raised,
fresh water flowed down. The solvent power of the newly admitted water
was of course greater than that of water partially saturated, and
being also lighter it occupied the upper portion of the excavated
space. The combined effect was to give the cavity the form of an
inverted cone. The mode of extraction thus possessed the disadvantage
of removing the greatest quantity of the mineral where it was most
wanted for supporting the roof, and had given rise to occasional
accidents to the pipes underground. These were referred to in detail,
and the question was started as to possible legal complications
arising hereafter from new bore holes put down in close proximity to
the dividing line of different properties, the pumping of brine formed
under the conditions described presenting an altogether different
aspect from the pumping of water or natural brine.
The second part of the paper referred to the uses to which the brine
was applied, the chief one being the manufacture of common salt. For
this purpose the brine, as delivered from the wells, was run into a
large reservoir, where any earthy matter held in suspension was
allowed to settle. The clear solution was then run into pans sixty
feet long by twenty feet wide by two feet deep. Heat was applied at
one end by the combustion of small coal, beyond which longitudinal
walls, serving to support the pan and to distribute the heat,
conducted the products of combustion to the further extremity, where
they escaped into the chimney at a temperature of from 500 deg. to 700 deg.
Fahr. On the surface of the heated brine, kept at 196 deg. Fahr., minute
cubical crystals speedily formed. On the upper surface of these, other
small cubes of salt arranged themselves in such a way that, in course
of time, a hollow inverted pyramid of crystallized salt was formed.
This ultimately sank to the bottom, where other small crystals united
with it, so that the shape became frequently completely cubical. Every
second day the salt was "fished" out and laid on drainers to permit
the adhering brine to run back into the pans. For the production of
table salt the boiling was carried on much more rapidly, and at a
higher temperature than for salt intended for soda manufacture. The
crystals were very minute, and adhered together by the solidification
of the brine, effected by exposure on heated flues. For fishery
purposes the crystals were preferred very coarse in size. These were
obtained by evapo
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