The interferometer pattern due to a group of spectral lines can be expressed as a Fourier series, and the coefficients of this series can be regarded as the quantities to be measured. These coefficients can also be computed in terms of the positions, intensities, and the parameters describing the shapes of the lines. Although the equations cannot be explicitly solved for the latter quantities in terms of the Fourier coefficients, numerical means can be used to find the parameters which best reproduce the observed values. This method has been applied to two plates of ${\mathrm{H}}_{\alpha }$ and ${\mathrm{D}}_{\alpha }$. The results indicate that to fit the observations with the four strongest lines given by the theory it is necessary to make the separations of the two most intense components some 2 percent less than the theoretical value.

• Received 28 December 1936

DOI:https://doi.org/10.1103/PhysRev.51.446