Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard and Dr. Paul Kipfer
1931
1931
1911
circa 1890
circa 1890
1916
circa 1890
circa 1920
circa 1890
1889
circa 1900
1898
1899
1880-1920
after 1903
1935
1918-1922
1926
1928
1926
1911
1884
1892-1900
1880-1900
1880-1900
1886
1901
1890-1899
1890
1901
1921
1926
1910-1936
1894-1904
1894
1932
2000-100 BCE
1880-1920
1906-1915
1894-1904
1880-1890
1895-1910
1901-1930
1898-1899
1900-1910
1896
1900-1910
1894-1904
1880-1920
1901-1930
1920-1928