, 1874-08-05
CORRESPONDENCE OF THE "SU-
GAR CANE"


ed, in your excellent periodical, articles
on sugar machinery, of more or less inter
est. I have lately also come across a pam
phlet which treats of special machinery
erected at Aba ell Wakf, in Egypt, with
discussions on the same. The reading OF
the various papers, referred to, have led
me to. compare my W experience IN the
matter, embracing a period OF fourteen
years. constant practical connection, as
engineer, with a number of sugar es-
tates.
The diversity Of opinion on sugar ma
chinery, held by gentlemen of u%ndoubted
mechanical and scientific knowledge, can
only be accounted for by supposing that
the want of time and opportunity, to make
the necessary experiments, has prevented
the majority arriving at correct conclu-
sions, as to the best proportions for a good
mill. Several examples. showing the SUI
perfcial way in which this matter is treat
e1, may be found in the pamphlet here
referred to, such as asserting that the rolls
Of the Aba ell Wakf mills, at speeds vary
ing from is to SO feet per minute, gave
equally good results. Had the author OF
this assertion made direct experiments, on
the extraction of these mills, he would
have found a considerable loss OF juice,
at the higher speeds. Also, if the gentle
man who states the average extraction OF
cane Juice in the West Indies to be, from
rs to so per cent. of the weight OF the
canes, would give the question closer at
t%ention, he would find himself 6 eatly IN
error. The average extraction In the
West Indies does not reach IS per cent,
and the average extraction OF the largest,
and most caretully-fed mills, is about 70
per cent. They are equally in error, those
gentlemen who recommend rolls OF small
diameter, great length, and high speeds.
Without entering further into the matter
at present, l would particularly call atten-
ton to the mill lately erected Oh the es-
tate "Mercedita," property Of DR.. Juan
Serralles. This mill, with interior canes,
and low motive power, gives the highest
extraction of any mill of which [ have au-
thentic record. The good results obtain
ed from this mill are entirely due to the
large diameter, and slow speed of the rolls.
The speed, l believe, to be the slOwest of
any steam mill yet erected. The average
cAGIdcClOus as sHoWH NY d Sl0dI nuAl1oCt "a
direct experiments Chat is, by weighing
the canes and the megass obtained from
them), is IS per cent. Indirect expert
ments (that is, taking a quantity of megass,
weighing it, having it thoroughly washed
and dried, then calculating the extraction
by DR.. Icery's formula), of which a great
number have been made, %corroborate the
above results. An armful of megass. taken
from the whole breadth of the megass ele-
vator, weighed when fresh IS lbs. after
being washed and dried it weighed 8 lbs.,
which is equal to "a per cent. 4 lbs. OF
freshmegass give, when washed and dried,
ga ounces, which is equal to 1855 per cent,
the woody matter in the cane, in both
cases, being 13 per cent. The method /
adopts as follows THE megass is taken
as it leaves the mill, and the weight noted
it is then stepped inhot water for some time,
we'll rubbed, washed, and wrung out it is
then put in the sun to- dry for three OF
four days, until two successive weighings,
With ap interval Of twelve hours, show no
loss which proves it to have parted with
Al MOISTURE. During The onerati0n q small