Ground Penetrating Radar
At the Walker-Blake Graveyard, we have some people whose burial location is not known because their gravestone marker is missing. It’s a mystery! In August of 2007 I read an article on Ground Penetrating Radar (GPR) and contacted the author who is Associate Professor Lawrence B. Conyers of the University of Denver. I asked about his usage of GPR for finding burials, gravestone markers and performing archeological work. Although GPR seemed to show some promise in locating missing burials and gravestone markers, I was concerned about the costs of a team coming from Denver to work a Taunton’s Walker-Blake Graveyard. I put the idea on the back burner.
In June of this year I was surfing the web for GPR in Massachusetts and found the Nemasket Hill Cemetery (in Middleboro, MA) website http://www.nemaskethill.com/. The website had a story about the GPR work being done at the cemetery by Bob Perry, Director of TopoGraphix from New Hampshire. The oldest cemetery in Middleboro was embarking on the latest method of mapping which will include satellite images, GPR surveying and laser distance measuring. Given the historic significance of Nemasket Hill Cemetery and the unique topography involved, Robert Perry's expertise in specializing in historic burial site studies was important for preserving history for future generations. I contacted the Nemasket Hill volunteers and found the work was underway. I did not come across TopGraphix in my early research. From my research I found that earlier usage of GPR had mixed results and there are many variables, but I thought it was time to have some limited GPR done at Walker-Blake Graveyard.
What is GPR? Ground Penetrating Radar (GPR) Mapping is subsurface imaging that literally looks underground to develop a picture profile of what lays below the surface. GPR is used to determine the location of unmarked graves, burial vaults and
Walker-Blake Graveyard has missing grave locations. We have recorded gravestone inscriptions from the 1800’s and 1972 that were documented but some markers are missing. We have done some probing and have uncovered quite a few markers but there are still several markers missing. We have created a map of the graveyard. The map locates each headstone and footstone and a unique number has been assigned to each marker. We made a spreadsheet listing the names of all those who are buried in the graveyard. The spreadsheet was compiled by transcribing the information that is recorded in the “Inscriptions from the Burying Grounds in Ancient Taunton” collected by Edgar Hodges Reed b. 3 July 1814 d. 25 April 1893 (the date of the compilation is not known) and “Inscriptions from Eleven Cemeteries in Taunton” Compiled in 1973 by Mrs. Wendell B. Presbrey Historian Lydia Cobb Chapter Daughters of the American Revolution. After creating the spreadsheet, I compared the recorded names between the two listings. The comparison is limited because the E.H. Reed recording did not include any burials in the 1800’s. At the time, he must have considered these burials the recent burials and not requiring the attention. There are 13 people who are listed on the Reed list are not recorded on the 1972 Presbrey list. So, in 1972, the grave markers were missing or somehow not accounted for. From the 1800’s, there are 4 people who are listed on the Presbrey list whose markers are missing. The total number of people who are currently buried in Walker-Blake Graveyard are about 164.
Prior to 1923, Walker-Blake Graveyard was the final resting place of 12 other people. But in 1923, there were removed from this burial ground to the South Dighton Cemetery, the remains of twelve of the earliest ancestors and kindred of the Baylies Family in America whose names are here inscribed.
Thomas Baylies, Jr.
Thomas Sargeant Baylies
The reason why these people and their gravestones were removed was because Mrs. Baylies was concerned about the remote location of the graveyard and possible vandalism of the markers. This was in 1923. She had good reason to have concern!
The total number of people who are known to be buried and have missing markers is 17.
We contacted Bob and after discussing scope of work and pricing, we set July 17, 2009 as the date to perform the GPR survey. The day of the GPR survey was clear and in the temperature was in the 80’s. Bob Perry drove up to the graveyard in his pick-up truck and off loaded his instruments and gear. I had previously determined an area of the graveyard that seemed to hold the most promise for locating missing burials and grave markers. Every aspect of this work is very scientific. First, we measured off the area to be surveyed and put stakes in the ground at each corner. The overall size was 90 ft x 64 ft. Next, we had to lay down rope in 90-foot lengths and 4 feet apart to create a grid and lanes for the GPR instrument to follow. By laying out the grid you insure complete coverage of the entire area by the GPR. With the preliminary work done Bob assembled the 3-wheel GPR machine with an onboard computer. As Bob pushed the machine, the GPR, which could move up and down, slid over the terrain and sent information to the computer and displayed images on the screen. The screen shows a cross section of the ground with distant traveled read across the top line and the depth measured shown on the left side. As the machine is moved, a measuring device on the front wheel sends distance traveled to the computer. The radar waves can penetrate the ground 8-10 feet and bounce back. The layers of dirt that have not been disturbed are shown on the screen as flat lines. A burial shaft is shown as a hyperbolic curve because the soil was disturbed. Usually, when you see the hyperbolic curve on screen there is also some small white spots which indicates voids or air spaces. These air spaces may indicate skeleton remains. No, you do not see any bodies! After surveying the entire area, Bob then went back and resurveyed the possible unknown burials in the opposite direction to find out if the possible burials were of a “high confidence” or not confident. At the end of the day, there were close to 50 locations flagged as possible unknown burials but there was more work to be done. I was surprised by the number of findings but disappointed the survey did not find any missing gravestone markers. I had expected to find maybe 5 fallen over and covered gravestones. Bob went back home to review and analyze the results and review 3-D models that were generated from the survey. A few weeks later, Bob sent the results: 24 “high confidence” locations and he found a headstone! We were concentrating on the screen at the 4- 6-foot depths and did not initially notice the abnormality near the surface which indicated a possible gravestone. I plan to go back to the graveyard in September to see if I can uncover the missing gravestone and see who belongs to it. Another surprise was that 3 of the high confidence burials are very close to the stone wall, within a few feet. Makes you speculate that the burials predate the building of the stone wall and if that is the case are there addition burial under or on the other side of the stone wall. The overall results were very good, and I look forward to having additional GPR work done in the future. We plan to install small metal numbered markers at the locations of the possible burials for mapping and records purposes.
In the coming months, we have a lot of studying to do of the information. Besides the graveyard map and spreadsheet, based on the spreadsheet names, we have a family tree/ genealogical chart of the Walkers and Blakes and people who married into their families and their children. Over five generations! The chart is so complete that only a few people appear not to be related but may have been a friend of someone buried in the graveyard. (For a copy of the chart see www.Walker-BlakeGraveyard.org). So by looking at the possible burial and seeing the name of who is buried close by and seeing whose marker is missing and looking at the family tree chart, then by process of elimination, we may be able to deduce who is buried at a specific high probability burial!