We are in
the final stages of processing the 2015 Fort Hunter collection and have begun
to inventory the artifacts. As described in our Processing the Fort Hunter
Collection blog the inventory process includes, “adding
a description of each artifact or group of like artifacts into the digital
inventory by catalog number, and bag and box them carefully to insure their
preservation for long-term curation. This is all done in a systematic manner so
that any given artifact can be easily accessed and utilized by future
researchers.” During this process we try to add as much information to the
inventory as we can that may be useful to a researcher and for us in our site
analysis. This includes material types,
condition or wholeness of the artifact, and date of production to name a few.
Many of these characteristics are easy to identify just by looking at the
artifact, but determining the date or date range of production is not always
easy. Over the years archaeologists have identified different methods on how to
date different types of artifacts. We will take a look at some of these techniques
here.
Typologies
After years of research through
historical documentation and through precise data collection from well
stratified and dated archaeological sites, archaeologists have developed
typologies for several different categories of artifacts such as ceramics, pipe
stems, bead, projectile points and more. A typology is a system that uses
physical characteristics to place artifacts into specific classifications. In
the case of a dating typology archaeologists use the physical characteristics
to identify the artifact within a specific type that correlates to a specific
date or range of dates.
Ceramics
One example of this analysis method is historic ceramics which have been
in production for hundreds of years, but not every type of ceramic has been in
production for that entire period. Due to technological advances especially
during the mid-16th to mid-17th centuries, pottery craftsmen
were able to create more refined pastes (less porous), glazes more purified in
color and new methods of decorating the pottery (from hand painted to transfer
printed) as time went on. It is these changes in how the ceramics were produced
that created subtle clues to help the discerning eye determine the specific
type of ceramic. In the case of ceramics it can be difficult to identify
creamware from pearlware, whiteware and others, but through previous research
we know that the paste in creamware is more porous than that of the others and
that the glaze is often pooled with a green tint in crevices. It is often these
physical attributes that help identify a specific ceramic as creamware. Once we
have identified the piece as creamware we can then look at known production or
manufacture dates from the typology and determine a date between 1760 and 1820
(Deetz 1996).
Ceramic typology on exhibit in the archaeology section department of the
State Museum
When we have an entire or even a large fragment of a ceramic vessel, we can often determine the shape of
the vessel or the type and method of production of the design on the vessel. Both
of these characteristics are also used to narrow down a date range. So not only
do we have a typology based on the type of ceramic, but we also have typologies
with determined dates of manufacture for each of the different shapes and forms
of decoration. Researchers comb through
archives for manufacturing records which also aid in dating these historic
period ceramics.
Prehistoric Pottery & Projectile Points
Dating methods for prehistoric ceramics are dependent on typologies
which were developed through careful analysis of such attributes as temper,
decoration, design and form. For many native groups’ specific tempers, forms,
designs and/or decorations have been attributed. Through many years of work on
archaeological sites of different specific native groups a typology of pottery
has been developed. Today many vessels can be easily identified with the use of
this typology because there are so many different styles, each of which is
attributed to different culture groups and periods. This is true of large
fragments or whole vessels, but when it comes to small fragments with limited
design or decoration on them, like using the porosity of the paste in historic
ceramics. Archaeologists must use the temper type to determine where the
pottery originated or if it could help identify what group occupied a site when
combined with other evidence. Temper is a material foreign to the clay which is
added to help prevent the vessel from cracking or breaking during the drying
and firing processes. Common
Pennsylvania tempers include chert, quartz, limestone, shell and more.
Example of pottery
fragments with varying temper types. From left to right shell, quartz and chert
The same process of collecting
data from various sites over many years has also provided archaeologists with a
projectile point typology. These typologies like that of the prehistoric
pottery vary from region to region, but each typology is developed using the
shape, size and lithic type of projectile points and context in which they were
recovered.
Part of the
projectile point typology on exhibit in the archaeology section department of
the State Museum
Glass Bottles
As with historic ceramics, archaeologists have developed typologies of
glass bottles based on various physical characteristics. One part of the
typology looks at the bottle lip or rim. Several types of lips were put onto
glass bottles using different methods. So, as with the ceramics, archaeologists
can attribute different lips to a date range because as new technologies or
methods of attaching lips to bottles were developed other methods were outmoded
and the newer methods were used more frequently. This is also the case with the
form or shape of the bottles. The shape of the bottle base changed over time as
push-ups became more or less popular and round versus oval came in and out of
use. There is also the use of molds, which leave mold seams on the glass that
provide archaeologists with another dating tool. Finally, if a bottle has a
seal or is embossed with a company name, archaeologists can find information
relating to that company to determine the bottles time range of
manufacture. There are many ways we can
date a bottle and for more in-depth information on this process please check
out the Society for Historical Archaeology’s website at https://sha.org/bottle/index.htm.
Picture of various
glass bottles courtesy of SHA bottle identification website
Picture of various
bottle base types courtesy of SHA bottle identification website
Picture of a bottle
with a push-up courtesy of SHA bottle identification website
Pipe stems
Another example of the use of a
typology to determine the production date of an artifact is white clay smoking pipes,
referred to as kaolin or ball clay pipes. In the case of pipe stems as with
many artifacts, it is the advancement or change in technology and form that
allows archaeologists to develop typologies. Based on historic documentation
the length of pipe stems increased as time went on and in order to bore a hole
through such long stems with no damage to the wall of the stem the size of the
wire used to bore the hole had to decrease (Hume 1969). After a study of
thousands of pipes both American and English one Mr. J.C. Harrington developed
a system showing average bore diameter size and its correlating production date
(Deetz 1996, Hume 1969). Today this system though still in debate about its
accuracy, is widely used to determine the general date ranges of pipes with
attached stems and pipe stem fragments, which provides useful information about
the use of a site during different periods.
Diameter
|
Dates
|
9/64
|
1590-1620
|
8/64
|
1620-1650
|
7/64
|
1650-1680
|
6/64
|
1680-1720
|
5/64
|
1720-1750
|
4/64
|
1750-1800
|
Picture comparing 4/64th,
5/64th and 6/64th pipe stem diameters
As shown above there
are many different typologies that archaeologists have developed in order to
help us date artifacts and thus date different levels of sites. Those mentioned
above are just a few of the typologies archaeologists use there are also bead,
drinking glass, button, coin and many other historic artifact typologies as
well as prehistoric artifact typologies such as projectile points and pottery. There
are also ways to help narrow down dates to more definite ranges with the use of
maker’s marks.
Makers Marks
A maker’s mark is basically a logo or trademark, which can include
images, words, initials or dates that represent the maker of the product on
which the mark is placed. These marks were placed on all kinds of products
including glass bottles, ceramic vessels, various forms of metal objects and
many other types of artifacts. Through registries and historical research it is
now possible to find published lists of maker’s marks for both American and
English companies, which show images of and describe maker’s marks and provide
the date range of production for anything with that mark.
Picture of maker’s
mark on artifact with image and date from documentation
Identifying the dates
of manufacture of artifacts helps archaeologists to not only date the level of
a site, but also understand the use of the land during that period. Doing this
also allows archaeologists to compare sites with similar artifacts and dates to
find similarities or dissimilarities that can help us to develop theories on
types of sites and their use.
We hope you have enjoyed this look into the analysis and research
methods employed by archaeologists and will consider reviewing some of the
resources listed below. Our job as archaeologists and curators offers us a
unique opportunity to examine archaeologically recovered specimens and create a
picture of past human behavior through our material culture. Please visit our
gallery of Anthropology and Archaeology on the second floor of The State Museum
of Pennsylvania where you can view additional artifacts representing our
archaeological heritage.
References and additional
information:
Deetz,
James
1996 In Small Things Forgotten: An Archaeology
of Early American Life.
Anchor Doubleday, New York.
Hume, Ivor Noel,
1969 A
Guide to Artifacts of Colonial America. University of Pennsylvania Press,
Philadelphia.
