Besonderhede van voorbeeld: 7020774672008250612

Metadata

Data

English[en]
During summer of 1936, he developed and flew first constant-level balloons made of cellophane from the University of Minnesota.
Spanish[es]
Durante el verano de 1936, desarrolló y voló los primeros globos de nivel constante hechos de celofán de la Universidad de Minnesota.

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