Observations at the 7 March 1970 eclipse were carried out for the purpose of measuring an expected difference in color between the radially and tangentially polarized components of the corona. The basic instrument was an array of Wollaston prisms and filters in association with a telescope and camera. Excellent photographs were obtained and are now being analyzed. It is expected that the color difference can be used in determination of the three-dimensional configuration of coronal features.
D. E. Billings, "Color of the K Corona," Appl. Opt. 9, 2631-2634 (1970)