The German preparations for the attack had not been unobserved and it was fully expected upon the {83} morning of the battle, but what was not either expected or desired was the ground mist, which seems to have been heavier in the southern than in the northern portion of the line. So dense was it that during the critical hours when the Germans were pouring across No Man's Land it was not possible to see for more than twenty yards, and the whole scheme of the forward defence, depending as it did upon machine-guns, placed in depth and sweeping every approach, was completely neutralised by this freak of nature, which could not have been anticipated, for it was the first time such a thing had occurred for two months. Apart from the machine-guns, a number of isolated field-guns had been sown here and there along the front, where they had lurked in silence for many weeks waiting for their time to come. These also were rendered useless by the weather, and had no protection from the German advance, which overran and submerged them. The devastating bombardment broke out along the line about five o'clock, and shortly after ten it was known that the German infantry had advanced and had invaded the whole of the forward zone, taking a few of the redoubts, but in most cases simply passing them in the fog, and pushing on to the main British line. As it is impossible to give the experiences of each redoubt in detail, the story of one may be told as being fairly typical of the rest. This particular one is chosen because some facts are available, whereas in most of them a deadly silence, more eloquent than words, covers their fate. The Enghien redoubt was held by Colonel Wetherall with a company of the 2/4 Oxford and Bucks Light Infantry {84} upon the front of the Sixty-first Division. The redoubt formed the battalion headquarters, and was connected to brigade headquarters by a cable buried eight feet deep. In front were two companies of the battalion in the outpost line; behind was the fourth company ready for counter-attack. Early in the morning heavy trench-mortar fire was raining bombs upon the redoubt, and the wire was flying in all directions. At 6 the redoubt was so full of gas that even the masks could not hold it out, so the men were ordered below and put up gas blankets to fend it off. This could be safely done, as when gas is so thick it is not possible for the stormers to advance. At 6.15, what with fog and gas and blurred respirators, it was hardly possible to see anything at all. At 7.30 the gas cleared and there was a shower of high explosive shells with shattering effect. At 9.30 the barrage lifted and the garrison rushed up from their shelters and manned their posts, but the fog rolled white and thick across their vision. The cloud banked right up to their wire, while from behind it came all the noises of the pit. So nerve-shaking was the effect that some of the outlying men came creeping into the redoubt for human company.