Everything considered, the tanks were not of much assistance to the infantry on the occasion of their first appearance, though they unquestionably caused considerable consternation in the German lines. Owing to delay in production, the British were obliged to employ at the battle of Arras, on April 9, 1917, tanks identical with those which had been used on the Somme and which were, in reality, fit only for training purposes, having only 8-mm. armor. Nevertheless, two battalions were launched on a two-kilometre front, and there is no doubt that they rendered valuable service, the capture by twelve tanks of a German stronghold known as “The Harp” being a particularly noteworthy achievement. Eighty-eight tanks of an improved model, protected with 12-mm. armor, were used in the attack on Messines Ridge, June 7, 1917, but the success of the infantry was so complete on that occasion that the tanks had only an unimportant rôle to play. The torrential rains which fell during the early stages of the Ypres offensive on July 31 turned the battle-field into a broad and treacherous morass, in which tanks were of but little use. The following figures, which were doubtless as well known to Hindenburg as to Haig, explain why the tanks did not sweep everything before them, as it was confidently expected that they would do, and why the Germans were no longer particularly alarmed by their appearance: Battle of Tanks in action Ditched Hit by shells { Arras 60 33 (55%) 7 (2%) First day’s fighting { Messines 88 7 (19%) 4 (5%) { Ypres 133 60 (45%) 37 (28%) It was my understanding at the time that the use of tanks by the British during the fighting on the Somme caused great annoyance to the French High Command, it being asserted that the British had agreed not to make use of their machines until the tanks which the French had under construction were ready, when both armies would make a combined tank attack on a large scale. How much foundation there was for this assertion I do not know, but perhaps it was as well that the British tanks made their début when they did, for the French did not make use of tanks until April 16, 1917, when 132 Schneider tanks attacked between Rheims and the Aisne. “In spite of the congratulations of the commander-in-chief,” reads a French report, “the results did not meet expectations, although wherever tanks were used they led the infantry beyond the advance of the rest of the front of attack.”