There is a moment in the assembly of a very expensive watch that no customer will ever witness, and that is rather the point of it. Anglage is the craft of bevelling the edges of a movement's components. A watchmaker takes a steel lever or a brass bridge, files a chamfer along its border at roughly 45 degrees, then polishes that narrow ribbon with wood and diamond paste until it throws light like a filament. On a good movement this takes hours. On a great one it takes days. And a meaningful portion of that work is performed on the...