Evening journal., 1896-11-03
HOW SALT is MINED.
METHODS EMPLOYED AT THE ExTEN-
slvE WORl<S ~ MICHIGAN.

The Supply of Raw Material, which is
Brine, is Practically Inexhaustible-Th I
Industry Has croun Enormously Since
1880. Mt which limo 1t Really Began.
The existence Of salt springs in the
lower peninsula Of Michigan was known
20 the Indians long prior to the advent
Of the white men in the country, and |
thoy were resortcd 70 by both Indians
rd Wild animals. So well known was
thia fact of the presence of salt springs
that the general government made nu-
a.erous reservations Of lands which were
supposed to contain salt deposits. BY
thc act Of admission Of Michigan into
tho Union the state was authorized to
select ~ sections OF salt land, or land
whore the presence Of saline springs in
dicatod the occurrence of salt deposits.
On the organization Of tho geological
SURVEY the state geoloeist, Dr. Douglas
Houghton, made an examination, with
the view to the selection Of these lands,
and in 1888 reported the results of his
observations Still these examinations
were limited TO surface indications. and
no extended experiments were made 20
probe the coast far below the surface.
However, borings wero finally under
takon 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
tho 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 in 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-
naw valley have proved to be more val
uable than elsewhere. 1t is the region
in which the greatest depression occurs
The salt group here lies at a depth
reaching to more than 1,O00 feet below
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 ono thing there is an apparent cer-
tainty, that the supply Of tho brine is
inexhaustible The extent 20 which the
manufacture Of salt in Michigan may
be carried On is one of cost and demand
Tho brine may be assumed as existing
in quantity far in excess Of our ability
to diminish it.
OF tho two modes Of securing TIN
evaporation Of tho water, either by th'
application Of solar or artificial heat
the latter IS the method mainly resort
Cd 70 in the Saginaw valley. Solar ovap
oraticn is effected by exposing the brine
in shallow wooden vats Such watts a'
are used are about 18 feet square and {
inches deep. They arc supported on
posts above the ground and are provided
with a roof, which is readily moved on
the watts CT OFF from them TO cover tho
brine from the rain or TO expose it tC
the sun, as required. The process is be
gun in March and the contentsremoveC
in July, tho product Of the second fill
ing is taken out tho 1st of September
Il
the last Of October The annual produc
Of single salt vat of this size is 90
, bushels.
A kettle block contains 90 or 60 kct
ties, set close together and in rows in
closed in atonework or briskwork.
launder connects with q cisteln KEEP
filled with brine and runs along be
tween the rows of kettles, and from thi
launder the brine is drawn out into tn
kettles by opening a lateral spout
When 40 per cent OF the water has beel
! boiled away, the salt is dipped out int
: q basket or sieve TO allow the water t
3 run out of it, after which it is omptie
! into O bin, where, after q sufficient tim
about two weeks--it is ready to b
put into barrels. Bus the greatest aJ
vance in tho way Of choGpeniug the COZ
Of tho salt production hes been achieve
Z by the use Of steam to afford heat &c
a evaporation. For this purpose the "a
4 haust steam of the great MILLS in I'll
! Saginaw region is used.
Pans arc also made use Of A so cal
Q ed pan block, consisting Of a Settler
! pan, and packing room arc inclosed in th
i same building The brine is draw
> from the settler into the pan, 20 the ho
% tom Of which tho fire is directly al
r piled, making the evaporation very raj
id and causing the salt 70 form continr
ously
The salt business in Michigan hi
& swollen from the manufacture in 1876
Of 1900 barrels to 1907, 266 il 1895.
n The estimated capacity Of rho II
b firms now engaged IN the manlfactm
" Of salt in this state is o, $50, 600 barre
it per year. Detroit FREQ Press.
D. Appreciated Scotch.