This large round gear-toothed stone on the lawn of
the Clay County Archives building in Liberty, Missouri is:
a)
an old mill stone used
to make flour
b)
an old mill stone used
to tan leather
c)
an instrument of
torture for people who don’t rewind their microfilms.
If you selected (b), you’re
correct! Here are some interesting
facts about the stone:
It was carved from a
single piece of limestone.
It measures 8” thick
and 65” in diameter and is estimated to weigh 1,000 pounds.
It has a square 7” hole
in the center to accommodate an axle.
Its official name is an
“edge runner stone”.
It was recently found
five miles northwest of Liberty, where land is currently being developed for
new housing.
In the early days of our
country, the dried, crushed bark from oak trees was used in the leather tanning
process. A tanyard usually employed its
own mill to grind tan bark. Tannin, an
acidic substance, was obtained from the bark of oak trees. A spud, or peeling iron, was used to peel
bark from the trees. This was usually
done in the spring when peeling was easy and the bark contained the maximum
amount of tannin. The bark was cut into
long strips and allowed to air dry on racks.
The dried bark was then coarsely ground in a tan bark mill.
The mill consisted of a
deeply corrugated edge runner stone (like ours) that rolled on a wooden
bed. The mill was usually powered by a
horse or an ox. The bark was then
thrown into a shallow leaching pit, where cold water was poured on it to yield
a thick, sickly-sweet tannin liquor.
Scraped hides were then laid into the pit to absorb the tannin. This process transformed certain proteins in
the animal tissue into compounds that resisted decay.
Oak bark tanning is rarely
practiced today, the industry having converted to a much quicker chrome tanning
process. However, oak-tanned leather is
still considered the highest quality.
Prior to 1830, John P.C.
Dunn bought 60 acres of land from William Davis five miles northwest of
Liberty. He operated a tanyard in
partnership with John and Reuben Long.
From 1841 to 1848, Joseph Henry Jenkins, in partnership with Charles
Mann, operated Dunn and Long’s old tanyard for $50 a year rent on the property
and the mill.
The following ad was placed
in the Western Star, a Liberty newspaper, on April 9, 1841:
TANNING on the SHARES
The undersigned having
commenced the tanning business At Dun’s old tanyard, five miles North West of
Liberty, Respectfully inform the people of Clay county, that they are now
prepared to receive hides to tan on the shares. Particular attention will be paid to all hides entrusted to their
care.
JENKINS
& MANN
March 1st, 1841
From 1848 to 1852, the old
Dunn property was rented at various times to O.W. Rudd, William Thomason and
Mrs. Simmons, none of whom operated the tanyard. By 1852 the tanyard is described as “having gone to decay”.
This close up view of the stone shows the square hole for the axle. Also notice the four notches near the outside edge of the stone.
This view is from the back to show the iron bracing buried deep in a pad of concrete.
