Finding Historic Foundations with Ground-Penetrating Radar

Historic foundations are perhaps the easiest kind of archaeological feature type to find with geophysical survey instruments–that is, when you are using ground-penetrating radar. Because foundations are usually rectilinear in shape, it is easy to expand a survey area to trace them out, and they are fairly easy to identify in radar amplitude slice maps.

Middle Bass Island Club, Middle Bass Island
Lake Erie, Ohio

In the late 1800s, the wealthy of northern Ohio sought refuge from the summer heat in small communities along the south shore of Lake Erie and on some of the nearby islands. The Middle Bass Island Club was one of these communities. With about three dozen summer “cottages” (these are medium-to-large Victorian homes lacking central heating and kitchens), a large clubhouse, a boathouse, and a large dock for medium size steamers, the club was high-brow enough that it was visited by three sitting U.S. presidents. A large clubhouse served as a hotel for guests and the dining hall for the community. The first clubhouse, built in the 1870s, was quickly outgrown, so about 1881 the “old” building was literally picked up off of its foundation piers and moved up the road, leaving behind a cellar that was filled in. The second and larger clubhouse, a two-to-three story affair, was then erected just a couple dozen feet to the north; again it stood on piers and had a small cellar for kitchen essentials. The club was nearly abandoned in the 1930s and eventually the big clubhouse was torn down. Today, many of the houses remain standing, with updated kitchens and bathrooms, and the former site of the clubhouse is a park-like, privately owned area.

The second clubhouse built circa 1882.

The second clubhouse built circa 1882.

President Taft and other Gentlemen on dock.

President Taft and other Gentlemen on dock.

 

 

 

 

 

 

In the GPR data below three amplitude slice maps, each about 30 cm thick, a variety of different features are visible, none of which can be easily seen at the surface today. In the shallow slice, some pipes and roads or paths are evident. In the middle slice, ceramic pipes are visible to the right and the foundation piers of the clubhouse have appeared, as well as two cellars. In the deepest slice the cellars are the clearest. The cellar towards the bottom of the slices, which has a stair leading out of it to the right, belonged to the first clubhouse built in the 1870s. The second, rectangular cellar was underneath/adjacent to the kitchen of the second clubhouse built in the early 1880s. 

three_slices_from_tot3
In this view (below) the radar data in the clubhouse area are positioned on a map of the southern end of the club property. Many of the houses are still standing today, though the dock and the dockhouse are now gone and the seawall has succumbed to the relentless bashing of Lake Erie’s winter storms. 

closeup_of_radar_on_club_map