THE EARLY DAYS OF GAMMA-RAY ASTRONOMY

The aims of gamma-ray astronomy were to establish both, the sources of cosmic rays and the seats of nucleosynthesis. The 1950's could be cal led the decade of predictions, when both roots came together and sourc e strengths were predicted on the basis of radio-astronomical data and expectations of steady state cosmology. The 1960's were the decade of disappointment, because detectors employed then had too little sensit ivity and too high background. The 1970's, the decade of discoveries w ere opened with OSD III seeing the milky way in gamma-rays, followed b y SAS 2, Cos-B, SMM and others. And the 1980's were the decade of prep aration for the Compton gamma-Pay Observatory: by now, gamma-ray obser vation have turned into a real astronomy and many of the original hope s have been fulfilled.