Suddenly, the echo of a crash came out of the forest in front.

He stood erect, listening intently, and the sound rose again, but it was not an echo now.

It was real, and he knew that the battle was at hand.
The crashes became continuous.

Mingled with them were shouts, and a cloud of smoke began to float above the trees.

The French fired a cannon as a signal, and, before the echoes of its report rolled away, every man dropped ax or spade, and was in his place, weapon in hand.
The noise of the firing in front grew fast.