Caisson 1 : (1) A sunk panel in a coffered dome or ceiling. (2) An engineering cylindrical steel structure for lowering into the bed of a stream so as to obtain a firm foundation for the piers of a bridge
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}