The purpose of this monograph is to review the known physical aspects of two unusual forms of atmospheric luminous phenomena, to deduce their characteristics and properties, and to promote efforts to improve their understanding. These two forms, called ball lightning and bead lightning, have visual images that differ from the linear image associated with normallightning. The terms "balliightning" and "bead lightning" are used to denote atmospheric luminous forms which are occasionally observed and have the geometrie shape suggested by their name. Vet, it is possible that neither phenomenon...