The message was flashed over the wire, and a few moments later word came that the battery was in readiness.
"Fire!" commanded the captain.
That was an extraordinarily interesting moment to Don Hale.
The operator had scarcely ceased speaking when, from the hill to the rear, came the report of one of the howitzers, and as the projectile, describing a parabola, passed overhead, making the same screeching, screaming sound with which he had become so familiar, Don once more directed the glasses upon the wireless station.
Breathlessly, he waited.
"Ah-h-h-h!"
A long-drawn-out exclamation came from his lips.
A cloud of black smoke suddenly shot up in the distance, completely shutting from view the object upon which he had his eyes so intently fixed. A few seconds later came a faint, dull boom.
What had happened?
Don could not tell. But, with fascinated attention, the boy watched the swirling black mass rolling along the surface of the ground and spreading slowly upward and outward, until it suggested the rounded form of a huge tree.