Middlebury register. (Middlebury, Vt.) 1886-1937, 1896-11-06
HOW SALT is MINED.
METHODS EMPLOYED AT THE EXTEN.
SIVE WORKS IN MICHIGAN.


1850 at which Time 1t Really Began.
The existence of salt springs in the
lower peninsula of Michigan was known
to the Indians long prior to the advent |
of the white men in the country, and |
they were rcsorted to by both Indians
and wild animals. So well known was /
this fact of the presence of salt springs |
that the general government made nu
merous reservations of lands which were
supposed to contain salt deposits. By |
the act Of admission of Michigan into !
the Union the state was authorized to
select ~ sections of salt land, or land
where the presence of saline springs in
dictated the occurrence of salt deposits |
On the organization of the geological
survey the state geolOgist, DR.. Douglas
HOughton made All examination, with
the view to the selection of these lands. |
and i'll 1888 reported the results of his
observations. Still these examinations
were limited to surface indications, and
no extended experiments were made to
probe the coast far below the surface
However, bOrings were finally under
taken in several localities, resulting
generally in such a good measure of sue
cess as to stimulate still further trials,
developing such gratifying results, es-
pecially in the Saginaw valley, that in
1859 the first company was organized
for the manufacture of salt, since which
period this industry has reached its
present stupendous proportions adding
greatly TO the wealth and reputation Of
the state and especially to the growth
of the cities and the region in which
the business is carried on.
The origin of these deposits is not
known. Whence the waters, lying SO
far beneath the surface, derive their sa
line property there is no apparent means
of determining, nor is the boundary Of
the surface known beneath which these
deposits of brine may be found. The
Michigan salt group has wide extent
in the state, though thus far the great
est successes have come from the Sagi-
nav valley. Where the lowest horizon
is found i'll the salt group the brine is
found to be the strongest, greatest in
amount and best in quality. 1t is for
this reason that salt wells in the Sagi
nav valley have proved to be more val
liable than elsewhere. 1t is the region
i'll which the greatest depression occurs.
The salt group here lies at a depth
reaching to more than 1000 feet below
4 the surface of the lake. At what depth
below the surface of the lake this brine
is found the writer is unable to state.
Of one thing there is an apparent GER
tainty, that the supply of the brine is
inexhaustible. The extent to which the
manufacture of salt in Michigan may
be carried on is one Of cost and demand
The brine may be assumed as existing
in quantity far i'll excess Of our ability
to diminish it.
OF the two modes of securing the
evaporation of the water, either by the
application Of solar or artificial heat,
the latter is the method mainly resort
ed to in the Saginaw valley. Solar evap-
Grafton is effected by exposing the brine
in shallow wooden watts. Such watts as
are used are about Is feet square and
inches deep. They are supported on
posts above the ground and are provided
with roof, which is readily moved or
the watts or off from them to cover the
brine from the rain or to expose it to
the sun, as required. The process is be-
gun in March and the contents removed
in July, the product of the second fill
ing is taken out the 1st of Septemb Der,
and the third and final removal occurs
the last of October. The annual product
Of a single salt vat of this size is so
bushels.
A kettle block contains 90 or 60 ket-
ties set close together and in rows III
closed in stonework or brickwork. A
launder connects with cistern kept
filled with brine and runs along be-
tween the rows of kettles, and from this
launder the brine is drawn out into the
kettles by opening lateral spout.
When 70 per cent of the water has been
boiled away, the salt is dipped out into
a basket or sieve to allow the water tC
run out Of it, after which it is emptied
into bin, where, after a sufficient time
about two weeks-it is ready to be
put into barrels. But the greatest ad
vance in the way of cheapening the cost
of the salt production has been achieved
by the use of steam to afford heat fol-
evaporation For tins purpose the eX
haust steam of the great mills in the
Saginaw region is used
Pans are also made use of. A so call
ed pan block, consisting of settler
pan, and packing room are inclosed in the
same building, The brine is drawn
| from the settler into the pan, to the bot
tom of which the fire is directly ap
piled, making the evaporation very rap
id and causing the salt to form continu
Ously.
The salt business in Michigan has
, swollen from the manufacture in 1850
J Of 1000 barrels to 3, 967, 286 in 1895.
The estimated capacity of the liz
3 firms now engaged in the manufacture
of salt in this state is ., $50, 900 barrels
per year. Detroit Free Press.