ARGONNE  , a rocky

forest-clad plateau in the north-east of France, extending along the borders of Lorraine and Champagne, and forming part of the departments of Ardennes, Meuse and Marne . The Argonne stretches from S.S.E. to N.N.W., a distance of 63 m. with an average breadth of 19 m., and an average height of 1150 ft . It forms the connecting-link between the plateaus of Haute Marne and the Ardennes, and is bounded E. by the Meuse and W. by the Ante and the Aisne, which rises in its southern plateau . The valleys of the Aire and other rivers traverse it longitudinally, a fact to which its importance as a bulwark of north-eastern France is largely due . Of the numerous forests which clothe both slopes of the plateau, the chief is that of Argonne, which extends for 25 M. between the Aire and the Aisne . For Dumouriez's Argonne campaign in 1792, see FRENCH REvoLUTIONARY WARS .