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James Onuska
Dr. Boldurian
Archaeology Capstone
Draft 1 Submitted November 30, 2015
Thru the Field Farm (36WM0915)
Leather Assemblage: Description and Analysis
James W. Onuska
University of Pittsburgh at Greensburg
ABSTRACT
For three days in March 2008, emergency salvage excavations of a massive historic
midden feature were performed at the Thru the Field Farm site (36WM0915) to salvage any
artifacts during renovations of a home which occupies a historic house structure. Emergency
action was taken to discover, stabilize, and preserve anything of cultural significance. Amongst
the thousands of artifacts discovered within several layers of a trash midden was roughly 30
assorted leather artifacts of various kinds/types that have yet to be analyzed, categorized, and
identified. This research project’s main goal is to render credible identification of the “unknown”
objects in the miscellaneous leather assemblage so that nineteenth century life may be better
understood.
INTRODUCTION & BACKGROUND
The demolition of an 80 year old concrete porch in a Ligonier Township farm house in
March of 2008 took place that revealed thousands of artifacts. These artifacts were the contents
of a trash “midden” or discarded garbage heap from the owners of the house that were unwanted
for a hundred years or so. The midden was an unintentional time capsule filled with many
broken and decaying artifacts and ecofacts that had been covered up for over a century. The
artifacts and ecofacts had been well preserved under roughly 7 centimeters of concrete, 40
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centimeters of rubble, and 12 centimeters of massive clay deposits that helped in the
preservation. In the fourth stratum the buried refuse consisted of over 7,500 artifacts and
ecofacts including pottery shards, glassware, animal bones, peanut shells, shoes, newspapers,
toys, and a mummified mouse. Amongst all of these artifacts were 30 miscellaneous leather
artifacts. The property owner, Steven Patricia, believes the area near the home’s summer kitchen
and back door served as the dumping pile for the family. Since there was no organized method
of cleaning up garbage, broken items were merely tossed out of the window or door. The lead
archaeologist that rescued the artifacts Dr. Anthony Boldurian believes that the objects were
deposited from 1857 to 1927 three years prior to the porch being paved. Dr. Boldurian along
with his wife and son rescued these undisturbed artifacts before the farm house was renovated
and the dig would be re-covered. By analyzing these artifacts, Dr. Boldurian says we can “fill
out a bigger picture of the life and times of an everyday working farmstead in Ligonier Valley”
(Pickels 2009). What better way to study a person’s past lifestyles and existence than what they
threw away? It gives archaeologist a good representation of what was used and how they were
repaired and discarded when they were thought to be unusable.
LEATHER SOURCES
Animal skin is a fibrous living material that protects an organism from the environment.
It contains hair, sweat glands, fat and blood vessels as well as collagen fibers. These fibers are
made of coil-like molecules built of tiny fibrous strands that are intertwined and overlapping to
create a strong structure. Skins and hides of animals are a part of a class of natural materials
called skin products. Leather is one type of product that can be produced by particular tanning
processes. These products have made up many objects and materials that humans have used to
clothe, protect, build, and create basic fabric for many different uses (Richards 2000:2).
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Leather structure is made up of three dermal layers of skins including the epidermis,
corium (dermis), and the fleshy subcutaneous adipose. The epidermis is the outermost layer of
skin and contains all of hair, feathers, or scales that are normally removed before being worked
with. The dermis or corium is the layer of skin that contains the tiny coil-like molecules that are
intertwined and connected. It has two layers: the first layer containing grain membrane where
hair membrane and pores are located. The second layer contains collagen fibers which make up
the ground substance that connects the dermal structure. The dermis also consists of a ground
substance or fluid that surrounds the fibers along with fatty tissue. The thickness and strength of
the piece of leather is in the fiber network layer which is consists of the mesh of collagen fibrils
that are formed perpendicular to the surface layer. Fiber structure varies with different skin parts
and different species (Dempsey 1947: 21).
Different animals can all produce beautiful and unique types of leather. Most leathers are
made of mammal skins of animals such as cows, bison, horse, deer, sheep, goat, and pig. Each
animal has a different thickness, softness, durability, and pattern that leaves the tanner the option
to use a certain type for a particular object. Cow hide is normally used for shoe soles, belts, and
trunks because of the thickness and durability. Calf skin is used for more thin materials like
upholstery, shoe uppers, clothing, and book bindings because it is so soft and malleable. Bison
hide was used for Native American shields, boots, and other thick clothing. More exotic animal
leathers come from animals like reptiles, fish, and seal. These leather types have their explicit
uses but were mainly used for decoration or status. It really depends on what is available at the
time and what they artisan is trying to make (United Glove).
Animal skin can be tanned or untanned to produce a workable material. Most of the
cured animal hide artifacts fall into four categories: non-tanned, semi-tanned, native-tanned, and
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fully-tanned. Non-tanned leathers include rawhide, parchment, and vellum. Semi-tanned leather
are oil-tanned leathers that have just been soaked in either oil or a potash aluminum mineral
saline. Native-tanned leathers include leathers that have been tanned using a smoke technique or
brain-tanning method which will be explained later. Fully-tanned leathers are tanned using
vegetable tanning or mineral tanning methods. The objective of tanning is to remove all of the
soluble material, and render the skin impervious to rot and resistant to water. The type of
tanning method as well as the material used determines the leather’s resistance to moisture,
flexibility, appearance, and longevity.
TANNING PROCESS
Traditional tanning processes took many weeks and even months to produce quality
leathers. The tanning process begins after the animal skin has been removed from the carcass. It
is imperative to quickly store the hide after removing it from the animal so that rot does not set
in. If the hide is too far putrefied it becomes unusable. Refrigeration for later use or curing must
take place as soon as possible to stop the putrefaction. Curing is the process of salting the hide to
preserve and stop decomposition. By salting and air drying the hide, it becomes slightly dried
out to begin removal of moisture. After a week or so of curing the hide, rehydration begins by
soaking the cured hides in water to remove any dirt and soluble proteins. After rehydration,
removal of the hair and fleshy parts to expose the fibrous inner layer. To help remove the hair,
the hide can be placed into a hot moist room to partially rot the fatty tissue for easier removal.
When all of the fatty flesh parts and hair is removed one is left with collagen fibrous
materials that are ready to be tanned. Tanning is the process of treating the hide with tannin also
known as tannic acid. Tannin is an amorphous substance that can be found in plant roots, stems,
wood, bark, leaves, and fruit of many plants particularly in the bark of oak species and in sumac
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and myrobalan trees (Britannica 2015). By soaking hides in tannin the water is displaced and it
binds to the collagen fibers to make the leather waterproof and strong. There are many methods
of tanning that have different results that can be used for specific types of leather. The most
common tanning process is vegetable tanning. This was discovered by the Egyptians and
Hebrews around 400 BC. Extracts from plants were rich in tannin and could remove the water to
make the leather water resistant. The hide would be placed into the vegetable tannin mixture and
soaked in there for a couple of days so that the tannin can set into the collagen fibers. Another
common primitive method is oil or brain tanning. This process includes fatty oils and tissues or
brain tissue being spread across and pounded into dry hide. A more contemporary method for
tanning leathers is mineral tanning (How Stuff Works 2009). Mineral tanning produces a light
soft leather by soaking the hide in a saline bath of different metal salts. Chromium, aluminum,
and zirconium salts are common mineral salts that allow the process of tanning to be shortened to
days rather than weeks. After the tanning process was completed, the hides were washed and
hung over wooden rods in a warm, semi-moist shaded are so that they may properly dry. The
leather hides were then pulled back and forth across the rods to soften and evenly dry. After the
whole tanning process was done they pieces of leather could be shipped to different
manufacturing companies or plants to be produced into various items (How Stuff Works 2009).
During the 19th century, Pittsburgh was famous for is tanneries. North Allegheny was the
center point for leather production in Pittsburgh and booms from the 1880’s to the 1920’s.
Western Pennsylvania was one of the biggest leather produces in the country concentrated on
producing thick leather soles with tanneries spread throughout the mountain valleys. In 1900
there were roughly 254 working tanneries in Pennsylvania producing $55.6 million worth in
tanned leather compared to its closest competitor being New York with 147 tanneries producing
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$23 million in leather products. Along with tanning plants, many bark processing plants were
located near the tanning plants to produce the vegetable tannic acids. Small “tan yards” popped
up where bark could be processed into tannic acid next to the leather tanning vats. Along with
the processing of bark, the other raw material, hides and skins, was easily accessible to tanneries.
Pittsburgh had a thriving meat production district with slaughterhouses and butcheries that kept a
steady supply of hides and skins. Raw material plants processed both bark and hides and skins.
These plants mainly harvested hemlock and oak bark where the bark would be ground into a fine
powder and placed into a pit where the tannic acid would be leached out. The tanning process
would take roughly four to six months to complete. Once they were finished tanning they would
be taken to a finishing room where they would be treated with oils and coloring dyes and cut into
whatever shape needed. Leather from cattle was made into saddles, harnesses, shoes, and belts.
Sheepskin leather was made into pocketbooks and travel bags. Pig skins were high in demand
and were made into gloves and book covers. This was a process that gave a lot of jobs to
working Pittsburgh natives although people did not prefer to be live near these plants because of
the putrid smell the factories gave off. These factories produced a lot of goods for the local
population as well as shipped leather materials across the country as well as England and
Germany (Rotenstein 1997: 35) .
METHODS & PROCEDURE
Amongst the numerous artifacts recovered at the Thru the Fields Farm were 30
miscellaneous pieces that were cleaned and preserved. Dr. Boldurian kept the artifacts in a clean
temperature regulated room for a couple years until I chose to analyze, describe, and categorize
them. The assemblage was kept in a clean plastic box and was handled with powder free gloves
in the archaeology classroom. I took extensive notes that recorded the color, shape, size, length,
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width, thickness, and any other notable landmarks that each piece had. Each piece was different
and exhibited many different styles of leather as well as a couple of metal nails and a buckle
attached to the leather. I arranged the pieces in the box and labeled them 1-30. After all of the
pieces were arranged I took a picture of the entire assemblage and began to examine each piece
individually. Each piece was measured in centimeters for maximum length and width as well as
maximum thickness in millimeters and a picture was taken next to the ruler to show scale.
RESULTS
For the results portion I will share the dimensions as well as the descriptions of each
piece. Specimen 1 I described as a long leather strap section. It was rectangular in shape made
of dark very thick black leather. On both ends it was clean cut and showed sewing indentations.
Four separate sewing lines were observable with two separate sewing styles; two of each. The
“top” edge was clean cut but the “bottom” edge was jagged from one of the sewing lines.
Specimen 2 I described as a piece of a black shoe sole. The “bottom” of the sole was smooth but
the “top” was very rugged with evidence of matrix and deterioration of the leather. Along one of
the edges were nine distinct nail holes with six nails still puncturing the shoe sole. The nails
were oxidized and were barely still intact. Specimen 3 was a miscellaneous piece of leather. It
had a smooth tanned dermis surface and an unsmooth collagen “hairy” side. This piece of
leather was a natural brown color with a medium thickness but no distinguishable evidence of
any other significance. Specimen 4 was another miscellaneous piece of brown leather. This
piece also had a smooth dermal surface and a “hairy” collagen surface. On the left edge of the
leather piece it had very small intricate sewing holes. It was relatively thin but had clean cut
edges that shaped it into a kind of tapered rectangle. Specimen 5 was a thin dark black
miscellaneous leather piece with a smooth dermal surface. The other side of the piece was a
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little more rugged and course but still had evidence of a smooth dermal surface. All of the edges
were pretty clean cut and had intricate sewing holes along all of the edge margins.
Specimen 6 was a small dark brown leather shoe piece with a very distinct clean cut
pattern. One of the edges was a straight cut while the top part was a clean cut curved edge. It is
quite thin with a smooth dermal surface as well as a “hairy” collagen side. Intricate sewing holes
cover the curved edge as well as evidence of puncture marks in the center of the piece.
Specimen 7 was the same distinct pattern as specimen 6 however it was the mirrored opposite.
This piece also had a smooth dermal side but had more evidence of deterioration and cracking.
Specimen 7 also had evidence of puncture marks in the center of the piece very similar to
specimen 6 but the puncture marks did not match up perfectly. Specimen 8 was a very thin, dark
brown with reddish edges where it was ripped. On all of the edges there was intricate sewing
holes with a smooth dermal side and one “hairy” side. The sewing pattern has a very distinct
“V” shaped sewed into the left side. Most of the edges were clean cut but the right side was torn.
Specimen 9 was another thin brown miscellaneous leather piece with a yellowish collagen hairy
side and a glossy tanned dermal side. All of the edges were clean cut and had intricate sewing
holes with the same “V” shaped sewing pattern sewn into one edge. Specimen 10 was a fairly
large very thick piece of curved black leather. There were no signs of a clean cut edge, however
one edge had evidence of a rough cut. The “outer” side of piece was smooth and glossy white
the inside was rough and course. On the inside of the bottom edge there is indication of tool
marks.
Specimen 11 was a think yellowish-brown miscellaneous piece of leather. One of sides
had a glossy dermal surface and a “hairy” collagen surface side. One of the edges was clean cut
however the other edges were ripped. One of the edges had been creased back on itself with
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sewing holes to create a clean hemmed edge. Specimen 12 was another thin yellowish brown
miscellaneous piece of leather. One side had a cracked dermal surface and a “hairy” collagen
side. Two of the edges were clean cut and the other two were ripped. At the top portion of the
piece are four large holes equally spread with intricate sewing holes on the left portion.
Specimen 13 was a think dark brown miscellaneous piece of leather. None of the edges were
clean cut, however one of the edges had been folded back on itself and sewn to create a clean
hemmed edge. Pieces of thread are still visible on the hemmed edge with one side being a
smooth dermal surface and the other being “hairy” collagen. Specimen 14 was a thin black
leather miscellaneous piece with one smooth dermal surface and one “hairy” side. All of the
edges were folded back on themselves and sewn to create clean hemmed edges. On one of the
edges, puncture holes that are not uniform to the intricate sewing pattern are visible. Specimen
15 was a think blackish-brown miscellaneous piece with one side being “hairy” and the other
side had a light brown glossy finish that was peeling away to reveal the “hairy” collagen dermal
surface similar to the opposite side. One of the edges has a clean cut curved edge with intricate
sewing holes.
Specimen 16 was a thin brown miscellaneous piece of leather with one glossy dermal
surface and one “hairy” collagen side. One edge has a clean straight cut with intricate sewing
holes. On the finished side, the dermal surface is cracking to reveal yellowish-brown collagen
hairs. Specimen 17 are two intertwined leather straps. These two straps are very thick black
leather that are intertwined amongst one another and knotted together. One of the straps is cut in
the center with the other strap knotted in the slice that was created. All of the ends of the straps
are crudely cut with one side being very smooth and the other “hairy” with collagen fibers. The
smaller strap that is knotted inside of the other strap has evidence of bite marks. Specimen 18 is
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a red leather section with very thin red dyed leather. Both of the sides have a smooth dermal
surface with clean cut edges. One of the edges was folded back upon itself to create a hemmed
edge. The opposite side has a clean cut edge with sewing holes along all of the edges. On the
clean cut edge, there is indication of “lace” marks where the sewing holes indent into the leather.
Specimen 19 is a very thick black piece of leather in the shape of a rectangle with one curved
edge. One of the sides is smoother than the other with intricate punch sewing holes while the
other side has the same puncture sewing holes with piece of thread visible. There are four
separate sewing lines that laterally go from top to bottom parallel to one another. Three of the
sides are clean cut with one side having evidence of a crudely cut/ripped edge. Specimen 20 is a
very yellow semi-thin miscellaneous piece of leather. Two of the edge have evidence of clean
cut edges, however they are torn along the same edges. One of the sides has a glossy cracked
dermal surface while the other side has “hairy” collagen fibers.
Specimen 21 is a leather strap with a metal belt buckle through a hole. The metal buckle
is oxidized and is barley attached to the leather strap with the buckle pin through a hole in the
strap. There is one hole on the end without the buckle with intricate sewing holes about halfway
up the strap. One side of the blackish-brown leather strap is a glossy smooth dermal surface and
one side is “hairy”. Specimen 22 is a small thin black leather strip. The tow ends are torn but all
of the edges are clean cut and the entire strip has a smooth glossy finish. Specimen 23 is another
black leather strip with two torn ends. All of the surfaces were smooth and glossy but the overall
thickness was bigger than specimen 22. Specimen 24 is also a thin black leather strip with two
torn ends. All the surfaces appear to be “hairy” with no finished smooth surface. Specimen 25 is
a medium thickness black miscellaneous leather piece. Both of the sides have a semi-smooth
finish. One of the edges has a clean straight cut while the other three edges have all been torn.
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Specimen 26 is a small medium thick black leather strip. Specimen 26 is thicker than
specimens 22, 23, and 24. Two of the longer edges are clean cut while the other two ends have
been torn. One of the sides is smooth and semi-glossy while the other side is “hairy” with
collagen fibers. Specimen 27 is a thin black miscellaneous piece of leather with one smooth
dermal surface and one “hairy” side. On the right portion there is evidence of a one large hole
and indications of a second whole that was torn in half. None of the edges are clean cut and have
all been torn. Specimen 28 is another thin brown miscellaneous piece of leather. Both of the
sides have evidence of a glossy smooth surface but it has cracked and peeled away to reveal the
“hairy” collagen fibers. All of the edges have been torn giving no further evidence as to what the
piece may have been. Specimen 29 is a portion of a thick black leather shoe sole. One side has a
glossy finished dermal surface. The opposite side is unsmooth with a “fuzzy” cloth that has been
pressed into the surface. It has a clean cut edge that tappers down like the outer edge of a shoe
sole. Specimen 30 is a long thick black leather strap. This is the longest specimen in the
assemblage with two clean cut long edges and two crudely cut ends. Both of the sides do not
have a glossy smooth finish and show collagen fibers. There are four and half holes that are
placed along the strap for a buckle pin to fasten.
DISCUSSION
Each of the pieces in the assemblage has cultural significance in its own unique way.
With each piece one may learn a little bit more about what process it took to achieve the final
product that shines light onto life on a working farm in the Ligonier Valley. Unfortunately some
of the pieces have been so deteriorated that it makes it very difficult to determine what it was
before it was tossed out of the window into the trash pile. Knowledge of whatever they may
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have been may have been lost forever, but as a young, archaeology undergraduate student I can
make a guess to what they may have been as well as the type of animal hide used.
Specimen 1 was the thick leather strap section with different sewing patterns. I believe
this may have been a piece of cow hide because of the thickness as well as a decorative strap
because it was crudely cut into a section that also had no other holes for a belt buckle pin to go
through. Specimen 2 was most likely the sole of a shoe. The smoothness of the underside as
well as the nails as well as the overall curved shape are good evidence to determine this piece as
a shoe sole. Since it also was so thick, I believe this would also was made of thick cow hide.
Specimens 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, and 16 all have very small intricate sewing holes
that gives me the idea that they may have been used for shoe uppers or pieces of glove or a small
handbag. Since they are so thin and intricately made the specimens most likely were made to be
looked at and shown on a piece that wouldn’t go through a lot of damage. They all were
extremely thin that didn’t exceed 1 millimeter in thickness so they were probably made of calf
hide or goat. Specimens 3, 20, and 28 all are miscellaneous pieces of leather that were
unidentifiable. They had no significant markings or holes that would help determine what they
may have been other than just sections of hide. They were all of similar thickness and color
suggesting that they may have been a thin piece of cow hide. Specimen 10 was a thick leather
piece that was curved like the back heel of a shoe. It was oddly crudely cut but also had tool
marks indentations near the bottom that would serve as the connecting part to the sole. Since the
leather was so thick I am assuming it was thick cow hide. Specimen 17 was a very unique and
interesting piece. Both of the leather strips were fairly thick and had preserved well to show the
quality of leather. I cannot determine why these two pieces were knotted together but it was
clearly intentional to possibly connect two pieces to one another. Specimen 18 was the
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extremely thin red leather section I believe this piece was made of pig skin because of the color
as well as the thinness. The lace indentations suggest that the piece may have been a part of a
ball or glove. Specimen 19 was another piece of extremely thick cow hide that had sewing
indentations. I believe this was a section of something that had to put up with a lot of abuse
because of its thickness. Specimen 20 was the yellow miscellaneous leather section. I cannot
determine what it may have been besides a piece of goat hide because of its yellow appearance
as well as its softness. Specimen 21 was a very fascinating piece because of the metal buckle
that was still attacked. There were sewing indentations along the edges that had no real purpose
other than aesthetic appeal. Since it may have been made to look different than a normal leather
strap I believe that this piece may have been a dog collar. Specimens 22, 23, and 24 were all thin
leather strips that could have been used to lash something together or as boot laces. They could
have had many uses but it is too difficult to determine exactly what they may have been used for.
Specimen 26 was a small section of a leather strap. The clean edges give it a uniform thickness
that could have been a small section of a leather strap. Specimen 27 had no clean cut edges that
say that it was a ripped section of hide however the holes in it indicate that it was used to have
laces through it. Specimen 29 was another thick piece of leather that indicated that it could have
been a piece of leather sole. The outer edge was thicker than the rest of it that indicates to me
that it was the edge of the sole. The fabric that had been pressed into the unsmooth side also
indicates that it may have been glued to other sections to make up a shoe sole. Specimen 30 was
a finely made leather strap with four and a half holes for a buckle pin. Since the strip was so
long, I believe it was a long leather strap that had different holes to tighten whatever it was
attached to. All of these assumptions are just educated guesses as to what they may have been
based on the evidence that I observed.
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CONCLUDING OBSERVATIONS
In conclusion, a lot of questions are still present. The different leather sections and
pieces were very interesting and unique and hopefully help provide some more insight into what
life was like on a farmstead in the 19th century. The discovery of the trash midden itself speaks a
lot about how different our culture is and how we have progressed. Instead of having garbage
men pick up what we no longer want, people just threw things that had broken out of the
window. Like I stated in the last section, the original evidence of what the leather pieces may
have been could have been lost forever. All of the identities of these pieces do help show what
19th century Americans used and how the times have changed. This project has helped me pay
close attention to small details that help determine cultural significance in the littlest artifacts. I
hope that these results will help future archaeologists rebuild what life may have been like in the
late eighteen hundreds and early nineteen hundreds.
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25 Miscellaneous Leather 4.5 2 3.3
26 Small Leather Strap 3.5 9 2
27 Miscellaneous Leather 4.2 2 1
28 Miscellaneous Leather 2.7 1.9 1
29 Thick Leather Sole 8.3 2.2 1
30 Long Leather Strap 3.8 2.2 2
*All dimensions were taken at the point of maximum dimension
REFERENCES CITED
Dempsey, M
(1947) The Structure of Skin and Leather. Journal of the Royal. Microscopical Society.
United Glove
Description of Animal Sources Used to Produce Leather. http://www.unitedglove.com/
Pickles, Mary
(2009) "Time Capsule" Unearthed at Ligonier Township Farm." Trib Live
Rotenstein, David
(1997) Leather Bound. Pittsburgh History
How Stuff Works
(2009) Tannins. HowStuffWorks.com.
Richards, Matt
(2000) Tannin and Tannin Sources. Bark Tanning: Tannins and Tannin Sources.
Britannica
(2015) Tannin. Encyclopedia Britannica.
