Oyster Wars


A sample of oyster shell recovered at the Cumberland site (18CV171), a Native American palisaded village in Calvert County.

When most people think of Maryland seafood, probably the first thing that comes to mind is the blue crab, steamed to a bright red and fragrant with Old Bay seasoning. But the “lowly” oyster played just as significant a role in Maryland’s maritime history and economy. Although it may have been a “bold man that first ate an oyster” (Swift 1738), any initial squeamishness toward the bivalve was quickly overcome by humans, who have dreamed up more ways to serve an oyster than Forrest Gump’s business partner envisioned for shrimp. And it also happens that the Chesapeake Bay and its tributaries have historically provided the appropriate water temperatures and salinity levels that allowed Eastern oysters (Crassostrea virginica) to thrive (NOAA 2013). Continue reading

Welcome Virginie!

New conservator, Virginie Ternisien, comes to us on contract for a year from France where she recently graduated from Paris 1 Pantheon-Sorbonne University with a Masters Degree in Conservation and Restoration of Cultural Property. During her studies, Virginie had internships to conserve artifacts from the Museum of Orsay and the Louvre. She has also been involved with conservation projects at the British Museum, the Clemson Conservation Center in South Carolina (home of the Hunley), and in Egypt and Albania. Virginie is currently pursuing a Research Masters in conservation with a special interest in composite objects and, at the MAC Lab, she will be primarily responsible for treating artifacts from the Presidio La Bahia, a Spanish frontier fort located in Texas.

Using a scalpel to remove corrosion from a kettle found
at Presidio La Bahia.


What is That?

It started as an unidentifiable mass and ended up being a rather rewarding conservation project. A heavily concreted lump of metal was found at an 18th-19th century site located on the Aberdeen Proving Ground, a United States Army facility located near Aberdeen, Maryland, in Harford County. The object was taken to the MAC Lab (along with the other artifacts from the site) and x-rayed as the first step in the conservation treatment process. The x-ray showed that the metal lump was an iron chain solidly encased in corrosion material. Conservator Cait Shaffer undertook the labor of freeing the chain. After 40 treatment hours, each link of the chain was separated from the concretion and the artifact was fully conserved. According to Cait, freeing the chain links was time consuming but quite satisfying.

The concreted iron chain before treatment.

X-ray of chain.

Chain during conservation treatment.


Courtesy U.S. Army Garrison, Aberdeen Proving Ground

Artifacts from a 19th-Century Chesapeake Bay Schooner

Ship parts from the Widgeon, a bay schooner, were found during a 1997 archaeological investigation of St. Leonard Creek and are currently in the conservation department at the MAC Lab. A schooner is a type of sailing vessel that was originally used by the Dutch in the 16th and 17th centuries. By the early 18th century, however, schooners were used more extensively in the United States than anywhere else in the world. Used for everything, from privateering to offshore fishing, the most common schooners had two masts. One of the objects recovered from the site of the Widgeon is a hoop of iron that would have encircled one of these masts. This “mast band” would have been used as reinforcement for the wooden mast and also would have served as a place to attach ropes and tackle. Conservation of the Widgeon’s 19th-century artifacts has taken several years and the mast band is one of the last objects still in treatment.

Iron mast band still attached to remnants of the wooden mast.

View from the deck of the Widgeon.

*FUN FACT: After the Civil War, Maryland opened the Chesapeake Bay to oyster dredging. The use of dredges, versus tongs, created a need for larger, more powerful sail boats to haul the dredges across the oyster beds. The first vessels used were the existing schooners, like the Widgeon. Eventually, the bugeye was developed specifically for oyster dredging in the Chesapeake Bay.

Neither Snow nor Rain nor Heat…

…nor gloom of night stays these archaeologists from the completion of their appointed…er…excavations. Although it’s cold outside, archaeologists keep right on excavating until the ground freezes and lately, even in the snow, the crew has continued working at the Smith’s St. Leonard site on JPPM property. An interesting feature at the site that has attracted their attention this winter is an enormous posthole in the area of a colonial horse stable. A posthole is a feature cut into the soil used to hold a surface timber supporting a structure. There are many postholes at the Smith St. Leonard site, because the site consists of quite a few buildings, but the posthole currently ‘WOWing’ us is 6 feet long and over 4 feet deep and is the biggest that many of the archaeologists at the Park have ever excavated. Since this hole is located in the stable area, it is possible that the post was really large because it helped to carry the weight of a hay loft on a second floor. While working very hard to excavate this monster, the archaeologists discovered wood from the original post. The wood was in bad condition after being in the ground for 300 years, so conservators were called in to stabilize the wood until it can be removed.

Yup, it’s cold.

Conservator stabilizing the remaining wood inside the posthole.

*Look for the next blog detailing the conservation treatment used on the wood…

New “Back to Back Tours” at JPPM

Cold? Would you like to come inside where it’s warm and learn a bit of history? JPPM is currently in its off-season (the Park and all its activities will re-open on April 16th of this year) but, we are offering special combination tours of the Patterson House and the Maryland Archaeological Conservation Laboratory all year round on the 1st Wednesday of every month – AND you can enjoy these 2 guided tours for the price of 1 ! Now that you are finished caroling and cutting down that tree, come on inside and learn about history and science at JPPM. The fee is $10/person ($8/Seniors, Age 55+). Reservations are required. Please call 410.586.8501 or email jppm@mdp.state.md.us

The Patterson Estate, country home and retreat

Visitors on a tour of the MAC Lab

Air Abrasion

Along with other cleaning methods, conservators often use air abrasion to clean the corrosion off metals and to reveal surface details on an artifact. With the air abrasion method, air and an abrasive are discharged through a tube onto any corrosion covering an artifact. The corrosion is worn away by means of friction. The abrasive can be anything from tiny glass beads to powdered walnut shell, and each varies in coarseness. Iron artifacts from the Dover Bridge site in Talbot County are only a few of the objects that have been treated by air abrasion at the MAC Lab recently. Dating to around 1700, these artifacts include axes, a hoe, knives, scissors, nails, a door lock, and a smoker’s companion.

Conservator using a small air abrasion unit

Removing corrosion from a small object

Iron hoe from the Dover Bridge site before treatment

Same iron hoe after treatment