XII. Researches in spectrum-analysis in connexion with the spectrum of the sun.— No. V

Abstract It has long been clear that the means placed at our disposal by photography for studying the solar spectrum enable us to construct maps of the region more refrangible than b on a much larger scale than those hitherto employed. At the same time, as our knowledge of the molecular conditions under which changes in spectra occur is increased, it becomes neccessary to embrace more and more detail in the inquiry.