iT SUMMARY This report is concerned with the transfer of radiative energy by the lines of a gas of uniform properties in local thermodynamic equilibrium. By means of comparatively simple calculations, the relative intensities ref the potentially strong lines of a simple (hydrogenic) spectrum are computed and these results are interpreted in detail. An important conclusion from these calculations is that the influences of lower state occupation number and line oscillator strength can, under some conditions, be outweighed by factors such as the line width and the local value of the Planck function. The remainder of the report is concerned with the numerous weak lines associated with high quantum numbers. It is shown that these lines can be al...