The specific intensities of nonparallel light in the direction
of a stellar source, such as the sun, resulting from multiple
scattering and diffuse ground reflection of a unit flux of
parallel radiation incident on a plane parallel, Rayleigh
atmosphere, equivalent to the Earth’s atmosphere in composition
and density, are evaluated following S. Chandrasekhar's
extension of the Rayleigh theory. Values are given as a function
of direction of the source and normal optical thickness covering
the visible and near ultra violet spectrum. It is shown that the
flux resulting from such nonparallel radiation, for a
sufficiently small solid angle (10-3 radian) around the source,
when the latter is within 50° or less of the vertical, is of the
order of 10-5 of the reduced flux of the direct solar beam, for
radiation within the visible range. The relative importance of
the scattered light increases with normal optical thickness and
zenith distance of the source. It is pointed out that certain
observations of apparent atmosp