``I've got one," Russell Kempton said, after running a lawnmower-like contraption over a five-foot stretch of grassy earth.
``Oh, good," answered Russell Horne as he hustled over with a fistful of foot-long metal stakes, knelt down, and jabbed one into the ground. With a few whacks of a hammer, the metal disappeared underneath the grass. Only the pink plastic ribbon tied around the spike head was visible.
The pair repeated those motions 124 times in four hours on one recent morning , each time marking another long forgotten body.
So far, 321 unmarked graves have been discovered in Southborough's Old Burial Ground. That's two more than are marked by headstones -- and the search has just begun.
``It's fascinating to say the least. You wonder if they thought back then we'd be worrying about them 150 years later," said David Falconi , president of the Southborough Historical Society and a member of the Historical Commission.
Kempton, a geologist with New England Geophysical of Mendon, was awarded $3,000 by the Historical Commission in July to use his ground-penetrating radar to search for unmarked graves in the three-acre cemetery, located on Common Street behind the library.
Kempton has scanned only a handful of cemeteries and most of them out of state, including a 17th-century burial ground of English settlers and Native Americans at Fort William Henry in Maine.
The graveyard only has 319 stone markers, but town records show 819 definite burials and 307 possible burials.
The Hurricane of 1938 is believed to have uprooted several trees from the cemetery and destroyed dozens of stone markers that were never replaced.
``There's some 1,100 people buried here and many that don't have stones," said Horne, a Marlborough resident whose family helped found Southborough. Horne, who sits on the Historical Society board of directors, believes he has at least a dozen ancestors in the town resting place. ``It's always been a question of what happened to all those stones."
And Horne's relatives are probably latecomers to the grounds. The cemetery has long been believed the site of a burial ground for the Nipmuck tribe of Native Americans, who lived in what later became Southborough, according to Fences of Stone , a book on the town's history by resident Nick Noble .
Verifying that native burial ground indeed exists in the southern section of the cemetery will be the last part of the project. Kempton will use a three-dimensional radar imaging system that can -- via computer -- peel back layers of the soil. A preliminary scan has already shown signs of a large hole that spans 20 feet.
``I did see a bowl-like delineation," Kempton said. ``This is not naturally occurring. There was an excavation here at some point in time."
If a site is discovered, the Massachusetts Historical Commission would have archeologists investigate, with the Commission of Indian Affairs monitoring.
The land became the town's official burying ground just months after Southborough separated from Marlborough in 1727, according to the historical society. The graveyard was declared full in 1842 after all the plots were reserved and the Southborough Rural Cemetery opened farther south on Route 85. The last burial there was in 1895.
``I think in the end we'll find almost every one," Falconi said of the just about 800 unmarked graves believed to exist.
Members of the Historical Society will return to the burial ground Tuesday morning and pick up where they left off . There are five sections to the cemetery running from north to south, and only the most northern section has been thoroughly searched. Since Sept. 19, they've spent three four-hour sessions at the graveyard.
``As we go we're finding interesting tidbits that are going to take some research," Falconi said. ``The more you find out the more it creates more questions rather than answers."
They have come across grave sites that appear to include two adults or an adult and a child; the foundation of what may be an old powderhouse; and signs of what could be headstones a foot underground in two sections of the cemetery.
``It's like they were just piled there," Falconi said of discovery in the northeastern most section of the cemetery. ``That makes sense. There were 38 or 40 stones broken in the hurricane."
The discoveries are courtesy of a box-shaped device with a computer screen on two wheels.
An antenna sends a pulse of high frequency radar up to 12 feet underground, which is echoed back and recorded by the machine in real time. A computer screen near the handlebars displays the results.
``We're looking for an anomaly in the naturally occurring soils," said Kempton, who once worked for NASA designing remote sensing systems. ``It's an easy jump to infer you're looking at grave shafts."
When a body decomposes, it increases the organic matter in the soil and leaves a rectangular trace that radar can detect. In addition to the organic matter, the radar picks up changes in the soil made when the graves were dug.
"Soil doesn't change by itself," Kempton said. "When you dig stuff up and put stuff in the ground the soil doesn't go back to the way it originally was."
All the remains in the cemetery decomposed long ago, nourishing trees that have sprouted above them.
The graves show up on the computer screen in vibrant reds, purples, and yellows that narrow at each tip.
Typically only six inches to one foot wide, the graves start roughly four feet below the surface and span five feet in depth, according to calculations by Kempton, who typically uses his device to help police find evidence and municipalities locate pipes.
A scan of the entire cemetery should be complete within a month. Then members of the Historical Society and Historical Commission will comb through the data and draw up a report, Falconi said.
The information will be used to update a map of the cemetery that dates from the 1970s. An enlarged version of that black and white map is carried to the cemetery for each session and updated with red dots to mark the locations of the newly discovered graves and their metal stakes -- chosen because they can later be picked up by metal detector.
In the end, Falconi said he hopes a permanent plaque or memorial can be erected in the cemetery to commemorate all the souls who would otherwise not be identified.
``We don't know who these people are. Probably in 100 years there will be some kind of technology to identify them and link families. For right now we just want to find them and end up with some kind of marker," he said.
Looking up at the bright blue sky and the tall leafy trees that encircle the quaint cemetery in downtown, Falconi declared with a smile, ``Not a bad place to spend eternity."
Jennifer Rosinski can be reached at email@example.com.