Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard and Dr. Paul Kipfer
1931
1931
1911
1916
circa 1920
1918-1922
1926
1921
1926
1910-1930
1930
1915
1927
1915
1915
circa 1930
1918
1931
circa 1920
1915-1925
1920
circa 1910
1914-1920
1914-1918
1920-1929
1912
1931
1917
1955; 1830
1919
1910-1930
1921-1930
1920-1925
1917
1910
1915-1917
1910
1918-1920
1914-1916
c.1912
1918
1921
1914
1918
1912-1922
1915-1925
1915-1918
1914-1918
1914
1913-1923
1925-1928