On a summer's day in 1858, in a garden behind Christ Church College in Oxford, Charles Dodgson, a lecturer in mathematics, photographed six-year-old Alice Liddell, the daughter of the college dean, with a Thomas Ottewill Registered Double Folding camera, recently purchased in London.

Simon Winchester deftly uses the resulting image--as unsettling as it is famous, and the subject of bottomless speculation--as the vehicle for a brief excursion behind the lens, a focal point on the origins of a classic work of English literature. Dodgson's love of photography framed his view of the world and was partly responsible for transforming a shy and half-deaf mathematician into one of the world's best-loved observers of childhood. Little wonder that there is more to ''Alice Liddell as the Beggar Maid'' than meets the eye. Using Dodgson's published writings, private diaries, and of course his photographic portraits, Winchester gently exposes the development of Lewis Carroll and the making of his Alice.