At the North Flume discharge point, Jo Saye’s first experimental sleeve was being subjected to the ultimate water-pressure trial. The eight-foot metal tube of double-layered reed canvas had swelled to its total sharp-angled limit, swelling into a rigid, groaning tube three feet across that shook with a nonstop, high-pitched hum like a cello string tuned two octaves too high.
Water was sweating through the tight weave of the bleached linen outer layer in thousands of fine, needle-like jets that formed a dense white mist around the platform. Down the belly of the sleeve, the single line of red running stitches that marked the intentional failure seam was stretched taut as an iron wire, the flax threads turning dark as they absorbed the boiling stone salts from the discharge.
A young local apprentice named Rob, who had spent his life repairing wooden water gate gates, was standing near the timber frame with an iron-banded timber clamp in his arms. “Mistress Saye!” Rob shouted in panic. “The red thread is singing! The belly is going to blow! Let me throw this iron clamp across the seam before it bursts!”
“Don’t touch that canvas, lad!” Jo Saye commanded, her voice cutting through the roar of the water with the total, uncompromising power of a master craftswoman. “Step back behind the timber frame this instant!” She caught the boy’s collar with her leather-mittened hand. She dragged him five paces back onto the dry staging deck. “That seam is singing because it’s designed to sing…
