Sluice-Wardens of the Millrace Undershot — an age when a fenland grain-town channels its whole river through one narrow stone millrace beneath the great wheel, a chute so tightly built that the entire spring melt is forced into a single throat of white water, and the Sluice-Warden is the one appointed to stand planted on the slick sill-board that spans the race at its narrowest point, ankle-deep in the shoulder of the flow, not to raise the paddle-gate and not to drop it, only to REMAIN on the sill through the whole thundering run so the millers below can read the true head of water off the set of her body — she is the living gauge, and every ton of river that hammers through the throat wants to buckle her knees and fold her downstream into the wheel-pit