Cornelia Meigs' books fall into distinct age groups. This is one of her books for ""middle aged children"" -- historical in background and dealing with a tiny facet of history with which few people are familiar. Napoleon's brother, Joseph, lived for a time in southern New Jersey, among the truck farmers, keeping himself in the seclusion of grandeur, and hoping for word that his brother had escaped from St. Helena and was coming to join him. Into this situation came an American lad, raised in France, sympathetic -- romantically so -- with Joseph, and eager to do his part to help him. Just how he helped -- and how he brought Stephen Girard of Philadelphia into the picture is the story of ""The Scarlet Oak"".