Abstract
In 1950, a few years after the detection of the Sun at radiowavelengths by Southworth (1945), two important points were already established: 1 — The theory (Martyn 1946, Ginzburg, 1946) indicates that the thermal bremmstrahlung is dominant. 2 — The transfer calculations by Smerd (1950) and the total flux measurements (Pawsey 1946, Pawsey and Yabsley, 1949) lead to a coronal temperature of one million degrees.