On July I, after a week's prolonged bombardment, the British 4th Army (recently created and placed under Rawlinson) at tacked with 15 divisions on a front of 15 m. north of the Somme, and the French with five divisions on a front of 8 m., mainly south of the river, where the German defence system was less highly developed. The unconcealed preparations and the long bombardment had given away any chance of surprise, and in face of the German resistance, weak in numbers but strong in organiza tion, the attack failed along most of the British front. Owing to the dense and rigid wave formations that were adopted the losses were appallingly heavy. Only on the south of the British front, near Fricourt and Montauban, did the attack gain a real footing I in the German defences. The French, with slighter opposition, and being less expected, made a deeper advance.
This setback negatived the original idea of a fairly rapid pene , tration to Bapaume and Cambrai, and Haig adopted the attrition method of limited advances aimed to wear down the German strength. Rejecting Joffre's desire that he should again throw his troops frontally on the Thiepval defences, the attack was resumed on the southern British flank alone, and on July 14 the capture of the Germans' second position offered the chance of exploita tion, which was not taken. From now onward a methodical but costly advance continued, and although little ground was gained the German resistance was seriously strained when the early onset of winter rains suspended operations in November. The effect, however, can be exaggerated, for it did not prevent the Germans withdrawing troops for the attack on Rumania. But in one re spect the Somme shed a significant light on the future, for on Sept. 15 the first tanks (q.v.) appeared. Their early employment
before large numbers were ready was a mistake; losing the chance of a great strategic surprise, and owing also to tactical mishan dling and minor technical defects they only had a limited success. Although the higher military authorities lost faith in them, and some urged their abandonment, more discerning eyes realized that here was a key which, when properly used, would unlock the trench barrier. The Somme offensive had a further indirect effect, for its relief to the Verdun pressure enabled the French to prepare counter-strokes, carried out by Mangin's corps on Oct. 24 and Dec. 15, which regained most of the lost ground with small casu alties. These economic successes were due to a revival of surprise, to a more elastic use of the limited objective method, and to a high concentration of artillery, with a minimum of infantry, to occupy the defences crushed by the guns.