Preston — Volunteers from across the state made their way to the secluded Long Society Meetinghouse Tuesday for the start of a four-day archaeological dig that also will serve as an old-fashioned foundation excavation project.

A recent structural analysis of the early 19th-century meetinghouse resulted in a recommendation to remove soil that had built up at the rear right corner, causing the wooden frame and siding to rot.

But with some gravestones in the surrounding colonial-era cemetery standing just a few feet from the building’s edge, a backhoe could damage gravestones and possibly disturb burial plots.

About a dozen volunteers, including members of the Friends of State Archaeology and the Preston Historical Society and local residents were joined by seven students from Farmington Alternative High School under the direction of State Archaeologist Brian Jones to dig around the foundation by hand.

The workers will remove about 3 feet of soil against the building, exposing the fieldstone foundation that has become buried. Then they will dig a narrow trench to direct water away from the building toward the stream down the hill behind the building.

“Whatever we’re doing is much more delicate than what a backhoe would do,” Jones told two volunteers working in the corner section of the building after they expressed concern about disturbing the ground.

Workers were instructed to dig to 10 centimeters down and mark whatever they found on a corresponding paper grid. Nails, pieces of glass and any interesting-looking stones were collected in plastic bins. They dumped the dirt into buckets to be carried to a sifting station halfway down the hill.

Friends of State Archaeology members Emily Zepp of Windsor and Lori Kessel of Storrs worked in the corner where the ground was highest against the building. After an hour of digging, the two had found several hand-wrought nails and some bottle glass.

Along the back wall, diggers were curious about the number of window glass pieces they had found. The entire back wall has only one fairly small arched window. Jones speculated the glass was from window repairs over the past two centuries — mostly modern glass in the top layers of dirt.

“If we see blue-green window glass, that would be older,” Jones said.

The excavation is the start of what could end up being an $180,000 restoration project by the Preston Historical Society to restore the meetinghouse, built in 1817 and opened in 1818.

Retired state Archaeologist Nicholas Bellantoni made the Long Society dig his first field work this year as a volunteer under his successor’s direction. Bellantoni said he had worked with Preston Historical Society President Linda Christensen during the past several years as the society worked to secure ownership and trace the history of the building.

“It’s good to get out and help Brian out,” Bellantoni said. “I was here with Linda, so when I heard what they were doing, I said, ‘I had to get out here.’ It’s a good project.”

c.bessette@theday.com

Twitter: @Bessettetheday