Alden works out a dry-stone wall the way a waller does, and then tells you what is wrong β with it. Give it the wall you mean to build π¨ β the type β¨οΈ, how high and how long, the ground it sits on, whether it retains anything, the coping you want and the rock you have β and the whole cross-section is drawn to scale: the base width taken from the batter rule, the courses tapering in lift by lift, the coping row on top. Over that section runs the thrust line, and the middle third of the wall is shaded behind it, because a wall stands while the thrust stays inside that band and begins to open at the back when it does not. The three factors of safety against overturning, sliding and bearing are computed and printed against their thresholds, and nine classic ways a dyke fails are checked against your design, so a wall too steep, too thin at the base or too poorly tied through is named as such before you lift a stone. What comes out is a working order: how many throughstones and at what spacing, the hearting volume, the cope count, and the tonnage per metre broken down by stone class β in tonnes or imperial, rounded the way you actually buy it.
What you can do: keep several dykes in the yard and compare βοΈ them, read the eight rock types, seven stone classes and ten walling tools π οΈ in the reference, photograph the stones in your own heap and tag them into a board that measures what you have against what the wall needs, and file the finished stone order to your photo πΈ library π as one strip you can take to the quarry.
Design a dry-stone dyke and see π whether it stands.