_(See the sketch-maps on pages 13, 18, 27.)_
This attempted break-through (July 1-12) soon changed into a battle of
attrition (July 14, 1916, to March, 1917).
The Allies' plan now was gradually to shatter the German resistance by
a continuous push along the whole line, and by vigorous action at the
various strong-points.
The gains of ground diminished, but the German reserves were gradually
used up. In spite of their hastily constructed system of new defences,
the Germans realised the precarious nature of their new lines, and were
forced, in March, 1917, to fall back and shorten their front.
[Illustration: THE PHASES OF THE BATTLE OF ATTRITION.