The subject line stuffing box got me intrigued.

As a boater, the "stuffing box" that I know is the area along a propeller shaft that lets it extend from the engine, inside the hull, to the propeller outside in the water. Since that shaft goes through a below-the-water-line hole in the hull, you need to prevent water from leaking through that same passageway and sinking the boat.

The stuffing box originally was a tar-soaked rope wound around the shaft and squeezed so that it was tight around the shaft, compressed by a nut -- it allowed just a slight drip of water (that can be coped with by an occasional use of a pump) to barely lubricate the shaft and prevent the rope from getting too hot. Nowadays, they use all sorts of different materials, and even different contraptions that prevent a leak altogether.