Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard and Dr. Paul Kipfer
1931
1931
1911
1927
1916
circa 1920
1918-1922
1926
1928
1926
1911
1921
1926
2000-100 BCE
1920-1928
1925
1921-1926
1922-1923
1917-1918
1910-1930
1930
1922-1923
1924
1927
1923
1934
1915
1910-1920
1922-1923
1923
1915
1922-1923
1914-1918
1920-1929
1920-1930
1914-1918
1910
1927
1915
1920
1915
1924
1910
1928
1925
1930
1910-1920
circa 1930
1928
1918
1931