''Words and Pictures'' explores three fascinating examples of relationships between artists and writers: the illustrations of ''Paradise Lost'' and ''Pilgrim's Progress''; ''Hogarth and Fielding'', a writer and artist dealing with common material; Wordsworth and Thomas Bewick, a poet and engraver working separately, but imbued with the spirit of their age. A brief coda turns to a fourth kind of relationship, the writers and artists who collaborate from the start, beginning with Dickens and Phiz. Illustrated throughout with a wide variety of examples, this is a book to pore over and enjoy.