New England’s abandoned stone walls are as iconic of the region as lobster pots, town greens, sap buckets and autumn leaves. They seem to be everywhere; a lattice of dry, lichen-encrusted stone ridges separating a patch of otherwise moist soil.
Stone walls can be found here and there in other states, but in New England alone they are found almost everywhere. This is due to a regionally unique combination of hard crystalline bedrock, glacial soils, and small land parcels of farms.
It was almost entirely built by European settlers and their pack animals; These stones were thrown from agricultural fields and pastures towards fence lines and borders, and then thrown or stacked in the form of ropes. Although the oldest walls date to 1607, most were built during the agricultural era between the American Revolution and the cultural shift toward cities and industry after the Civil War.
The mass of stones carried by farmers in that century confuses people; An estimated 240,000 miles (400,000 kilometers) of roadblocks are stacked, most of them thigh-high and just as wide. That’s long enough to wrap our planet around the equator 10 times, or to reach the Moon at its closest point to Earth.
Naturalists are working to measure this phenomenon, which is larger than the Great Wall of China, Hadrian’s Wall in Britain and the Egyptian pyramids at Giza combined. This study began in 1870 and formed the U.S. government’s 1872 Fence Census. Today, scientists use a technique called LiDAR, or light detection and ranging, to measure and map stone walls in New England.
As a geologist, I am interested in walls as site-specific landforms created during the transition to the Anthropocene (an era in which human action dominates all others). I have written about the history of stone walls and how they should be interpreted in the field and developed the Stone Wall Initiative to bring public attention to their importance in New England. I am now working with students and colleagues to develop a formal, interdisciplinary science of stone masonry that will help researchers understand and preserve stone masonry.
dens and roads
My brother-in-law, Lee, particularly enjoys the wall in his New Hampshire backyard for its aesthetic, historical, and literary atmosphere. Wild creatures living in the neighborhood depend on this place as a unique living space.
For lichens and mosses, the dry stones of the wall are surfaces where plants cannot compete. For plants, such walls are edges that divide patches of soil into sunny or shady, windy or windless, uphill or downhill, wet or dry zones. Stone walls offer small mammals porous spaces in which they can live their insidious lives. Predators use walls as hunting screens and travel corridors.
Just for fun, my brother-in-law installed a motion-activated infrared video camera on his backyard wall to see who was using the wall and how. He filmed a lynx on the summer solstice, June 21, 2023 (lynx rufus) and then uses it as an elevated path.
The more we researchers learn about the abandoned stone walls of New England, the more we realize that they transcend and transcend the narrow approaches of our scientific disciplines. These archaeological artifacts are so ubiquitous that they have become a geological landform, creating a new ecological habitat. These walls are also literary icons, historical sites, and spiritual prophecies, as Robert Frost realized when he wrote “The Mending Wall” on an old farm in Derry, New Hampshire.
But despite their importance, the stone walls of New England have never been technically described, classified, or given common terminology in a peer-reviewed journal. They seem to have fallen through the cracks of discipline.
My first step toward changing this situation was to write a mini-monograph on “Taxonomy and Nomenclature of the Stonefield in New England” for the journal Historical Archeology in 2023. His goal is to unify studies of these stone walls into an interdisciplinary science, following examples from other disciplines (most importantly, the 18th-century Linnaean taxonomy that biologists still use today). This approach works like this:
Identification and classification
Scientific understanding of the masonry walls of greater New England requires starting with a technical description based on field criteria rather than tradition or inference. There are many types of historic stone features, such as waste piles, stone piles, scatterings, benches, kilns, tombstones, pavers, terraces and more. The aim is to isolate the walls as a series of objects within this larger space.
For example, a definition might require that every wall be made of stone; consists of particles rather than a giant plate; continually; thin and long; and high enough. Without such clear criteria, one person’s wall becomes another’s long pile, one person’s waste pile becomes another’s sanctuary.
It’s a good thing that descriptions and classifications can be loose and flexible, as with musical genres, fashion styles, and disciplines in academia. These are typologies, dustbins, pigeonholes. But to make scientific sense of the world, researchers need to transform descriptions into precise definitions and use them in binary, rule-driven classifications. These are taxonomies.
Each field of science requires its own language. Chemists group elements with similar properties, such as halogens and noble gases. Biologists divide life forms into domains, kingdoms, phyla, and smaller groups that share common characteristics.
Terms in stone masonry include size, shape, composition, origin, and arrangement of stones; vertical and horizontal structures of layers, courses and terminations; and their topographic settings in the landscape.
Stone masonry classification begins with the stone field, which is the entire constellation of historical stone objects. From here we form a distinct class of stone walls, distinct from other rock assemblages such as concentrations and lines, as well as notable individual stones such as Plymouth Rock. We then divide classroom walls into five families (freestanding, lateral, supporting, surrounding, and blocking) using diagnostic criteria and divide them into types, subtypes, and variants within a new taxonomy.
What can stone walls tell us?
At this stage, my students, colleagues, and I are just beginning to match stone masonry science with LiDAR techniques at the village scale. Exciting spatial patterns emerge.
Different types of walls appear in predictable arrangements. For example, we often see well-constructed double walls near the cellar holes, simpler single walls further away, and heaps of waste beyond them. Such models provide an independent source of primary documentary evidence that researchers can use to interpret past cultural behavior beyond the written documents of history and the much smaller artifacts of excavation-based archaeology.
Such spatial patterns can also be used for ecological interpretations. For example, a bobcat is more likely to hunt along a normal single wall than other subspecies because it has the necessary stability and height to support the cat and enough free space for the prey to survive.
These structures (these high arid areas) are in some ways similar to the region’s wetlands; these are also landforms that farmers created or significantly altered as they settled the land in the 18th and 19th centuries. But since the 1990s, wetlands have had solid science, a solid legal framework, and excellent management protocols.
In my opinion, it’s time to do the same for the stone walls of New England. These dryland structures are so widespread, massive, and unique compared to other habitats that it’s time for naturalists to give them the respect they deserve.
This article is republished from The Conversation, an independent, nonprofit news organization providing facts and authoritative analysis to help you understand our complex world. Written by: Robert M. Thorson, University of Connecticut
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Robert M. Thorson created and coordinates the Stone Wall Initiative, an online resource about the historic stone walls of New England. He is an advocate for their preservation and management and is a frequent public speaker on this topic to land trusts, historical societies, environmental nonprofits, public libraries, and “friends of…” organizations.