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The three square miles of property at Monmouth Battlefield State Park, if excavated with traditional 5'x5' squares, require
about 3.3 MILLION squares and would take about 3,000 years to excavate. Call us impatient, but we didn't want to wait that
long, so we're utilizing modern technology to get the job done quicker. With so much area to cover and over 220 years
of disturbance to contend with, we begin by attempting to "see" beneath the surface without actually breaking ground.
This is done two ways: with Surface Penetrating Radar (SPR) units and with metal detectors.

An SPR unit is the most sophisticated type of surface penetrating system available and can detect anamolies over 30 feet deep
with clear resolution. Originally developed in Britain to detect plastic land mines, an SPR system can not only locate disturbances
underground, it also provides a signature that can give the user clues that will help him identify each disturbance. While
some battlefield archaeologists use a different system of ground penetrating radar, to date Monmouth Battlefield is the only
U.S. battlefield utilizing this advanced technology for archaeological purposes.
BRAVO also conducts systematic metal detecting surveys of specific areas, utilizing our "Bag, Tag, and Flag" system.
Each artifact we discover is put into a bag, given a number, and put back into the open hole with a flag to mark the spot.
Once all of the metal detecting work is completed, these flagged artifact locations are pinpointed and recorded using Total
Station (laser transit) or, if Total Station is unavailable, we use a compass and tape measure from a known point. Finally
the artifacts are collected and the holes refilled.
The next step is to plot the artifact locations into a CAD (Computer Aided Design) system, which reveals important information
such as patterns of fire. Once we have the artifact locations plotted into CAD, we can go one step further and create layers
of artifact types within CAD. By doing this, we can choose to bring up a screen of only one specific type of artifact, such
as chewed musket balls, in order to clearly determine where a field hospital might have been located. Think of layered CAD
images like computerized transparencies where the viewer can add or take away layers of images in order to focus on one specific
thing.
We've excavated three sizes of musket balls at Monmouth Battlefield: 0.693 inch diameter balls from the British Brown Bess,
0.65 diameter balls from the French Charleyville, and although there were several sizes of American musket balls, the most
typical was 0.60 inches in diameter. In addition, there are three conditions musket balls are found in: they could be chewed
or mutilated, indicating a surgery site; impacted, indicating that the fired ball hit a target, whether human or otherwise;
or dropped, wherein the ball is still perfectly round and was simply dropped from a soldier's pouch.
A new problem arose when finding these musket balls: while it was easy enough to measure dropped balls, how can we determine
the size of an impacted or chewed musket ball, which can be so misshapen that it may resemble a flattened piece of chewed
gum more than a ball? That's where Dan Sivilich's engineering background blended with his knowledge of archaeology to come
up with a formula that has given battlefield archaeologists a way to answer this crucial question. It's called the
Sivilich Formula, which was published by the Society of Historical Archaeology in 1995. The formula is a combination of physics
and chemistry that calculates the original diameter of any nonspherical musket ball. The resulting data can be used to show
clusters of calibers that represent concentrations of enemy fire, among other things.
The accuracy of the Sivilich Formula proved itself out when it correlated with an account left by Joseph Plumb Martin, one
of the soldiers who fought in the Battle of Monmouth. Martin's narrative acounts of his experiences in the battle are presented
in a book called "Private Yankee Doodle". In the book, Martin speaks of British and American artillery placement
and troop movements in relation to topographical features. He also details the location of a specific British soldier he shot.
When Sivilich compared this account to his CAD images, he was amazed at how accurate the images were. Not only with regard
to movement of troops and location of artillery, but even the spent bullet Martin said he fired at a particular British soldier
had been found in the same spot. Where Martin refers to an area with wounded soldiers, CAD showed a collection of chewed musket
balls.
Now that we're able to correctly interpret history, Monmouth Battlefield's past will become its future. The site will be rehabilitated
to its 18th century plantings, which will help us interpret the battle even further as it educates visitors in the history
of their community. As SPR units detect root zones of individual 18th century trees, apple orchards are already being replanted.
In addition, it is an official goal of the New Jersey State Division of Parks and Forestry to turn the battlefield into a
world class park, complete with tour roads and wayside exhibits.
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