MATERIALS By McKay Period: 1840 to 1900 CAST IRON Period: 1840 to 2019 TIMBER 1850 BLOCK D Period: 1850 to 1920 WROUGHT IRON 1860 BLOCK A1 TIMBER, CAST IRON, MASONRY 1890 BLOCK A2 Period: 1890 to 2019 STEEL Period: 1900 to 2019 MODERN CONCRETE 1910 BLOCK B 1920 BLOCK C 2019 BLOCK E
