AbstractThe interactions between two dielectric bodies in an outer field show rather strong deviations from the “long distance laws” if the surfaces of the two bodies approach contact. Image forces occur that require another type of mathematical procedure. Instead of a partial differential equation an integral equation has to be solved. In the special case of cylindrical bodies these solutions lead to Fourier transforms that can be integrated explicitly (in contrast to the case of two spheres where the integral equation is not yet solved).