Reading the fallen wall before touching it
The first weekend I owned a fallen wall I did not lift a single stone, and I am glad of it. Instead I walked the forty metres with a tape, a notebook and a camera, trying to work out how the wall had been built before I presumed to rebuild it. Dry-stone walls are regional; the style of coursing, the batter, the way the copes are set all vary from one valley to the next, and a rebuilt stretch in a different style looks wrong forever.
The standing half gave me most of the answers. It is a random wall rather than a strictly coursed one: the stones are of mixed sizes and the courses wander, but each stone still sits across the joint below it. The surviving section stands 1.15 metres to the top of the copes, is 720 millimetres across at the base and narrows to about 400 under the copes, which gave me the batter to copy. The copes are set upright and lean slightly uphill. The throughs are visible on both faces as a line of slightly protruding stones at a little over half height, roughly a metre apart.
The fallen half told a different story. I pulled the grass back along the whole length and found the throughs lying where they had slid, which helped me count how many I would need. Where the collapse was worst, a sycamore had grown up through the base and lifted the footings on one side; where it was least bad, the wall had just slumped as the hearting washed out. I marked each change of condition with a peg and a note, and photographed every metre with a numbered card in the frame.
Measuring the fallen stone was a rough business. I paced the hump, estimated its cross-section and came to perhaps three tonnes lying in the grass, which turned out to be an underestimate by about a third once it was all sorted. Even so, I knew by the end of the weekend that I would need another tonne or so of matching stone for the worst stretch, and that is what I ordered later, rather than guessing at the start.
The notebook from that weekend has become the plan for everything since: the heights, the widths, the number of throughs per metre, the direction the copes lean, and a sketch of the one standing stretch that I think the original builder would have been proud of. Two days of looking before two years of lifting. I would do it again.