Some writers regard electromagnetism as a well-understood and even as a closed field of study. Maxwell’s equations can be accepted and all that is needed is to find appropriate solutions. This, however, is an onlooker’s view, practitioners know that there are many fundamental problems to be investigated. Partly this is due to the vast range of electromagnetic phenomena and the even greater range of applications. Then there is the inherent complication of the interaction of electromagnetic energy with matter. Also there are geometrical features inherent in electromagnetic fields and only recently have numerical methods become available which make it possible to study the importance of local and global geometries.