on the 13th. Boxes 20 feet long had first to be made & these were carried up to the trenches; pits three feet deep were dug as emplacements for the boxes immediately under the parapet so as to give as much cover as possible from shell fire. We had to install 300 cylinders – each box holding 20 cylinders. The special company Royal Engineers chose the emplacements at points in our trenches where we are nearer the Germans: these places or bays were numbered & labels made for them so that they could be recognised when the time came for putting in the cylinders. the cylinders are brought up in motor lorries to a selected spot behind our line where it is more or less safe from shelling; this is of course done at night – fatigue parties