SAFETY n.
opens automatically to permit the escape of steam, or confined gas, water, etc., from a boiler, or other vessel, when the pressure becomes too great for safety; also, sometimes, a similar valve opening inward to admit air to a vessel in which the pressure is less than that of the atmosphere, to prevent collapse.…
SHELL n.
llfish, or testaceous mollusks. Fuller. -- Shell mound. See under Mound. -- Shell of a boiler, the exterior of a steam boiler, forming a case to contain the water and steam, often inclosing also flues and the furnace; the barrel of a cylindrical, or locomotive, boiler. -- Shell road, a road of which the surface or b…
STOKEHOLD n.
The space, or any of the spaces, in front of the boilers of a ship, from which the furnaces are fed; the stokehole of a ship; also, a room containing a ship's boilers; as, forced draft with closed stokehold; -- called also, in American ships, fireroom.