"They came up from behind the line of trenches," replied Rob, "and that makes it look as if they couldn't be German machines. Besides, the invaders all use a model that is called a Taube, which is different from these."
"But why d'ye suppose they didn't climb up before now, and tackle that monster Zeppelin, so as to put it out of business, or chase it off?" inquired Tubby.
"They had their reasons, I suppose," he was told by the patrol leader. "No matter what they may have been, we're not interested. It's enough for us to watch what's going to happen from now on."
"I'll be jiggered if the Zeppelin isn't going to have it out with them!" exclaimed Merritt. "Did you see that little puff of what looked like smoke? They've got some sort of gun aboard, and mean to try and riddle the aëroplanes with it!"
"Whew! talk to me about excitement, this has got everything I ever knew beaten by a mile!" admitted Tubby.
"You notice that both the monoplanes manage to keep pretty far away from the dirigible," Rob told them. "And see how they bore up in circles all the while, too, getting higher right along."
"What's the idea of that?" asked Merritt.
"For one thing it'll put them on equal terms with the Zeppelin so that they can send back shot for shot," explained the other. "But unless I miss my guess they mean to try a bigger scheme than that, if once they can get above the airship."
"You mean drop a bomb down on it, don't you, Rob?" Merritt asked.