Medal commemorating first free balloon stratospheric flight of Professor Auguste Piccard and Dr. Paul Kipfer
1931
1931
1926
1926
1930
1927
circa 1930
1931
1931
1955; 1830
1925-1928
1927-1929
circa 1927
circa 1930
circa 1930
1925
1934
1927
before 1928
2000-100 BCE
1930-1931
1928
1927
1926
1928
1925
1928
1925-1927
1925
1927
1930
1924
1927
1925
1926
1925
1930 (replica); 1834 (original)
1930
circa 1927
1929
1925-1930
1903 (original); 1982 (model)
1925
1926-1928
1990-96
1929
circa 1929
1926
1930
1930
1925-1930