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Community landmark

Solar Alignment Feature, Amherst Island

A sinking pillar on a community landmark, dismantled to diagnose a bedrock shelf nobody had encountered, then rebuilt on solid foundation.

Two large limestone blocks being set side by side on a course, a gloved hand at either end of the frame and the packed hearting visible in the joint between them.
Solar Alignment Feature, Amherst IslandMadoc limestone replaced course by course, 2024
Site
Solar Alignment Feature, Amherst Island
Location
Loyalist Township, Ontario
Client
Loyalist Township
Year
2024
Stone
Quarried dolomitic limestone, Madoc, Ontario
Scope
One pillar — dismantle to foundation and rebuild
All projects

The site

A solar alignment feature, built by hand in 2015

In 2015, Dry Stone Canada held a festival on Amherst Island. The showcase feature is an arrangement of walls built to align with the sunset: a wall pierced by a Celtic cross through which, twice a year, the sun’s rays fall onto a receiving wall and the carved marker set in it. Four pillars stand between these two walls, two on either side of the beam, each holding a bench cantilevered into the stonework.

The land belongs to Loyalist Township, but the site belongs to the community. Islanders and visitors use it year-round, making it necessary to address the south-west pillar, which had begun to shift.

The solar alignment feature was built by professional wallers as part of a community demonstration of dry stone principles. During the event, four complementary pillars were built simultaneously on ground excavated to a uniform depth. When one of the pillars showed signs of subsidence, there were several theories as to the cause. Only once the structure was dismantled could we establish the cause of the slippage and ensure that the rebuilt structure would be secure.

Four of the crew standing and talking on the grass at the solar alignment site, a dry stone wall at the left of the frame, a pillar at the right and the lake behind them.
The site, looking out to the lake

Analysis

One pillar was sinking, and nobody knew why

An excavation was undertaken to investigate the subsidence. The site was excavated to bedrock and a shelf was discovered under the gravel and clay. The pillar’s foundation spanned this shelf, meaning the north side of the pillar was built over a shifting base while the south side of the pillar was over solid ground.

  • A waller in a hi-vis vest lifting a stone clear of the part-dismantled pillar, a barn and grain silo in the field behind him.
    Taking the pillar down
  • Two of the crew digging out the ground beneath the dismantled pillar with a long-handled spade, a wheelbarrow of excavated material beside them.
    Excavating the old foundation
  • A gloved hand holding a steel tape measure upright in the open excavation, the blade running down past loose stone to the bottom of the hole.
    Measuring down to bedrock

The record

Measured coming down, measured going back up

The pillar
MeasureImperialMetric
Height, including copes79 in2.01 m
Height, below copes68 in1.73 m
Width at base50 × 39 in1.27 × 0.99 m
Width at top, below copes41 × 18 in1.04 × 0.46 m
The new foundation
MeasureImperialMetric
Excavated to bedrock12 in0.30 m
Solid stone laid on the bedrock8 in0.20 m
Foundation course tops out below grade4 in0.10 m

The base was rebuilt with larger stones to address the shelf in the bedrock. Fewer, but larger, stones were set as the base. As the pillar was rebuilt, the stones forming the four faces were installed where they had been originally. The cavity in each course, previously filled with stone shards as hearting, was altered through the use of larger blocks of remnants of Madoc stone, stockpiled after the original event.

Method

Rebuilt on rock, course by course

The gravel and clay were taken out until the whole footprint stood on bedrock. Large stones were set directly on the rock to level the footing and give the pillar solid bearing across its full base, and it went back up course by course — larger stones low, the cantilevered seat set deeper into the structure than it had been before.

The pillar looks as it did. What changed is underneath it.

  • A timber batter frame standing over the cleared pillar footprint in low evening light, the dismantled stone laid out in rows on the grass and two of the standing pillars behind it.
    The batter frame, set to the pillar’s own taper
  • A large flat foundation stone rigged with chains beneath the bucket of a compact tractor, on the grass beside the open excavation.
    Foundation stone brought to the hole
  • Three of the crew crouched at the pillar footprint, running a long steel straightedge across the newly set foundation stones.
    Levelling the new footing

Material

Stone from Madoc, Ontario

The pillars were built and repaired with quarried dolomitic limestone from Madoc, Ontario. For the alignment feature, sharp lines and edges were required to achieve the full impact of the light from the setting sun. Dolomitic limestone lends itself to shaping with tools, and the professional dry stone wallers volunteering on the project cut each stone to get the best face — and the best fit — possible.

Island stone had been considered and ruled out for the feature. It is a scarce resource on Amherst Island. Gathering stone from roadside walls, or “fences” as they are known on the island, is discouraged because of their cultural value, and removing stone is restricted outright in the island’s protected habitat areas.

However, islanders contributed to other features built at the 2015 event, by bringing stone retrieved from their own properties. People donated bedrock, blasted for the creation of foundations or septic beds, and granite erratics, the kind collected by farmers for generations. The rustic look of the island stone on a wall adjacent to the solar alignment feature highlights the different qualities of these natural materials.

Stone from the dismantled pillar laid out in rows on the grass, kept in order, with the coursed face of one of the standing pillars at the right of the frame.
Madoc limestone from the 2015 build, laid out to go back

Crew

Who was on site

Four wallers and site support, working for Loyalist Township in September 2024.

Menno Braam
Site lead
Scott Young
Waller
Andrew Pritchard
Waller
Lief Roebuck
Waller
Jacqueline Jeffers
Site support
Four wallers standing at the finished pillar, one hand resting on its capstone, the coursing and the taper of the rebuilt structure running down to the grass.
The rebuilt pillar, September 2024

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