  For an odd-dimensional oriented hyperbolic manifold with cusps and strongly
acyclic coefficient systems we define the Reidemeister torsion of the
Borel-Serre compactification of the manifold using bases of cohomology classes
defined via Eisenstein series by the method of Harder. In the main result of
this paper we relate this combinatorial torsion to the regularized analytic
torsion. Together with results on the asymptotic behaviour of the regularized
analytic torsion, established previously, this should have applications to
study the growth of torsion in the cohomology of arithmetic groups. Our main
result is established via a gluing formula and here our approach is heavily
inspired by a recent paper of Lesch.
