Total Solar Eclipse of October 1, 1940

Abstract

THE Joint Permanent Eclipse Committee of the Royal Society and the Royal Astronomical Society has for some years plans prepared for a number of expeditions to observe, what should be a very good eclipse for study, the total eclipse of October 1, 1940. Prof. J. A. Carroll was to have gone from Aberdeen to Brazil with an objective interferometer and an echelon spectrograph for a study of coronal and chromospheric line contours and wave-lengths. The Royal Observatory, Greenwich, and the Cape Observatory were to have gone to Calvinia for a study of the Einstein displacement of stellar images, for a spectrographic study of the chromosphere with a moving-plate camera and for other work. Prof. H. Dingle was to have gone to a station near the edge of the belt of totality for work on wave-lengths and intensities of chromospheric lines near the cusp. The Solar Physics Observatory and the Radcliffe Observatory, Pretoria, were to have joined forces at Nelspoort for a programme including work on the extreme ultra-violet spectrum of the chromosphere and corona, a study of chromospheric line intensities at different heights with a camera having a plate moving intermittently, and polarization studies of the corona and of the sky close to the eclipsed sun.