
Whitaker Tunnelling Machine
1921
1921
1924
1920-1925
1915-1925
1925
1915
1926
1926
1915
1915
circa 1915
1917
1918
1918
1922
circa 1915
circa 1925
1919
1915-1925
1926
1915-1925
1915-1920
1915
1924
1923
1920
1920-1925
1918
circa 1925
circa 1927
circa 1915
1926
circa 1920
1915-1925
1926
circa 1920
circa 1917
1920-1925
1919
1920
1950-1911
circa 1925
1915-1918
circa 2000 BCE
700-100 BCE; 1930-1950
circa 1926
circa 1924
circa 1920
circa 1918
1920