ongest positions
they held on the western front. As far as human ingenuity and military
skill could make it so, the position was impregnable. From its
commanding situation the Germans were able to observe with ease all
the preparations that were in progress in the British lines and
arrange to checkmate them. The value of the position to the Germans in
this area was therefore of supreme value.

For two and a half years the Allied armies in this little corner of
Belgium had held the Germans in check, and during that time they were
almost at the mercy of the German guns on the Messines-Wytschaete
Ridge.

The German front defenses of this position consisted of the most
elaborate trench systems and fortifications, forming a belt of about a
mile deep. Farms and woods around were garrisoned and machine-gun
emplacements were set up in every available corner. Concrete dugouts
of the strongest description were provided for the protection of
garrisons and machine gunners, and nothing that labor and skill could
devise was neglected to make the position indestructible. Yet all this
laboriously constructed defense work that had taken many months to
complete and the strength and skill of thousands were swept away in a
few hours' time.

For nearly two years companies of sappers--British, Australians, and
New Zealanders--had been busily engaged in tunneling under the low
range of hills upon which the German position stood. In these
underground passages engineers had planted nineteen great mines,
containing more than a million tons of ammonite, a new and enormously
destructive explosive. The secret of the mines was so well kept during
the time they were preparing that the Germans seemed to have had no
suspicion of the great surprise in store for them.

At exactly 3.10 in the morning of June 7, 1917, all the nineteen mines
were discharged by electric contact and the hilltops were blown off
amid torrents of spouting flames with a roaring sound like many
earthquakes that could be heard distinctly farther away than London.
Large sections of the German front, supporting trenches, and dugouts
went up in debris amid thick clouds of smoke. To add to the terror of
the defenders of the position the British guns after the explosions
shelled the salient steadily until preparations were completed for
attack. Then the British infantry under Field Marshal Haig and General
Sir Herbert Plumer advanced with a rush to the assault and the German
front