  We present a translation and analysis of a cosmic model published by Einstein
in 1931. The paper, which is not widely known, features a model of a universe
that undergoes an expansion followed by a contraction, quite different to his
static model of 1917 or the monotonic Einstein-de Sitter model of 1932. The
paper offers many insights into the cosmology of Albert Einstein in the light
of the first evidence for an expanding universe, and we discuss his views of
issues such as the curvature of space, the cosmological constant, the
singularity and the timespan of the expansion. We argue that retrospective
descriptions of this model as cyclic or periodic are not historically or
mathematically accurate. We find that calculations in the paper of the matter
density and radius of the universe contain a numerical error, a finding that is
supported by writing on a blackboard used by Einstein during a lecture at
Oxford University in May 1931. Our article concludes with a general discussion
of his philosophy of cosmology.
