"I ought to know," deplored Bob. "Never was sent out to do an aeroplane story when I was on the _Chronicle_. I've read quite a lot about planes since the war began. Mostly about the newer types, though. That Antoinette of theirs isn't one of them. It's a fairly old-timer. I'm going to hunt up that dihedral angle puzzle in my dictionary." Back in camp barely in time for mess, Bob was forced to postpone his search for information concerning the mystifying angle. Returned to barracks from the mess hall he consulted a medium-sized, fat, black dictionary. "Here you are," he presently informed his still unenlightened bunkies. "Here's a picture of Auntie, and here's a Bleriot. See the difference? See the way the wings of this Antoinette are set in a slight V? There's your old dihedral angle. Look at this Bleriot. Its one plane is set in a rigid horizontal line. Now I'm going to read up on this. Oh, wait till to-morrow. I'll make the Twinkle Twins think I'm the man that taught Cousin Emile how to fly." "Those two must have done a lot of studying by themselves," observed Roger. "I suppose being at Standford University has helped them some. I've heard that it's a fine college. Many of its students have gone into the aviation corps." "Oh, those Twinkles have just absorbed knowledge of aeroplanes like a sponge takes up water," was Bob's sage opinion. "They've made it their chief interest in life. Sort of following in their cousin's footsteps, you know. They're lucky to have had the chance." "I suppose it's hard for ordinary enlisted men in the aviation corps to get a chance to fly," mused Roger. "Our training must be easy beside what they have to go through." "Most of 'em haven't the foundation to start with," rejoined Bob. "It takes a trained mind to get away with all a man has to learn before he ever starts to fly. Then again, with all he knows he may never develop into a flyer. It may not be in him to make good. It's a great game, but I'll bet it carries a lot of disappointed sore-heads along with it. I'd never want to tackle it. I'd sure be one of 'em." The tardy arrival of Ignace who had been on detail in the mess kitchen of late, turned the conversation back to the subject of the Twinkle Twins themselves. The Pole was duly regaled with an account of the afternoon's adventure, to which he listened in rapt silence. Much to the surprise of his bunkies, he earnestly begged his Brothers not to introduce him to the illustrious twins on the morrow. "You no bring here," he entreated. "What's the matter with you, Iggy? They won't bite you." Jimmy finally grew a trifle impatient. "We're going to bring 'em up here on purpose to meet _you_, 'cause you can't go to the 'Y' with us to meet _them_. Do you get me? That goes."