University of Connecticut University of UC Title Fallback Connecticut

Author Archives: Thorson Robert

Landscape Design with Stone Walls

It’s nice to know that stone walls are increasingly being retained within subdivision designs, rather than obliterated as being in the way.  In this quick post, I relay (with permission) a particularly eloquent paragraph by Randall Arendt, from a chapter titled “Protecting Natural and Historic Resources through Conservation Design” within his 2009 book Envisioning Better Communities.  I have boldfaced words and phrases that are particularly critical to the mission of the Stone Wall Initiative.

A wide variety of site features involve historical uses, including farmhouses, barns, country lanes, stone walls, wells, cellarholes, hedgerows, etc. Incorporating them into site design can add significant interest value to the neighborhood, improving marketing possibilities and enhancing the quality of life of residents in the development and the surrounding community. From long experience, I can say that designing around stone walls and hedgerows (or fencerows) is not difficult to do when one is given flexibility in lot size, lot width, and street geometry. All too often these features are blithely ignored by site planners who either have not walked the property to locate them, or who demonstrate no care or reverence for these artifacts from earlier eras. (Quoting Daniel Webster: “The man who feels no sentiment or veneration for the memory of his forefathers is himself unworthy of kindred regard or remembrance.”) To the extent that these value-adding aspects of the property are not retained, when it is relatively easy to do so, site designers are not serving either their clients or the community very well…

The pair of his drawings above show: to the left, a subdivision layout conserving and highlighting the historic features; and to the right, a traditional layout where lot size is maximized at the expense of the historic landscape.  Which would you rather live in?

For more information, visit Arendt’s website Greener Prospects.

Saving Historic Mill Walls

The SWI extends its congratulations to the Historical Society of Glastonbury, CT for raising funds to save and restore the stone walls of Hopewell Mills, located on Roaring Brook.  For the full story, consult the July 6 story in the Hartford Courant.

Such mills are testimony to the adaptability and innovation of America’s energy use.  Fully ten percent of America’s energy now comes from renewables, ethanol are on the wane, nuclear is being re-thought, fossil fuels are slowly being phased out, and hydropower has fallen into the shadows.  Building them required stone, and lots of it. Hence, stone walls played an critical role in America’s energy policy, especially in the decades prior to the Civil War.

However, there was a time in American history when hydropower was king, and when manufacturing was totally dependent on it.  Largest was in Lowell, Massachusetts where “the controlled flow of water turned 31 mills, 6,300 looms, and 225,000 thread spindles” in a city created at a hydropower site on the Merrimack River.*  Even there, in the rush to embrace coal, those plants turned to steam and let the water go by.  Eventually most of these mills closed as America’s energy policy moved towards coal, and then petroleum, and now gas.

Such mills nucleated communities all across America, concentrating people, especially recent immigrant workers, in ways that would not be repeated again.

*Quote from my recent book, The Boatman (Cambridge, MA: Harvard Press, 2014), 214. This sources Theodore Steinberg’s Nature Incorporated: Industrialization and the Waters of New England (New York: Cambridge University Press, 1991).

The photo above is from Maynard, MA.

Town of Goshen Connecticut Conserves its Highway Walls

The town of Goshen, CT has created an model ordinance for the conservation of stone walls along town highways.  Having recognized them as essential “agrarian landmarks,” and a vital part of town scenery, they have passed this regulation.

Link to Regulating Roadside Walls in Goshen, CT.

The town website is

Their work was done to minimize the loss of stone walls via:

  • Homeowners interested in tearing them down, possibly with the intent to sell the stone
  • Over-reach by road improvements, and
  • Piecemeal removal of stones from scavenging (poaching) by non-owners.

One key definition in the ordinance is that the “highway boundary” is the centerline of the stone wall flanking it. Walls can be removed and changed with a permit.  Another is that the default action is to leave the walls as they are, rather than the default action being to allow individual landowner to do whatever they like with them. This is a fundamental issue of private property rights versus community rights.

Photo:  Not in Goshen.  Roadside stone wall on a town highway in Mansfield, CT is being preserved, even though it is only a historic remnant and logging would be easier without it.  

Stone piles? Agricultural or Something Else?


I’m frequently asked if a stone pile is associated with Native American tradition, or an artifact of agricultural activity. Having been recently asked this by someone with the administrative responsibility of adjudicating this debate, I thought I’d put it in my SWI blog, and make it available to anyone interested.

First, the presence of Native horticulture turns this binary (Native vs. agricultural) into a tautology.   More simply, a pile can be Native AND agricultural at the same time. Cobble piles in Native farming sites should look like those of Euro-Americans.

Second, the binary of farming vs. Native American  is only one set of explanations that is logically equivalent to the set of other explanations we do know about, which is logically equivalent to the set of explanations wee do not know about. A decision about one pile must be made in the context of these three sets.

This begs the question: “What’s a stone pile?” First, it’s an unconsolidated (loose) concentration (many stones) of clast-supported (stones rest upon one another without being supported by matrix) eminence (positive topographic feature). To me, “pile” connotes a “dumped” degree of order, meaning the mass of stones are not deliberately stacked or arranged in any particular way. This leaves the possibility of surface alteration/decoration/shaping possible without disqualifying it as a pile. Depending on context, a stone pile may be no more than a few stones placed one upon the other. Or it might be a giant heap. I’m not going to define it here because you probably have a good working definition in mind. And that’s good enough for now.

The much easier question ignores these sets of possibilities and deals with one straightforward question: Is this an agricultural pile? If we turn this question into a statement that is relevant, ethical, original, and can which will yield a yes/no result is a hypothesis. By relevant I mean is it worth spending personal or societal effort on it. By ethical, I mean that it does not transcend our community standards of behavior toward one another. By original, I mean it hasn’t been done before: each new pile is an original question. By a yes/no result I mean it is one or the other. Anything fuzzier result disqualifies the statement as being a hypothesis.

Depending on circumstances, the question “Is it an agricultural pile” can be tested within certain limitations in the New England woodlands.



 The most important and useful limitation is the assumption of “utility and expedience” in the context of making a living from the land with Euro-American agriculture practices involving mixed husbandry: pasture/ tillage/ sugar-bush/ woodlot etc. during what I call the “pioneering” and “established farm stage.” Humans have limited agro-ecological resources and do not do things like building piles either frivolously or “just for the heck of it,” which I call the idiosyncratic function.

Making the utility-expedience assumption requires that stones were piled to dispose of a local excess of stone, and that local excess was not needed to serve as a source of stone elsewhere. If this were the case, and if the stones were uniformly distributed, then so too should be the piles. Furthermore, the spacing and mass of the piles should correlate with the stoniness of the land.

Outcrops, slabs of rock, residual stumps, ravines, swamps, fence-lines, are sites where neither pasture grass nor crops can grow. Hence, they are preempted from productive activity. They will absorb waste stone if they are close enough to the source. In fact, sprawling stone piles on slabs of rock and outcrops are diagnostic of agricultural waste disposal, and will be used before piles are built on non-preempted land.

Utility-expedience requires that the stone in a pile is not carefully places. It can be placed to economize space, but will not carefully so.

Piles grow outward like talus cones. Along any ray, they are concentric. Any variation in the stone coming at the pile will manifest as “vertical” stratigraphy. A dumped load(s) is suggested by a more massive texture (with exceptions). Dumping, however, usually imparts an asymmetry in plan (like a fan) and cross-section (like a snow-drift with the steep side nearest the site of dumping).



An independent test involves comparing the spatial pattern and morphology of known agricultural piles to those of unknowns. The simplest association here is that waste piles are usually plural, and seldom singular. Let’s not forget that waste piles were harvested to create stone walls. Hence, it’s hard to assume that the resulting pattern is the whole original pattern.



When presented with two explanations for one phenomenon, the most likely to be correct (not the same as being correct) explanation is the simplest one. What this means is that a stone pile in the woodlands can be assumed to be an agricultural pile unless proven otherwise, because this is the simplest explanation.




Learn How to Build Stone Walls

Stone Wall Workshop
Saturday, May 21st, 9:30 am-12:30 pm, Adults $40
Prescott Farm, 2009 West Main Road, Middletown, RI, 02842
Master instructors Chris and Dan Smith have helped students build and repair miles of traditional stone walls in this popular workshop. Great for owners of historic properties in New England who have stone walls on their land, or for anyone interested in the history and craft of stone walls. Advance reservations required. 
Feel free to get in touch for any thoughts or questions: 401-954-0361

Massive, Massive Wall

Rockefeller wall behind Coach Barn, Pocantico Center, Tarrytown, NY. Photo by John Phillips, April 2016

Rockefeller wall behind Coach Barn, Pocantico Center, Tarrytown, NY. Photo by John Phillips, April 2016

Amazing. One minute and I was inside the lovely conference center in the Coach Barn on the Rockefeller Estate in Tarrytown, Westchester County NY. The next minute I was out the back door standing below a wall at least 30 feet high and built of massive boulders plucked from nearby fields.  With me was a group of architects, educators, artists, and staff of the Pocantico Center, which arranges tours of grounds of this property, now managed by the National Trust for Historic Preservation.  The questions kept on coming.  Why so tall?  Where are the boulders from?  Why do they let the ferns grow through them?  And above all – How come it doesn’t fall down?

I made up the answers on the the fly just by looking at what I could see.  To the right was a “battered” wall of dimension stone, which means it was cut straight from the quarry to the proper dimensions. And yes, the  word battered is correct, for that’s the word for the angle away from vertical that the wall is laid for ideal support.  To the left was a massive arch, also built of dimension stone, through which the horses and carriages used to enter what had been the finest barn I’ve ever seen: an enormous structure built of quarried gneiss.  Between these two masses of quarried stone was inserted the wall you see.  Some of the boulders were a yard in diameter with nary a scratch mark on them.  Indeed they were “milled” within the shear zone at the bottom of the ice sheet that spread them over the land before melting down to a last gasp.  The placement was the ideal mix of random and deliberate, with no real “courses,” as with a brick wall, and no more than one “tier” meaning only one group of stones from bottom to top, at least in this view.

It’s such fun so share something so fun. With just a few words for stone size, shape, composition, and surface texture, the tour group began to sound like experts.  They were now empowered to go “Exploring Stone Walls,” the title of one of my books.

Are Walls Landforms?

Z BlockIsArchytype

Block Island Wall: Is this a landform? That depends

To answer the question of whether stone walls are landforms, I like to start with the word “landscape.”  According to Webster’s this 16th century word derives from the Dutch landschap, meaning “land + ship.” Tracking back through the etymology of the Oxford English Dictionary, however, indicates that the concept clearly predates the 5th century A.D.

Being empirical, ignoring the conventions of art history, and based on the way I hear the term used colloquially and professionally, a landscape is not a place, but an image (visual or mental) of a place that consists of physical entities and that can be seen and appreciated by the human eye from a single spot, often by a single glance.  Technically, its the cone of human vision at the familar scale of village, coast, or rural geography.  A human presence is always either present or suggested.

In contrast, a landform is easy to define because  no cultural connotation is required. Nor is there a required scale. To geologists like me, a landform is any natural discrete physical object composed of “land” (rock or earth) that can be observed in its entirety.  Because humans were visual primates long before they became stone-age men and women, the form of the landscape (landform) has held higher priority over the equally important elements of the material they consist of, the process creating them, and the time involved.

Typically, a landscape is younger and larger than the set of landforms within the scene.  The only exception to this commonality is when the natural scene contains little or no topographic or lithologic variety, for example a sand plain as smooth as a glassy sea such as the the Llano Estacado of west Texas.

So are New England stone walls landforms? It think yes, even though I included the term “natural” in my definition.  First, the vast majority of walls are no more complex than many natural forms, a star-dune for example, or the herringbone structure on a fine-sand beach.  To exclude them as landforms because they were built by humans is to suggest that humans are not natural.  I refuse to accept this false, and damaging dichotomy.






Learning to Build a Stone Wall


Tarnished wood and stone on an ancient building at the Eric Sloane Museum in Kent, Connecticut.

In political dialogue, the infinitive “to stonewall” means to delay or prevent something by putting up a serious barrier of some sort.  Not so for those of us who appreciate the fine art of building a stone wall from scratch, given a supply of stones.   Fortunately, there are a growing number of workshops that individuals can sign up for to learn the art, or practice, of dry stone masonry.

For most people, this is a ritual way of entering New England’s former stone age, generally spanning the 18th and 19th centuries.  For me, it’s like playing outdoor chess. Indeed, some pieces are more valuable than others, strategy is important, and pawns are often sacrificed en route to victory.  And all of this takes place aerobically outdoors.

Last week I was at the Eric Sloane Museum in Kent, Connecticut to spend a day in celebration of New England’s historic stone walls.  This event overlapped with one such stone wall workshop, hosted by the “friends” group of the museum taught by Carl Dill.  The previous week, I recall reading about one at Parmelee Farm in Killingworth, taught by Andrew Pighills and Dan Snow.   And this week I learned of one being offered in Portsmouth, New Hampshire, sponsored by the Wentworth Gardner and Tobias Lear Historic Houses.  With news of three such events reaching the Stone Wall Initiative in as many weeks, I decided to write a blog posting alerting readers about the phenomenon in general, and Portsmouth’s 2 day intensive hands-on masonry conservation class in particular.  It will run on June 13 & 14. The contact person is Sandie Dika, who can be reached at 603-426-9282.

Are Their Pre-Colonial Stone Ruins ?

Sampson's Rock in Madison is a special place, named after the biblical strong man. This is a glacial erratic, a "rocking stone" and, in this taxonomy, a Notable Stone.

Sampson Rock in Madison, CT is a special and evocative place This is a glacial erratic, a “rocking stone” and, in this taxonomy, a Notable Stone.

Of course there are!  There have to be!  Hundreds of thousands of human beings have walked and worked the New England uplands for at least 11,000 years.  And many features have been confirmed as pre-Colonial by properly credentialed archaeologists.

But let us not conflate the few, the small, and the odd stone features in the woods with the latticework of abandoned stone walls gracing much of the New England countryside. This latticework of walls is the collective work of colonial and early American farmsteads built by Euro-settlers and their descendants since 1607.

Last night, while giving a talk to the Boxborough Conservation Trust in Massachusetts, I got the inevitable question about pre-colonial stone ruins.  This morning, I decided to post my answer in the form of a keynote speech I gave several  years ago to the New England Antiquities Research Association.

Follow this link.


Stone Pile Steaming Away


Friday, February 20, 2015  was a bitterly cold night in New England.  At the University of Connecticut where the SWI is based, the overnight low was -15 F.   The following morning, stone wall enthusiast Kate Johnson sent me a video-clip taken by her parents, Claire and Steve Johnson, from Little Compton, RI.  It showed steam rising from a stone pile like smoke from a dying campfire.  Thinking other stone wall enthusiasts might be interested, I decided to post it on the SWI website.  Click on this link to see it.


To understand this, let’s start with the simpler case of steam rising from a patch of open water on a frozen pond or a stream.  Under calm, but not cold atmospheric conditions, the extra moisture above the liquid water is invisible because it’s water vapor, a clear gas.   But when the ambient temperature becomes very cold, the air above the patch is much less dense and moist than elsewhere.  So it rises, cools, and condenses into a fine mist.  These tiny droplets then migrate away, evaporate in the cold dry air, and become invisible once again. Something similar happens above chimneys, drier vents, and volcanoes.
Now imagine a deep fluffy snow on a forested New England soil.  The insulation of the snow adds to the insulation of the forest mulch, to prevent or restrict the depth of frozen ground.  In this situation, the air within the unfrozen soil –driven by gradients of temperature and vapor pressure–migrates upward to the base of the snowback, condenses, and is frozen before it can be seen.
When the snowpack is crusted with ice, however, this upward escape of soil air is blocked.  And when  frozen ground is deepening, or when the water table is rising, the soil air is squeezed sideways toward a place of escape. Old stone piles and tumbled stone walls provide these avenues, becoming  vents for warm moist air. The extra cold of the stones (caused by more rapid conduction of heat) may help speed up this process.
As with a patch of open water on a frozen pond, the patch of warmer-moister air beneath a stone pile rises,  cools, condenses, and evaporates, producing a ghostly transient mist.  The careful observer of nature gets chance to see native fieldstone steaming away.
Thanks Claire and Steve for catching this process in the act. Spread the word. Share the stone joy.