Hardly had Chester delivered his message when a shout told him the German
infantry was advancing to the attack. The lad glanced around, and as he
did so, a sharp order rang out and a moment later the French troops
clamped queer-looking devices over their faces and heads.

Chester knew what they were--gas masks to protect the defenders from
the poisonous vapors of German gas bombs, which, had the defenders not
been protected by masks, would have killed them instantly. A passing
officer said something unintelligible to the lad as he passed and
pointed to the ground. Glancing down, the lad perceived a mask and then
understood that the officer had meant for him to put it on. Chester did
so, though not without some difficulty, for he had trouble adjusting
it. But with his nostrils protected at last, Chester turned to watch
the approach of the enemy.

The Germans came forward in a dense mass, despite the fearful execution
worked in their ranks by the French guns. In the lines of the defenders
dropped huge bombs that sent up dense vapors--the deadly gasses of the
foe--but they caused little harm, for the French were protected. Now and
then a man fell, however; perhaps he had failed to adjust his helmet
properly, or perhaps it was not perfect. But for the most part the gas
bombs had little effect.

The first concerted attack of the German troops availed little; and after
trying for half an hour to gain a foothold in the French lines they
withdrew. But a second attack followed a few moments later. This also was
beaten off. A third attack, however, met with better success.

This time the Germans succeeded in gaining a hold in the French lines,
and this they retained in spite of repeated counter assaults by the