1868.] Gilbert's Patent Iron Ceiling. 65 Fig. 10. Cells for jails or other pur- poses, for which these corrugated iron- arched plates are particularly adapted. The cut shows two cells, a single and double arch; the upper cell showing the single arch resting on the walls of the cells, and lower cell the double arch, using the iron beam. Fig. 11. Fig. 11 illustrates the different styles of castings or socket-bearers on which the ends of the corrugated iron plates rest. Fig. 12. Wrought-iron beams used in the construction of fire-proof buildings. Fig. 13. A wrought-iron (I) beam, with socket-bearer resting on the lower flange thereof, on which rest the ends of the corrugated iron plates which arc riveted thereto, forming an abutment of great strength and solidity, and giving a very complete and substantial finish. Fig. 12. Mr. Fairbairn, Civil Engineer, says : "Assuming wrought-iron plates one- fourth of an inch thick, and bent in the Fig. 13. segmental form of an arch, with the filling up of the haunches with concrete
