Tr F approximately F for dyons

The spatial volume integral of Tr F approximately F is considered which is a static Minkowski space solution for the dyon. It is observed that this gauge invariant integral globally characterizes the ''Yang-Mills'' E-B for the field tensor and the ''electromagnetic'' E-B for the 't Hooft electromagnetic field. Both integrals are found to have the same value which is, in turn, found to be the product of total magnetic charge and electric charge multiplied by a parameter that governs the fall-off of the field. (Author)