The Slate (Bourbon) Iron Furnace is rich in history. You may
want to read more about it on the internet if you have time.
Thanks to Owingsville Parks and Recreation for permission to
establish this Earthcache!
HISTORY: In October, 1782, Jacob Myers came from
Baltimore, Maryland, to this region, and soon afterwards patented
5,434 acres of land on Slate creek. In March, 1791, he commenced
the erection of a furnace. A few months later he sold most of his
interest in the furnace to a group of men including John Cockey
Owings for whom nearby Owingsville was named. The first blast made
by the furnace was in 1792. What is now Bath County was then
Bourbon County, and the furnace was so named.
Bourbon furnace supplied the early settlers of Kentucky with all
the castings they needed, such as heating stoves, cooking utensils,
flat-irons, etc. After Slate forge was built the blacksmiths of the
State were supplied by it with bar iron. The castings and bar iron
were hauled in wagons to all parts of the State, and distributed
through the principal stores in the towns. Products of the furnace
and the forge were also hauled to Licking river, a distance of
seven miles, and put into flat-boats and floated to Cincinnati and
Louisville on the Ohio. In 1810 Colonel Thomas Deye Owings (son of
John Owings) had a contract with the United States Government to
furnish cannon balls, grape shot, etc., to the navy. He also
furnished General Jackson with cannon balls, grape shot, chain
shot, etc., to use against the British, and they were so used at
the battle of New Orleans on the 8th of January, 1815.
Modern Day Photo of Slate Furnace
Photo by Miller, 1919
IRON ORE:The two best grades of iron ores are hematite
and magnetite. Hematite molecules contain two atoms of iron,
combined with three atoms of oxygen. They are red in color and
contain up to 70% iron. Hematite, also called red ocher, was used
as a red pigment in cave men drawings. Magnetite molecules contain
three atoms of iron and four atoms of oxygen. They are black in
color, magnetic, and contain up to 72% iron. Magnetite, also called
lodestone or leadstone, was suspended on a string and used as a
compass by the ancient Chinese.
Bourbon furnace used the Clinton ore from two banks two miles
south of the furnace—one called the Howard hill bank and the
other called the Block-house bank. Clinton iron ore seams follow
the western foothills of the Appalachian Mountain chain and are one
to four feet thick. In the Appalachian areas of Northern states,
especially New York and Pennsylvania, this ore appears mainly as
magnetite. From there down to the end of the Appalachians in
Alabama, hematite predominates. In the Kentucky foothills, the
Clinton formation was commonly reached by removal of a two to
30-foot soil overlay by strip mining techniques, using scrapers and
plows pulled by oxen.
THE PROCESS: When operating, these furnaces were charged
by adding, in turn, layers of charcoal, limestone, and iron ore,
which were dumped in from the top of the furnace. These additions
were repeated several times, until the top of the furnace was
reached. The furnace was then ignited at the bottom, and a strong
blast of air was admitted to fan the flames. The air was supplied
under pressure, by a bellows connected to a water mill, which was
turned by water flowing from a dam. The heat melted both the iron
and the limestone. The iron, being heavier, settled to the bottom
of the furnace, where it was drained into sand molds. The shape of
the sand molds was such as to remind the ironmakers of a sow and
suckling pigs. Thus, the cast iron was called "pig iron." The
molten limestone acted as an absorbent for impurities in the iron,
and being lighter than iron, floated on top, where it was drained
away separately as slag. Once started, the furnace was run day and
night, seven days a week, with new charges being continuously added
at the top of the furnace.
THE DEMISE:Massive layers of hematite, located around
Lake Superior, and easily dug, because of light soil overlay, led
to the demise of the old Kentucky iron furnaces in the 19th
century. At the Great Lakes, the hardwood supply problem was solved
by use of Appalachian coal (converted into coke) as a replacement
for charcoal. The final blast at the Slate (Bourbon) furnace was in
1838.
To get credit for this Earthcache, please answer the following
questions via email:
- What type of iron ore was mined locally to be processed in this
furnace?
- Approximately how tall is the furnace?
- What purpose did limestone serve in the ironmaking
process?