From the following list, which gives the average breaking stresses in tons per square * inch, the relative strengths of cast iron, cast steel, gun-metal, and brass may be obtained. In tension: Cast crucible steel, 45 tons; mild steel, 35 tons; steel for castings, 30 tons; gun-metal, 12 tons; brass, 11 tons; and cast iron, 7 1/2 tons. In compression: Cast crucible steel, 80 tons; cast-iron, 15 tons; gun-metal, about 12 tons; and brass, about 11 tons. In shear: Cast crucible steel, about 30 tons; steel for castings, about 20 tons; gnu-metal, about 8 tons; and cast iron, about 5 tons. The safe stresses for live loads are as follows. In tension: Cast crucible steel, 8 tons; steel for castings, 5 tons; gun-metal, 2 tons; brass, 1 1/2 tons; and cast-iron, 1 1/4 tons. In compression: Cast crucible steel, 8 tons; steel for castings, 5 tons; gun-metal, 2 tons; brass, 1 1/2 tons; and cast iron, i tons. In shear: Cast crucible steel, 5 tons; steel for castings, 3 1/2. tons; gun-metal, 1 1/2 tons; brass, 1 ton; and cast iron, 1 ton.