The Clew
The clew is the lower aft corner of a fore-and-aft sail — the point where the sheet attaches. Every adjustment the helmsman makes to the sail angle passes through the clew: haul the sheet and the clew moves inboard, tightening the sail; ease the sheet and the clew swings outboard, letting the sail open to the wind. Above the clew, yards of sailcloth catch the air. Forward of it, the luff holds the sail's leading edge to the mast or stay. But the clew is the corner that is controlled, and through it the entire sail is controlled. One corner, one line, and the sail does what the helmsman asks.
On a square-rigged ship, each sail has two clews — the lower corners — and the clewlines are the ropes that haul those corners up to the yard when the sail is to be furled. Buntlines gather the belly of the sail. But the clews come last: they are the lowest points, the farthest from the yard, the parts still catching wind after the rest of the sail is already bundled. Pulling the clewlines collapses the sail from its working shape into a mass of canvas that the crew can then climb the rigging to secure with gaskets. The clew is the last point to leave the wind and the first point set when the sail is dropped for use. It is where the sail begins and where it ends.
The word clew meant a ball of thread before it meant a sail corner — from the ball of yarn Ariadne gave Theseus to find his way out of the Minotaur's labyrinth. A clew was something wound up, gathered at a point. The sail corner is called a clew because the sheet gathers there: the whole force of the wind on the sail concentrates into the hardware at that corner, where grommets, rings, and thimbles collect the canvas into a single attachment point. The modern word clue — evidence that leads to an answer — descends from the same thread. A clue is a line you follow. A clew is where the lines collect.
Three clews: a sail corner, a furling point, a ball of thread. Each gathers something larger into something small enough to hold. The wind in the sail, the canvas on the yard, the path through the labyrinth — all are managed through a single point where the distributed becomes concentrated. The clew is not the sail, the rigging, or the maze. It is the place where control becomes possible because everything converges there.