"A gun!" cried Pierce involuntarily; "looks just like a howitzer; or is it an anti-aircraft gun?"

"Anti-airman gun, no doubt," said Crane; "they heard you were coming down and took precautions."

"But what the devil can he want with a gun?" muttered Pierce, peering at the dark outline.

"And who the devil is he, if it comes to that?" said the Colonel.

"Why, that window," explained Pierce, "that's the window of the room they've let to a paying guest, I know. Man of the name of Green, I understand; rather a recluse, and I suppose some sort of crank."

"Not an anti-armament crank, anyhow," said the Colonel.

"By George!" said Pierce, whistling softly. "I wonder whether things really have moved faster than we could fancy! I wonder whether it's a revolution or a civil war beginning after all. I suppose we are an army ourselves; I represent the Air Force and you represent the infantry."

"You represent the infants," answered the Colonel. "You're too young for this world; you and your revolutions! As a matter of fact, it