Barry wavy

A field parted across into an even number of stripes is barry, and when the lines that part it wave, barry wavy. William St John Hope puts both in one breath: “an even number of bars became barry. Undulated or waved bars formed wavy, and sometimes paly and pily stripes were also waved”. Here the field is argent and azure, in six pieces. We know of no period rule for drawing the wavy line, so the construction here is our own, and it is exact. Each wave is a chain of arcs of one opening, every arc a third of a circle, swung by turns about a pin below a crest and a pin above a trough. Neighbouring pins stand two openings apart, so where one arc ends the next begins in the same direction, without a kink. Every pin lies on one net of equilateral triangles. A chain of circles steps down the middle of the shield; neighbouring circles cross to either side, and lines laid at thirty degrees from the steps through those crossings cross one another at every pin of every wave. The line through the first two crossings cuts the middle half a step down, which is the opening of the arcs. The shield stands on the same net: its feet where swings of three steps meet, its flanks swung at the width from the opposite feet, its point on the last step. The waves stand one step apart.