Fig. 1, Showing lines of Fracture in Cast Iron Ordnance subjected to Explosive Strains; Figs. 2, 3, Illustrating the fact that Rupture takes place first in the Interior of the Gun, the Fragments folding over on the Points A, B, C; Figs. 4, 5, Showing the Spongy character of Cast Iron in Cruciform Castings; Figs. 6, 7, 8, 10, Showing lines of Crystallisation, illustrating the Law of “Least Resistance;” Figs. 14, 9 B, Showing weakness of Square Breech, Fig. 14, representing Portion of the Lower or Closed End of Cylinder of the Hydraulic Press as first made for Raising the tubes of the Britannia Bridge, and which broke in the attempt, the end of the Cylinder having broken out as in Fig. 9 B; Fig. 9 representing section of part of the new Cylinder substituted for the faulty one, Fig. 14; Fig. 11, Showing section of Reinforce Ring in Plane of the Axis; Figs. 12, 13, Sections of portions of Large Cast-iron Guns, showing the weakness of Cast-iron Trunnions, v, v. Indicate Directions of Weakness.