The nature of the soil was such that revetment was of little avail. Even machine-gun pits revetted with close-lagged timbers--that is to say, with their walls supported by a continuous lining of thick planking--caved in. The result was that the struggle with the elements almost took precedence over the struggle with the enemy. The carrying out of reliefs became a question of many hours, and entailed great exhaustion to the troops. The labour required for trench maintenance was far in excess of the resources of the Division. Attempts were made to dig out the trenches with their sides at a slope of 6/1, which would enable them to stand in spite of the incessant pressure on their sides due to the absorbed water. The soil was, however, of such a nature that digging in its sodden state imposed an immense physical strain on the men. Not only was the weight of the mud on the shovel considerable, but the mud adhered to the face of the shovel and could not be flung clear of the trench. In consequence, the men often had to hoist the shovel with its load out of the trench, leaving the earth to be scraped from the shovel by a man working above ground. In spite of the increasing labours of the men, as long as the wet weather continued it was only possible to keep the trenches sufficiently open to enable troops to pass along them with difficulty. In some cases, notably in Campbell Avenue, even this was not possible, and the trench became temporarily unfit for use. Subsequently the frost came, and the labours of trench maintenance, to the delight of all, suddenly ceased. The sides of the trenches stood as though they had been carved out of wood. Officers and men began to take a fresh outlook on life. For the first time for many days they went dry-shod, and began to forget the unpleasant feeling of a mud-sodden kilt chafing the back of the knees, and of muddy water oozing between the toes at every step. But this short-lived return to dry trenches only accentuated the miseries of the inevitable thaw, for the last state became worse than the first. Not only did the clay trenches on which so much labour had been expended collapse _en bloc_, but the action of the frost on the chalk made it crumble. In consequence the chalk trenches collapsed universally. The entire trench area became a ruin. The situation was such that strong measures alone could deal with it. The mining could not be discontinued, as this would involve too serious a risk. All other work was, however, stopped, and the 8th Royal Scots and the Reserve Brigade were all employed on restoring order out of this most appalling chaos. Even with this amount of labour available, as long as wet weather with short intermittent periods of frost alternated, more earth and chalk fell into the trenches day by day than could be cleared out in a day by the available working parties.