We resume our travels, following a car of sides from the beamhouse to
the sole leather tanyard. There are about 40 operations in the tanning
of sole leather, requiring about 100 days to produce first quality
leather. In the tanyard, we see more than 500 vats, each holding 300
sides, weighing about 23 pounds apiece. Each vat contains about 3000
gallons of liquor at an approximate cost of $100 a vat. Here we see
the sides slipped over sticks and placed in vats six feet deep, where
they receive the tanning, the real tanning process which preserves the
fibers giving the leather its life and long wearing qualities.
From the tanyard we go to the big wringers where the liquor is wrung
out, the hides are milled, dried and loaded on cars for the drying
loft, where they are allowed to dry or season preparatory to rolling.
This long building is sectioned off every 50 feet into chambers, where
the hides are hung in the same manner as in the vats. The temperature
of each room is changed from the outside temperature to a heat of 115
degrees, at which temperature the hides are dried and are ready for
rolling.]
[Illustration: In the rolling room, we see an operation requiring skill
and quickness of eye. The rollers pass to and fro over the side, which
is now hard and stiff, with a pressure of 300 tons. This rolling or
finishing gives it a high polish and we see a beautiful side of sole
leather, weighing from 18 to 25 pounds.]
[Illustration: HOW UPPER SHOE LEATHER IS TANNED
In the upper leather tannery we see the various operations preparatory
to the actual operation of tanning the hide, about the same as in
the sole leather tannery, with this difference: Upper leather in
this tannery is generally chrome tanned, a process requiring 30 days
and instead of vats sunken in the ground we see huge rolling drums
revolving at a rapid rate. This process is the most up-to-date method
and absolutely insures the wearing qualities of the leather. This
leather is very tough, yet is just as soft and pliable as glove leather
and as comfortable to the feet. It does not harden with age, nor does
it stiffen after being wet.]
[Illustration: UNHAIRING MACHINE
One of the most interesting sight while going through the tanneries is
the process of disposing of waste materials, such as hair, fleshings
and the sediments from the lime and sulphur vats.
The hair is separated into white, brown and black colors, each color
taking its turn through the huge mill or gin where the hair is dried
and afterwards baled. The brown and black are sold to plasterers. Those
who purchase the white often mix it with wool and use it for making
many useful articles.