"A signal," thought Jack. "I wonder if it will be answered."
He then became aware of a movement on the part of the air pilot. Till that moment he had not noticed the least sign of life from the wheel man. Now there came a soft _blob_ and a red light shot into the air.
Almost instantly there again was darkness.
"By Jove!" whispered Jack to himself, amazedly. "This certainly is marvelously fast work!"
For a while Jack was content to gaze about him in idle wonder. He seemed indifferent to his plight. He drank in the scenes about him, gazed interestedly at other air-craft that passed them, and watched the sky begin to turn a dull slate color. It was the dawn of another day of carnage.
Others, too, were on the watch for these faint signs of day. From somewhere came the long, awful boom of a huge cannon.
Jack tried to get up, but fell back to his former position. He only then realized that he was chained to his seat. He had a certain amount of freedom, but beyond that he was a prisoner, helpless.
"Well," mused Jack upon this discovery, "even if my hands and feet were free, I could not escape from this height. We must land some time, and then I'll have more need to use them."
So Jack settled back to watch developments. Now everything was astir. A faint murmur was wafted to him on the morning breeze.
He could see the soldiers moving about, the great cannons and howitzers beginning to lumber onward, the column of Uhlans already in saddle, and the hundreds of air-craft rising to greet the early sun's rays.
"It's wonderful!" whispered Jack, fascinated. "Yes, wonderful, but how terrible! This whole array is primed to create nothing but havoc, sorrow, destruction, and death! Gee, but I'm glad the good old United States has no need for such military organization!"
Another sound came to his ears, and cut short his thoughts of America. In an astonishingly brief time, the Army of the Invasion had completed its formations and was on the march, the rank and file, all deep-throated men, singing _Das Fatherland_.
"Good God!" gasped Jack. "They are going to their death with a song on their lips!"
From somewhere in front of these columns came a roar of cannon. The air was filled with shrill, piercing shrieks as tons upon tons of metal, charged with fearful destructive powers, tried to stem the human flood.