF 9th Rattoons which by its use was
yielding 2 H~ogsheads per acre.
PROCESS OF MANUFACTURE IN
DEMERARA.
The Committee during their enforced
stay here employed their time in inspecting
the principal Sugar Works in the vicinity
OF George Town. The process employed
IN all these works is the following.
The canes are brought to the main line
OF Iramway by the planter. The factory
takes them to the mill where the wagon is
tilted up by a similar method to that en-
ployed IN the French Usines. The megass
Is elevated and is put by boxes running
upon an elevated Railway into " Logies "
or the yard to dry. The juice flows from
the mill through the Straiuers into a pump
getting treated with Bi-Sulphite Of lime in
transltu The pump ~elevates it to the clari7
hers where /. is cracked, racked and, treated
with lime. From this it flows on to the
Copper Wall where it is cleaned thorough
~, and is raised by Montejus into subsiders
where 1T is allowed to rest 8 or 10 hours.
From these Vessels the Vacuum pan
draws the juice and boils it to Sugar. The
hrSt quality being crystaliized, and cured
as soon as possible. The molasses, when
good, is worked into syrup of the following
day until they get so thick that they darken
the first quality. They are then boiled by
themselves, and form the second quality
sugar being allowed several days to granu-
late IN the coolers. The skimmings from
CHARTERS, and copper wall and the subsid-
in8s from syrup boxes and the molasses
from second quality sugar going to make
rum.
1t will be seen that the essential differ
ence between this and the French process
is the entire elimination of the charcoal
filters and Triple Ef9t and with them the
necessity of a large supply of pure water a
matter OF much Importance where this can
not easily be procured. This process is
certainly simpler and less expensive, but
whether 1t extracts the same amount of SUI
gar from the juice may be doubted. We
were unable to procure any positive data
on this point, The charcoal filter sepa-
rates from the juice not. only the focal
matter but also The soluble salts contained
in it.
The presence of these principally salts
ofsoda and potash) is known to have the
effect of preventing a certain amount of SUI
gar from crystallising. Experiments were
instituted this year to decide this point in
two of the principal Factories of Martini
que during the last fortnight of their work.
ing but the results have not yet been pub
lished.
In conclusion we cannot too strongly re-
commend the establishment 10 this Island
OF a Central Factory calculated to make
fron 1900 to 5000 Tons of sugar annually.
The absence of an indispensable supply of
fresh or soft water, not to speak Of their
cost, renders, in our opinion, the French
Uslne system impracticable here. We
must discard filtration by charcoal, and the
Triple Ef6t. But it appears to. US that
the Demerara system would be admirably
adapted TO our requirements while the cost
is comparatively moderate, 1t must be re-
membered, too, that the quality of Sugar
made in Demerara is better suited to our
markets and commands higher prices than
the French Usine sugar. In other words
the process of manufacture We recommend
would retain alone the multitubular Boz
lers, CHARTERS, Subsiders, Vacuum Pans
and Centrifugals. We have seen an esti-
-