Fine-Structure Analysis ofH1αandH2α

Methods employed in applying corrections to an observed "doublet" interval to find the true interval and in relating the position of an intensity maximum to that of the components of which it is composed are critically discussed. The need for clearly distinguishing between the position of the center of gravity of even a nearly symmetrical intensity complex and that of its maximum is emphasized. A Fabry-Pérot interferometer was used to examine the fine structure of the ${\mathrm{H}}^1\alpha$ and the ${\mathrm{H}}^2\alpha$ lines. The interval between the main components of the "doublet" is found to be 0.38 ${\mathrm{cm}}^{-1\mathrm{}}$ for ${\mathrm{H}}^1\alpha$ and 0.321 ${\mathrm{cm}}^{-1\mathrm{}}$ for ${\mathrm{H}}^2\alpha$ as compared with 0.328 ${\mathrm{cm}}^{-1\mathrm{}}$ indicated by theory. The relative intensities of the components as revealed by the analysis are approximately in agreement with theory.