On the observation of the F corona in the vicinity of the solar limb

Theoretical calculations led Calbert and Beard to predict a much lower intensity of the F corona near the solar limb than the one generally accepted. We show that this does not agree with recent observations, especially airborne ones obtained far above the lower atmosphere. The measurements made on the ground during the eclipse of 1970 March 7 confirm the classical models. We suggest that new observations should be made in order to allow a choice between the apparently inconsistent interpretations of the measurements concerning the external F corona. Subject heading: corona, solar