"What was it?" cried Chester.
And, even as he spoke, it came again, the heavy boom of a single huge cannon, followed almost immediately by the crash of thousands upon thousands of rifles. The machine and rapid-fire guns broke loose with their leaden messengers of death, and a bugle sounded:
"To arms!"
CHAPTER XVIII.
THE BATTLE.
Captain Derevaux, who had been sleeping soundly, sprang to his feet, picked up his sword and pistols, and, without even a word to Hal and Chester, dashed from the hut.
"The battle has begun!" cried Hal.
"Come!" exclaimed Chester. "Let's get to some place where we can see. I can't stay here!"
"Nor I!" cried Hal. "Come on!"
The two lads hurried from the hut. As they emerged, a troop of Belgian cavalry swept past them, on the way to the front. The boys followed as rapidly as possible in its wake. Presently they came to a small hill. Climbing to the top, they found they could command a good view of the advancing German columns, which they could see in the distance, and which were even now almost close enough to grapple hand-to-hand with the horsemen swooping down on them.