at sea, is a hole in the ship, through which the water comes in. A ship is said to spring a leak when she begins to leak or to let in the water. The manner of stopping a leak is to put into it a plug wrapped in oakum and well tarred, or in a tarpawling clout, which keeps out the water, or nailing a piece of sheet lead on the place. Seamen sometimes stop a leak by thrusting a piece of salt beef into it. The sea-water, says Mr Boyle, being freer than the brine imbibed by the beef, penetrates into its body, and causes it to swell so as to bear strongly against the edges of the broken plank, and thereby stops the influx of the water.—A ready way to find a leak in a ship is to apply the narrower end of a speaking trumpet to the ear, and the other to the side of the ship where the leak is supposed to be; then the noise of the water issuing in at the leak will be heard distinctly, whereby it may be discovered.