Bridges Go from Here to There

Wilson ( What It Feels Like to Be a Building ), a professor of architecture at Catholic University, here conducts an erudite but playful lesson on the principles of bridge constructon. He conveys such essential concepts as gravity, weight and mass, shows how a suspension bridge works and defines such structures as a trussed train bridge and a cantilever, ever mindful to present ideas in terms of a child's experience (``The arch stones . . . are held from pushing further by towers with the strength of elephants''). The black-and-white artwork takes full advantage of the wide, ample pages with plain line drawings of bridges and silhouettes of dogs, monkeys, elephants and primitive people who disport themselves with acrobatic facility. Unapologetically didactic, this brave book dares to introduce scientific concepts not with flashy colors or silly cartoons, but with grace, wit and intelligence. Ages 6-up. (May)