Spaced-receiver observations of the 19�7 MHz radio emission from Jupiter during 1963 and 1964 demonstrate that many of the so-called bursts with quasiperiods of 1-10 sec are caused by the sweeping of an interplanetary diffraction pattern across the receiver by the motion of scattering irregularities in the solar wind. Measurements made on these scintillations include arrival time differences at spaced receivers, scintillation rate, angular position scintillation, and the width of the scattered angular power spectrum.