WHAT IS A WALL, AFTER ALL?

A lighthearted but searching and intelligent exploration of the concept and lore of walls, from dry-stone structures to honeycombs and tin cans. Succintly phrased in sprightly verse (``There are brick walls and thick walls and walls owned by cats,/and deep underground there are cave walls, with bats''), supplemented with labels (``arch''; ``picture rail'') and remarks of the appealing Humpty-Dumpty-like figures that people Baron's carefully limned settings, plus the good egg himself, who adds an extra comic note to every spread. The idea is developed with imagination and in surprising depth, touching on structural strength, the old and new, diverse uses and surfaces, and even inhabitants, like toads or slugs. With much intriguing detail— and a particularly intriguing title spread of a many-cornered wall that, in Baron's artful perspective, makes a straight line across the pages: excellent nonfiction, sure to amuse. (Nonfiction. 5-9)