Victor Hess (1883-1964), Austrian physicist and discoverer of cosmic rays. In 1911-12 Hess made 10 balloon ascents to determine the source of radiation in the atmosphere. Here he is seen standing in the basket of his balloon around the time of his flight on 7 August 1912, when he rose to a height of over 5000 metres and found that the intensity of the radiation increases rapidly with altitude. Thgis proved that the radiation comes from outside earth. A balloon flight during a solar eclipse showed no reduction in radiation, ruling out the sun as the source. Hess won the Nobel Prize for physics in 1936. NO ADVERTISING USE WITHOUT PRIOR WRITTEN PERMISSION.