 Those new approaches in the study of atmosphere lead to a new science, the synoptic Aerology.In this context, during Belgium's participation to the International Polar Year in 1932-1933, Jules Jaumotte performs automatic cloud photographs at high altitude by balloons, with a method that links the functioning of instruments to their altitude level.During World War II, the Institute was used by the Nazis as a military observatory and was destroyed by the English troops in 1944.