Most of the region from the Somme to the mouth of the Yser is comprised within the two French departments of Pas-de-Calais and Nord, and the Belgian province of West Flanders. Pas-de-Calais is the French equivalent for the Strait of Dover, and the department is so called because its shores are mainly washed by that narrow neck of sea. The department of Nord lies to the north and east of Pas-de-Calais, and merges into the Belgian province of West Flanders.
Nearly the whole of it is a plain, and much of it is as flat as the Fen district of Lincolnshire. A line of low heights runs south-east from Gris Nez,[8] and forms the watershed between the rivers running to the North Sea and those which empty themselves into the English Channel. The most important river of the region is the Lys, a tributary of the Scheldt. It rises in the heights just mentioned, and winds across the country north-eastwards to join the Scheldt at Ghent. Notice very carefully the course of this river, for it crosses the country almost midway between the two most important towns in the region from the Scarpe to Nieuport--the French city of Lille, and the Flemish city of Ypres.
[Illustration: Bird's-eye View of the Country from Arras to the Sea.]
From Arras to the sea near Ostend is a distance of over sixty miles. Nearly the whole of this stretch of country is a dead level. There is a crescent of low heights south of Ypres, but elsewhere, save at and near Cassel, about eighteen miles west of Ypres, there is not a hill worth mention. The hill of Cassel rises suddenly from the plain to a height of 515 feet, and from the summit there is a very extensive view. It is said that thirty-two towns and a hundred villages can be seen from this windmill-studded hill. What is called the Mont des Cats is about the same height as the hill of Cassel. It stands almost on the frontier, to the south-west of Ypres, and was of the greatest importance to the Allies, for it was the key to their position north of the Lys.
A British and a French soldier chatting together in Flanders.]
I have already told you something of the ancient and beautiful city of Arras.[9] It is the capital of the department of Pas-de-Calais, and stands on the Scarpe, a tributary of the Scheldt. The old province of Artois, of which it was the capital, has changed hands very often during the course of its long and warlike history. It has been successively French, Burgundian, Flemish, Burgundian, German, and Spanish, and it finally came into the possession of France in 1640. You will remember that Arras, the capital, was formerly famous for the tapestry hangings known by its name. The manufacture, however, has long been extinct, and the city has now such varied industries as soap, oil, cast iron, salt, sugar refining, lace making, and the manufacture of agricultural implements. It is also one of the chief grain markets of France.