Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard and Dr. Paul Kipfer
1931
1931
circa 1920
1935
1926
1921
1926
1930
1927
1935
circa 1930
1931
circa 1920
1920
1935
1936
1920-1929
1934
1929-1935
1936
1931
1935
1932
1955; 1830
1921-1930
1934
1920-1925
1935
1932
1933
1921
1925-1928
1920-1925
1927-1929
circa 1927
circa 1930
circa 1930
1936
1925
1921-1926
1934
1924-1927
1922-1923
1922-1923
1922-1923
1922-1923
1935
1920-1936
1920-1929
1927
1925-1935