The pavement or surface on or over which fuel is burned in apartments. But the term hearth, in naval affairs, implies, the grate and apparatus employed on board ship for preparing the food or messes for the ship's company. It is fixed upon deck, in a small covered building, fitted up with a variety of conveniences for the cook and his operations. The modern apparatus usually comprises a steam boiler, coppers, ovens, hot closets, in addition to a large open fire.