Ballast

any weight carried in the hold of a ship to keep it right side up. It is necessary, especially in the case of a sailing ship, to load the hold heavily, or the immense expanse of canvas spread to the wind may cause the ship to tip over. In the case of an empty ship going after cargo, or departing from port with a light load, sailors take on board any heavy material, as bags of sand, gravel, stones, or earth. The best of all ballast is, of course, bars of iron, or better yet, lead, that lie low and occupy little space. Harbor rules enforced by the authorities of the various ports prescribe the places where the ballast of incoming ships may be thrown overboard, so as not to obstruct the channel. Very frequently it is piled up on the shore, so as to be available for the next ship that needs it. Steam vessels showing little canvas require less ballast. Most modern ships use water, which is pumped into or out of tanks arranged for the purpose. In the case of war ships with a heavy weight of guns on deck, heavy ballasting of lead is run into the lowest part of the hold to balance the metal above. The term is also applied to the bags of sand carried in balloon ascensions, and to the earth packed between the sleepers on a railroad track. An unstable person is said to lack ballast.