g from the
one side to the other are laid on the top of the furnace walls, and are
covered with wooden boards, forming a temporary floor. Two or three feet
above this floor a strong horizontal network of poles of wood sustains a
number of straw ropes, with iron hooks hanging down, and of such a
length that the hooks nearly touch the wooden floor. The floor is
thereupon covered with a mixture of clay and small stones, 4 to 5 inches
thick, the workman being careful to incrustate the iron hooks into this
material. It is allowed to dry gradually, and when considered
sufficiently hardened, the wooden beams and flooring are removed with
the necessary precautions. The bottom of the pan remains suspended by
means of the ropes. The open spaces left all round between the bottom
and the top of the furnace walls are then filled up, and the border of
the pan, 9 inches to 10 inches high, is made of a similar mixture. It is
said that this extraordinary construction lasts from 40 to 50 days when
well made, and that it can be filled 16 times in 24 hours, with an
average of 500 litres of concentrated lye at each filling; but the
quantity depends upon the weather, and is less in winter than in summer.
During the cold season one pan yields 140 litres (of salt) each time it
is filled, and in the hot season from 190 to 210 litres. The average
consumpt of fuel is said to be 1500 kilos. in 24 hours.

In Persia, near Ballakhan, salt is still made, and has been made from
time immemorial, in a very primitive way, which is described by Bellen,
in his description of his journey in 1872 from the Indus to the Tigris,
as follows:--

"For several miles our road led over a succession of salt pits and
ovens, and lying about we found several samples of the alimentary salt
prepared here from the soil. It was in fine white granules massed
together in the form of the earthen vessel in which the salt had been
evaporated. The process of collecting the salt is very rough and simple.
A conical pit or basin, 7 or 8 feet deep and about 12 feet in diameter
is dug, and around it are excavated a succession of smaller pits, each
about 2 feet diameter by 11/2 feet deep. On one side of the large pit
is a deep excavation, to which the descent from the pit is by a sloping
bank. In this excavation is a domed oven with a couple of fireplaces. At
a little distance off are the piles of earth scraped from the surface
and ready for treatment. And, lastly, circling round each p