THE DRAGONS OF NORTH CHITTENDON by Susan Fromberg Schaeffer (Little Simon: $2.95; 208 pp.; ages 8-12).

When the mysterious Northern Lights glow in skies over New England, children who’ve read this imaginative dragon tale will know there’s no mystery at all. Why, even though dinosaurs vanished long ago, it is possible those huge, winged pterodactyls may have left behind an egg or two. . . . Well, isn’t it?

Fantasy or not, the first half of Schaeffer’s book is truly delightful as the reader meets the tribe of fire-breathing dragons from high in the mountains of Vermont. Arthur is the daring baby who swoops through mischief, his mother fearing this recklessness will land him among the enemies who killed his father--humans. But like most boys who thrill in ignoring their mother’s warnings, Arthur launches into adventure anyway.

Soon he finds an abandoned infant crying in a cornfield and, as any potential hero would do, he rescues it. Back in his den, he comforts it with a bottle, but Arthur has conveniently forgotten that if humans drink dragon’s milk, or vice versa, the two creatures are forever bound. In a land of ancient rivalry, this is a problem indeed.

There’s a ring of Camelot here, as, over the years, Arthur and the child try to form a peaceful brotherhood. Mordechai is the friendly bat, Regina the beautiful queen dragon. Fifteen black-and-white drawings by Darcy May add artistic balance to this digest-size paperback. Maybe it was just this adult’s impatience, but by book’s end, dragonhood had dragged for 50 pages, which, in a young reader’s lap, is 50 pages too much.