This fourth volume, covering the railways of the departement of l'Yonne, completes the series of books on the railways of Burgundy. In part one, the standard gauge lines of the departement are described. These include the section of the Paris - Lyon main line within the departement, and the various transversal lines which connected with it. Also in part one is a special chapter on the once vast steam depot of Laroche-Migennes. This chapter includes many rare and previously unpublished photographs. In part two, the history of the once extensive metre-gauge systems of the Chemins de Fer de...