No registration could, of course, take place, but long practice enabled the gunners to put down a very accurate barrage without this desideratum.
Opposite the Division the Hindenburg Line commenced with an outpost line 750 yards distant on the left and 250 yards on the right.

This was out of sight of our front trenches by reason of the curve of the ground.

Half a mile behind this came the main system, consisting of two trenches 200 yards apart, the whole guarded by most formidable belts of wire about 150 yards in depth.

The interval between outpost and main systems was sown with well-sighted and concealed machine gun positions.

A mile farther on, and on the opposite side of the valley for the most part, ran the support system, similar to the main system.
One and a half miles farther back again was the reserve system, of which only machine-gun dug-outs were completed, and a small amount of wire had been erected.
Two battalions of tanks, each of thirty-six tanks, were allotted to the Division.