The effect of fine structure on the Stark components of Ha.

The Stark effect was discovered in the Balmer series by (1) J.S. Stark (Fig.l.) in October 1913. In this series the effect appears to be perfectly symmetrical, just as the Zeeman effect is in all spectra. The initial theoretical explanation by Epstein left this symmetry intact, and pictured all hydrogen levels as split by the field into evenly spaced sub-levels {Fig.2.}. Taking this view of the subject there appears to be little connection with the Stark effect in ail other spectra, where it is characterised by the appearance of new combination lines and asymmetric displacements of the energy levels. [...