We carefully study the e→m and e→0 limits of the
Reissner-Nordstr\"om spacetime using Geroch's definition of limits of
spacetimes. This is implemented by embedding the one-parameter family of
spacetimes in anti-de Sitter space, and as a result we obtain metrically
correct Penrose diagrams. For e→m two distinct limits are
studied.Comment: 23 pages, 13 figure