  The Kerr solution is generated from the Schwarzschild solution by a simple
combination of real global coordinate transformations and of invariance
transformations acting on the space of stationary solutions of the
Einstein-Maxwell equations. The same transformation can be used to generate a
spinning field configuration from any static axisymmetric configuration. We
illustrate this by generating from the continuous family of Voorhees--Zipoy
vacuum solutions a family of solutions endowed with mass, angular momentum,
dipole magnetic moment and quadrupole electric moment.
