Abstract
We consider the problem of evaluating the Casimir effect by the mode-sum method for a quantum field in a one-dimensional space, in the presence of two point-like boundaries of Dirichlet type, and under the influence of a constant external field - which may be envisaged as a classical gravitatory field near the surface of a planet or a classical electric field in the interior of a flat capacitor. The case of infinitely separated points is also examined. Despite apparent simplicity, the calculation exhibits rather non-trivial aspects. The possibility of an experimental observation of these effects is considered.