It is immediately effective, for casualties never reach the same height as in the Somme, and prisoners are much more numerous.

The lines for the two battles show the difference vividly.

But mark the big curve downward of the STRENGTH line.

Casualties are now not so easily replaced.
MESSINES, YPRES, PASSCHENDAELE .-- Before STRENGTH is fully restored the Messines ridge is rent with mines (June 7th) and taken.

July is devoted to preparation: STRENGTH reaches its zenith, guns still increase, and on July 31st the Battle of YPRES opens the great northern offensive.