Angle iron to support levelling staff at bench mark
1914
1914
1914
1891-1895
1930-1940
circa 1980
1930-1940
1905-1911
1897
1971
1902
1876-1906
1960-1970
1896
1800-1920
1800-1920
1701-1800
1955
1985
1970-1975
1914
1946-1950
1899
1898