Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard and Dr. Paul Kipfer
1931
1931
1911
1916
circa 1920
1935
1918-1922
1926
1921
1926
1930
1915
1927
1915
1915
1935
circa 1930
1918
1931
circa 1920
1915-1925
1920
1914-1920
1935
1914-1918
1936
1920-1929
1934
1912
1929-1935
1936
1931
1917
1937
1937
1935
1932
1955; 1830
1919
1921-1930
1934
1920-1925
1917
1915-1917
1918-1920
1914-1916
c.1912
1935
1932
1918
1933