Reason slot meter, c.1920.
1918-1922
1918-1922
1918
1920
1917
1922
1923
1922-1923
1922-1923
1922-1923
1922-1923
circa 1920
1920
1955; 1830
1921
1918
1918
1921
1923
1918
1919
1917
circa 1920
2000-100 BCE
1917-1918
1923
1934
1918-1920
1920
1920
1990-96
1920
1920
1930 (replica); 1834 (original)
1801-1892 (prepared); 1946 (element replaced)
1919
1922
circa 1917
1923
1923
circa 1919
1922-1923
1922-1923
1922-1923
1922-1923
1922-1923
1922-1923
1922
1903 (original); 1982 (model)
1772 (original); 1919 (model)
1918-1920