Fine Structure of the Balmer Lines of Hydrogen

Abstract

USING two optical trains, (1) two crossed Lunmer plates, the larger of resolving power 670,000, and (2) an echelon of resolving power 660,000, with a vacuum tube of the Wood form having a 1 cm. diameter capillary, cooled with liquid air, we have determined the wave-length differences between the two well-known components γ and γ″ of H_α, H_β, and H_γ (λ < λ″), and have sought to obtain still further resolution. The doublet separations are shown in the subjoined table together with those given by Houston (Astrophys. Jour., 64, 2, 1926, pp. 81–92), which latter are, in our estimation, the most trustworthy thus far obtained.