Note 2 — THE RIVAL CRUSOES;
Reading edition
The well is an apartment in a ship's hold, serving to enclose the pumps. It is sounded by dropping a measured iron rod down into it by a long line; hence the increase or diminution of the leaks is easily discovered.
"They sound the well, and, terrible to hear, Five feet immersed along the line appear; At either pump they ply the clanking brake, And turn by turn the ungrateful office take."
Falconer's Shipwreck.