OISE, a river of northern France, tributary to the Seine, flowing south-west from the Belgian frontier and traversing the departments of Aisne, Oise and Seine-et-Oise. Length, 187 m.; area of basin 6437 sq. m. Rising in Belgium, 5 m. S.E. of Chimay (province of Namur) at a height of 980 ft., the river enters France after a course of little more than 9 m. Flowing through the district of Thiérache, it divides below Guise into several arms and proceeds to the confluence of the Serre, near La Fère (Aisne). Thence as far as the confluence of the Ailette its course lies through well-wooded country to Compiègne, a short distance above which it receives the Aisne. Skirting the forests of Compiègne, Halatte and Chantilly, all on its left bank, and receiving near Creil the Thérain and the Brèche, the river flows past Pontoise and debouches into the Seine 39 m. below Paris. Its channel is canalized (depth 6 ft. 6 in.) from Janville above Compiègne, to its mouth over a section 60 m. in length. Above Janville a lateral canal continued by the Sambre-Oise canal accompanies the river to Landrecies. It communicates with the canal system of Flanders and with the Somme canal by way of the St Quentin canal (Crozat branch) which unites with it at Chauny. The same town is its point of junction with the Aisne-Oise canal, by which it is linked with the Eastern canal system.