A story of Mississippi sidewheeler days, and of a winter spent, icebound in the upper reaches, with a family living on board the Johnny Smoker, and cutting a stand of timber, while spare time is spent unravelling the mystery of the clue to how the boat should be loaded for best performance. On board is -- in secret -- the grandson of the man who built the boat. But it is the family of the captain, and particularly the youngest daughter, aged ten, who unearth the solution. A good story, with a touch of mystery, good early American background, and good characterization.