a little
water remains, and evaporation will soon carry this away, leaving only
salt in the basin, waiting to be purified.

Not very many years ago one of the encyclopaedias remarked that "the
deposits of salt in the United States are unimportant." This was true
as far as the working of them was concerned, but in 1913 the United
States produced more than 34,000,000 barrels. Part of this was made by
evaporation of the waters of salt springs, and a small share from
Great Salt Lake in Utah. The early settlers in Utah used to gather
salt from the shallow bays or lagoons where the water evaporated
during the summer; but now dams of earth hold back the water in a
reservoir. In the spring the pumps are put to work and the reservoir
is soon filled with water. This is left to stand and give the
impurities a chance to settle to the bottom. Then it is allowed to
flow into smaller basins, while more water is pumped into the
reservoir. When autumn comes, the crop of salt is ready to be
harvested. It is in the form of a crust three to six inches thick,
some of it in large crystals, and some fine-grained. This crust is
broken by ploughs, and the salt is heaped up into great cones and left
for the rain to wash clean. Then it goes to the mill for purifying.
The water of Great Salt Lake is much more salty than that of the
ocean. It preserves timber remarkably well, and often salt from the
lake is put around telephone poles, seventy-five pounds being dropped
into the hole for each one. It has been suggested to soak timber in
the Lake, and then paint it with creosote to keep the wet out and the
salt in.

Salt is also made from the waters of salt springs, which the Indians
thought were the homes of evil spirits. At Salton, in California, an
area of more than one thousand acres, which lies two hundred and
sixty-four feet below sea level, is flooded with water from salt
springs. When this water has evaporated, all these acres are covered
with salt ten to twenty inches thick, and as dazzlingly white as if it
was snow. This great field is ploughed up with a massive four-wheeled
implement called a "salt-plough." It is run by steam and needs two men
to manage it. The heavy steel ploughshare breaks up the salt crust,
making broad, shallow furrows and throwing the salt in ridges on both
sides. The plough has hardly moved on before the crust begins to form
again. This broken crust is worked in water by men with hoes in order
to remove the bits o