Secular Variation of the λ9.4-CM Radio Emission from Discrete Sources.

Observations of the 94-cm radio emission from discrete sources made with the 50-foot reflector in 1953 and 1962 have been combined to investigate secular variation of the radiation. The intensity of Cassiopeia A relative to Cygnus A showed a significant decrease over the 8.8-year interval. The smaller changes observed for the other five sources investigated were comparable with or smaller than the measurement uncertainties.