[Illustration: GENERAL FAYOLLE INSPECTING THE CONQUERED LINES.] The offensive methods acquired also greater suppleness, and the new arm--=the tank=--came to the relief of the infantry. [Illustration: THE DOTTED ZONES REPRESENT THE GERMAN LINES OF RESISTANCE.] THE SOMME BATTLEFIELD. The battle extended over the Picardy plateau, south and north of the Somme. Before the war, the region was rich and fertile, the chalky ground having a covering of alluvial soil of variable thickness. The slopes of the undulating hills and the broad table-lands were covered with immense fields of corn, poppies and sugar beet. Here and there were small woods--vestiges of the Arrouaise Forest, which covered the whole country in the Middle-Ages. There were scarcely any isolated houses, but occasionally a windmill, farm or sugar-refinery would break the monotony of the landscape. The villages were surrounded with orchards, and their low, red-tiled houses were generally grouped around the church. The plateau was crossed by wide, straight roads bordered with fine elms. The war has robbed the district of its former aspect. The ground, in a state of complete upheaval, is almost levelled in places, while the huge mine-craters give it the appearance of a lunar landscape. The ground was churned up so deeply that the upper covering of soil has almost entirely disappeared and the limestone substratum now laid bare is overrun with rank vegetation. From Thiepval to Albert, Combles and Péronne, and from Chaulnes to Roye, the ground was so completely upturned as to render it useless for agriculture for many years to come, and a scheme to plant this area with pine trees is now being considered. Nearly all the villages were razed, and now form so many vast heaps of débris. This battlefield is a striking example of the total destructions wrought by the late war. The Topography of the Ground and the Enemy Defence-works _North of the Somme._--The battle zone, bounded by the rivers Ancre, Somme and Tortille--the latter doubled by the Northern Canal--forms a strongly undulating plateau (altitude 400-520 feet), which descends in a series of hillocks, separated by deep depressions, to the valleys of the rivers (altitude 160 feet). The Albert--Combles-Péronne railway runs along the bottom of one of these depressions. The higher parts of the plateau form a ridge, one of whose tapering extremities rests on the Thiepval Heights, on the bank of the Ancre. Running west to east, the ridge crosses the Albert-Bapaume road at Pozières, passes Foureaux Wood, then north of Ginchy. It is the watershed which divides the rivers flowing northwards to the Escaut and southwards to the Somme. The second line of German positions was established on this ridge, while the first line extended along the undulating slopes which descended towards the Allies' positions. There were other enemy positions on the counter-slopes behind the ridge.