ions were completed, and the two Brigades of the
Divisional Artillery took up new advanced positions alongside the
reinforcing batteries already in line, while the heavies were thickly
aligned close in the rear. The preliminary bombardment broke out about
the middle of July, and at first it was keenly resented by the enemy,
who perceived that we were gradually wrestling the initiative from
him, but when, day after day, our fire continued unabated, he
apparently resigned himself to his fate. Hurricane shoots by field
batteries soon began to make a difference in the appearance of his
trenches, and the heavies, by means of aerial registration, demolished
his strongholds far back over the crest, and destroyed many of his
battery positions. Several thick woods were facing us across the
canal, and these grew thinner, and yet more thin, disclosing cunningly
concealed pill-boxes, which were then dealt with by the heavies, until
at last only a few stumps remained to indicate that a wood had ever
existed there. The enemy's alarm grew daily, and soon our aeroplanes
reported that the hostile batteries were being withdrawn further out
of danger, and that work was proceeding feverishly upon new defences
far behind his lines. By this time we had complete control of the air,
and the heavens were alive with our aircraft, though the enemy tried
his best to equalise matters by bringing along his famous "travelling
circus" to the scene of action, and many thrilling fights were
witnessed. The batteries were subjected to much chemical shelling
during the night, and the enemy were known to bring forward special
guns under cover of darkness for this purpose, and to withdraw (p. 050)
them out of range again before daybreak.

It was during this period that he introduced the new mustard gas for
the first time, and it must be admitted that he surprised and
inflicted considerable casualties on us at first by this latest
specimen in his assortment of poison.

Our initial attack had to be postponed for several days, as the
French, who came in immediately on our left, were delayed in putting
in their appearance, consequently they had many hours' bombardment to
make up, but, when it did commence, it was no uncertain one, and the
noise was terrific. In the meantime our bombardment was continued
also, though in a lesser degree, and the destruction of the enemy's
lines was, as far as we were able to judge, thorough and complete.

This delay proved