In this paper we present the characteristics of Type III solar bursts from 4 to 2 MHz, as determined from 218 bursts detected by an antenna/radiometer package aboard OGO-IlL These data represent the first large sample of information on low-frequency solar bursts and the first dynamic spectra with high time resolution obtained below ionospheric cutoff frequencies. The peak flux densities at 3.5 MHz average approximately 1 X 10-" W m ' Hz ', and have a range of (1-110) X 10-' W Hz '. The average drift rate over the (4-2)-MHz band is 0.095 + 0.010 (m.e.) MHz sec '. At 3.5 MHz the c-folding duration averages 23.3 + 1.4 seconds and implies a coronal-electron temperature of 2.6 + 0.1 X 10' K at 5.5 R0 if collision damping is assumed. Type V continuum followed the Type III bursts in 1.8 percent of the cases studied. No Type II or Type IV events were observed at these frequencies; evidence for Type I radiation is inconclusive.