roads, the Canal runs between almost perpendicular cliffs, which for the greater part of this distance vary between fifty and thirty feet high. South of this it runs practically at ground level with, in places, a slight embankment. Right throughout, the Canal wall formed a perpendicular obstacle faced with brick, both west and east banks being strongly wired. The southern portion of the Canal was practically dry, but over considerably more than half of the front covered by the Division a depth of from six to eight feet of water had to be reckoned with.
In addition to the natural strength of the Canal as an obstacle to advancing troops, no pains had been spared to strengthen the whole length, which bristled with well-sited concrete and steel machine-gun emplacements, and had been generally rendered as nearly as possible impregnable. Indeed, we know from statements of German prisoners that it was considered by them to be capable of defence against any possible attack. It is probable that this fact helped to lull the Germans into a false state of security which may in a measure have been responsible for the fact that all our preparations passed unheeded and that the attack did not seem to have been suspected until it actually took place.
The two weak points about the Canal which were destined to have a decisive effect on the outcome of the battle were: (1) the bridges which were necessary for the supply of the enemy troops on the western bank, and so could not be destroyed in good time; and (2) the existence of certain concrete dams which had presumably been built by the enemy to serve as locks to retain the water. Where the Canal crosses the valley of the Omignon, south of Bellenglise, it is banked up above the level of the surrounding country; and without these concrete
