When and where necessary, the roof was revetted. The revetting was done with bed boards. The foundations of all beds in the camp were boards placed cross-wise across an iron frame and supporting a mattress made of paper, straw and shavings, and uneven as the Somme battlefield. Many of these boards had been commandeered as firewood during the early stages of the camp, when there had been, as related, a regrettable hitch in the arrangements for our warming. Many more now found their way underground by driblets into the orderlies’ quarters and thence into the recess behind the planks, or were carried direct by the working-party. People clamoured querulously for the missing boards which they had saved from the burning, and of which they had now been robbed. No one except the very few in the secret and an orderly or so had the ghost of a notion what had really happened to them. The Boche when appealed to of course shrugged their shoulders and quoted the equivalent German proverb about eating your cake. What would you? Very nearly all is fair in escapes. The only tools used in the digging of the tunnel were a trowel or “mumptee” (an instrument with a spike at one end and an excavating blade at the other) and the cold chisel. The chisel was useful for levering apart the smooth heavy stones which presented so much difficulty. It seems probable that these stones had once formed the bed of some river and had been worn smooth and packed by the action of the water. Attempts were made to dodge this difficult stratum of stones which retarded progress so seriously, but in the absence of proper instruments it was impossible to gauge the level with any degree of accuracy. A descent of four feet bringing no better results, it was decided to come back to the previous level of about eight or nine feet below the surface. The chamber was just—and only just—sufficient for the earth. When the last sackful[8] had been piled the chamber was practically full of earth from floor to ceiling and in every crevice. [Footnote 8: See the photograph opposite. The sacks were mostly mattresses stolen from beds and quite unaccounted for also!] Orientation was not an easy matter. It was necessary of course only to bear in a general easterly direction as straight as possible. There were rough compasses galore in the camp, but it was very difficult to dig the tunnel straight and the compasses were too small to check errors accurately.