  We construct 7-dimensional compact Einstein spaces with conical singularities
that preserve 1/8 of the supersymmetries of M-theory. Mathematically they have
weak G_2-holonomy. We show that for every non-compact G_2-holonomy manifold
which is asymptotic to a cone on a 6-manifold Y, there is a corresponding weak
G_2-manifold with two conical singularities which, close to the singularities,
looks like a cone on Y. Our construction provides explicit metrics on these
weak G_2-manifolds. We completely determine the cohomology of these manifolds
in terms of the cohomology of Y.
