Steel embrasure for the fortifications of Cronstadt, manufactured at Millwall, 1864. A ...three-gun wrought-iron shield...[made] by the Millwall Ironworks Company for the Russian Government...The shield is 43 ft. 6 in. long and 10 ft. high...The total weight is about 140 tons, and it is proposed to erect the structure...as a substitute for the stone parapet...which at present stands on the ramparts, while the guns...will be replaced by 600-pounder steel Krupp guns mounted at the embrasures, in which elevated position they will be able to sweep the decks of any opposing force of ironclads. The relative power of resistance to the impact of shot between granite and iron is here distinctly illustrated, the proportions being as nearly as possible inches in the case of the latter to feet in the instance of the former. if this experiment in iron fortification...succeeds, the revolution in the system of the defence of fortresses and forts will have practically begun. Mr. Hughes, of the Millwall Ironworks, is one of the patentees...and Mr. Lancaster, the well-known artillerist, is the other. An important feature...is the facility with which any portion of these iron fortifications can be replaced if injured, or the whole removed if desired. From "Illustrated London News", 1864.