Well this shows that you didn't consider the really excellent problem set at the end of these books (BTW I think they are masterpieces; concerning classical physics they are among the best sources to learn from, although sometimes they are a bit outdated, e.g., in the use of the "ict convention" for special relativity or in the avoidance of the Dirac ##\delta## distribution (although it was in fact Sommerfeld who invented the concept some decades before Dirac). Anyway, you find the treatment of the edge effect as problem II.4 as an elegant application of conformal mappings for 2D potential theory). Note that all problems have well-worked out solutions!