MANUFACTURE OF SUGAR IN BARBADOES. 
61 
significant quantity, which might find a ready market, or 
be advantageously used upon the estate in feeding stock, 
now so grievouslyly neglected, while the increased yield of 
sugar of superior quality, for which the demand at home 
might become almost indefinite, being only limited by the 
price, would amply remunerate the enterprising grower. 
The filtered liquor must now be concentrated to syrup, 
which may be done over the open fire, or by steam of mo- 
derate pressure circulating in a spiral of copper pipe laid 
at the bottom of the evaporating vessel, which should be 
large and shallow, and as unlike as possible the tea-cup 
shaped coppers now in use. Here it may be boiled down 
rapidly until the temperature of ebullition rises to 225 6 or 
thereabouts, without injury to the syrup. When cold, it 
will then have a density of 1.33, or near it, and mark the 
3Sth degree of Baume's hydrometer. Beyond this point it 
will not be safe to go. The concentration of the syrup to 
the crystallizing point must be completed either by the 
vacuum-pan — the most perfect of all means, or by one of 
the several substitutes for that invaluable invention, of 
which an account will be found in Dr. Evan's Manual 
and in other works on the subject. Among these, Gades- 
den's apparatus may be mentioned as having been used 
with some success on an estate near Bridgetown, the differ- 
ence in colour and grain of the sugar made by this machine 
and that made by the old process over the open fire, at the 
same time and from the same canes, being quite extraor- 
dinary. The chief difficulty attending the use of the 
vacuum-pan in Barbadoes will probably arise from defi- 
ciency of water for condensation; by sinking wells, how- 
ever, with the precaution required by the peculiar geologi- 
cal structure of the island, this may be overcome. 
Tiie old-fashioned flat shallow crystallizing vessels are 
exceedingly defective, inasmuch as they permit the too 
rapid cooling of the syrup, and thus hinder the formation 
of bold and distinct crystals essential to a good process. 
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