Hidden Pictures

In one of the most fun and innovative children's art books in years, Bolton offers her audience a taste of some of the visual oddities artists have been incorporating into their work for centuries. (Even the cover requires the use of the reflective sheet carefully stitched into the back of the book.) ``Every picture tells a story,'' says the author, ``but some pictures tell more than one.'' She goes on to present anamorphic pictures (which can only be viewed from certain angles), distorted pictures and a variety all kinds of optical puzzles. Readers will feel like discoverers as they view the work of Salvador Dali (``The Face of Mae West'' yields two strikingly different images); ``The Ambassadors,'' with the artist's bold and cynical (albeit distorted) depiction of a skull; and Gauguin's self-portrait craftily concealed in his ``Old Women at Arles.'' Written in straightforward language, the text suggests the boundless enthusiasm of a teacher who can make classroom walls seem to disappear through pure joy. Several hidden-picture projects provide added visual treats. A stylish and informative tour-de-force. Ages 9-up. (Mar.)