  We consider Donaldson-Witten theory on four-manifolds of the form $X=Y \times
{\bf S}^1$ where $Y$ is a compact three-manifold. We show that there are
interesting relations between the four-dimensional Donaldson invariants of $X$
and certain topological invariants of $Y$. In particular, we reinterpret a
result of Meng-Taubes relating the Seiberg-Witten invariants to
Reidemeister-Milnor torsion. If $b_1(Y)>1$ we show that the partition function
reduces to the Casson-Walker-Lescop invariant of $Y$, as expected on formal
grounds. In the case $b_1(Y)=1$ there is a correction. Consequently, in the
case $b_1(Y)=1$, we observe an interesting subtlety in the standard
expectations of Kaluza-Klein theory when applied to supersymmetric gauge theory
compactified on a circle of small radius.
