228 E V A P O R A T IN G H O U S E S . E V A P O R A T IO N BY CORDS . 229
ther attention, or manual labour, till it is
completed. When the water is nearly saturated,
it passes to a large building, where
are the pans for boiling, and the salt is
crystallized in the usual method. That
the reader may form an idea of the quantity
of water evaporated before it comes to
the pans, I will state the reduction at
each of the evaporating houses :
8000 hogsheads, when received at Nos. 1. and 2., contain
about IJ per cent, of salt ...................reduced to 4000
4000 hogsheads, when received at No 3., contain about
3 per cent, of salt .............................. reduced to 1000
1000 hogsheads, when received at No. 4., contain about
12 per cent, of salt ............................. reduced to 55,0
550 hogsheads, received at the pans, contain near 22
per cent, of salt.
Thus, out of every 8000 hogsheads, passing
through the Maisons d’Epines, 7450
are evaporated by the air in summer, and
about 7000 in winter; and only one-sixteenth
part of the fuel is consumed, that
would be required for evaporating the
whole quantity of water by fire.
The faggots are changed at periods of
from four to seven years. Those in Nos.
1. and 2., where the saline impregnation is
weak, will decay sooner than in Nos. 3.
and 4. In No. 3. all the twigs acquire so
thick a coating of selenite, that when broken
off, they resemble stems and branches of
encrinites.
The Maison de Cordes was invented by
an ingenious Savoyard, named Buttel. It
is forty yards in length and eleven wide: it
is much stronger than the Maison d’Epines,
the roof being supported by six arches of
stone work; the intermediate spaces on
the sides being left open. In every one of
these divisions are twelve hundred cords,
in rows of twenty-four each, suspended
from the roof, and fixed tight at bottom.
The cords are about sixteen feet in length.
The water is raised to a reservoir at the
top of the building, and distributed into a
number of small transverse canals, each
row of twenty-four cords having one of
these canals over it, which is so pierced as
to admit the water to trickle down each
separate cord, drop by drop. The original
intention of this building was to crystallize
the salt itself upon the cords, for which
purpose the water was made use of from
the pans after it had deposited a quantity
of salt in the first boiling, to serve the expense
of fuel in a second boiling; the re-
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