John Foellmer of Colesville prepares to clean a set of artifacts from a Montgomery County archaeological site. At a recent lab session at Needwood Mansion’s archaeology lab, volunteers recorded finds from the historic Josiah Henson site in Bethesda. (Elizabeth Waibel/The Gazette)

Working slowly and with practiced care, Kathleen Knox gently sorted glass shards, bits of old brick and stray pieces of plastic from a nearby archaeological dig into separate piles before cleaning them. A magnet helped her separate the metal items, some of which were so caked in mud that nails looked like twigs.

Knox, a Brookeville resident, was one of several volunteers working at the Maryland-National Capital Park and Planning Commission’s archaeology lab in Needwood Mansion in Derwood on Dec. 4. She rinsed some artifacts in a pan of water and used a toothbrush to clean the dust off others. She used small tools to pry mud from grooves and indentations in a few pieces. It’s a slow, meticulous process, but it lets her clean the artifacts without damaging them.

“You don’t want to throw something that shouldn’t be in the water [into] the water; you just brush it,” Knox explained. “Old brick will just dissolve. . . . You don’t want to lose the substance of what you’ve got.”

Knox started volunteering at the lab after taking an archaeology class at Montgomery College in Rockville.

“I’ve always been really interested in archaeology, and I didn’t have any time until . . . I retired,” she said. “Many of the volunteers came here because of that class. It’s fascinating.”

The class, called 12,000 Years of Montgomery County’s Past, is offered in the fall and spring semesters through the college’s Lifelong Learning Institute. For the first class session, participants learn archaeology basics. During the remaining four sessions, in the field, students learn how archaeologists determine the age of a site and verify their finds.

Vivian Eicke, children’s archaeology camp director for M-NCPPC, is a teacher for the class.

“We take them on tours of various sites in the county,” she said. “We do at least four different sites. . . . We try to do it from prehistoric, [then] 18th century . . . even into the 20th century.”

Many of the former students, such as Knox, continue to explore the field by volunteering to help with events or catalogue finds. Parks Department archaeologists host lab sessions on the first Tuesday of every month. They also offer summer workshops for children and adults and partner with other archaeology groups in the area, including the Mid-Potomac Chapter of the Archaeological Society of Maryland and the archaeology club at Richard Montgomery High School in Rockville.

During this month’s lab session, volunteers sorted and recorded finds from the Josiah Henson site in North Bethesda. Henson was a slave in Montgomery County before escaping to freedom in Canada, and his autobiography inspired Harriet Beecher Stowe’s anti-slavery novel “Uncle Tom’s Cabin.”

Cassandra Michaud, assistant archaeologist with M-NCPPC, picked up a fragment of a ceramic dish, less than the size of a coin, with glaze visible on two sides.

“This was somebody’s dishes,” she said. “This one looks like it has a decoration on it.”

Although the shard of broken dish is small, researchers can study the glaze and clay to determine roughly when it was made. With information gleaned from other bits and pieces left behind by the site’s earlier inhabitants, researchers can assemble a picture of what life was like in 19th-century Montgomery County.

Even at the beginning of a long process of cleaning, sorting and cataloguing the artifacts, Knox can learn about the items’ previous owners. Under the floorboards of one old house, archaeologists collected pieces of large bones that probably had been cut during cooking, bird bones and oyster shells.

“Oysters were a huge part of the diet in this part of the country,” Knox said.

Michaud said archaeologists spend much more time in the lab than in the field.

“There’s a feeling that archaeology is about excavating, and it is, but . . . for every day on the field, it’s seven days of doing this kind of work — to take care of those artifacts, to wash them, to catalogue them, to write the report, to analyze them,” she said. “As fun as digging is, there has to be a reason, and it has to go somewhere.”

The artifacts from the Henson site will become a resource for researchers studying the area’s history. They will also help in the development of a museum at the site about Henson’s life. Most of what is known about him comes from his autobiography, Michaud said. Through the long process of excavating, preserving and studying, archaeologists and historians can piece together some details of Henson’s everyday life.

“All of this work that’s going on here with all these volunteers will feed into that interpretation, so we have a picture of the past,” Michaud said.

For information about archaeology in Montgomery County or to volunteer, visit or call 301-840-5848.