"Oh, that's an easy matter," he replied. "I suppose the flyers in the air do it on the same principle that we are in the habit of recognizing automobiles. Why, I have a lad not ten years old who can tell the make of almost any auto the moment he sees it. Generally, if the make of the plane is similar to those attached to the aviator's side he is able to recognize it by the special mark it carries."
"What mark do you mean?" asked Alfred.
"Why, the English and the French mark is in the form of a circle, generally three, each circle being of a different color," was the answer.
"There is one,—why, it's red, white and blue," said Ralph.
"That's correct,—those are the colors of the Allies."
"What are the German colors?" asked Ralph.
Allies' Distinguishing Mark
"Black and white," said the corporal.
"Oh, yes, they have a cross," said Alfred.