Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard and Dr. Paul Kipfer
1931
1931
1916
circa 1920
1935
1918-1922
1926
1930-1940
1920-1940
1921
1926
1942
1925-1940
1930
1915
1940
1927
1938
1915
1915
1940
1938
1938
1938
1935
1938
circa 1930
1940
1918
1931
1942
circa 1920
1915-1925
1920
1914-1920
1935
1914-1918
1940
1936
1920-1929
1934
1912
1929-1935
1936
1931
1917
1937
1937
1935
1938
1938