“If you haven’t run across these men, sir,” Hugh remarked, “of course you could hardly say who they might be.”

“I can give a pretty good guess, though,” came the prompt reply.  “We have been dogged by a pair of spies on former occasions, the one a short Jap, and the other, much taller, undoubtedly a German.  Both of them happen to be famous aviators in their own countries, which was doubtless why they were sent out to discover what the Flying Squadron was doing up here in secret.”

“I suppose their main objects would be to learn the composition of this latest thing in explosives, and to take note of your war aeroplane, so as to steal the improvements,” Hugh went on to say, being desirous of learning all he could while the other was in this communicative frame of mind.

“They would actually have to examine the flier before they could learn what it represents to the army aviation corps; and we keep it closely guarded all the time we are not in the air.  So much of a secret are several things connected with this monoplane, that I cannot mention them, even to such patriotic chaps as you are.”

“And we don’t blame you, sir, surely we don’t!” exclaimed Bud promptly.  “Us inventors have to be pretty careful how we let people see what we’ve struck!  Lots of ideas have been stolen before now.  If my little scheme turns out what I hope it’s going to, I think I’ll hand it over to the Government for use with their war aeroplanes.  Wouldn’t it be just great if a pilot could give his whole attention to the job of dropping bombs and such like, never bothering himself about the wind currents or anything else?  The little Morgan controller would manage all such things automatically.  As the saying is, you press the button and we’ll do all the rest!”

Hugh did not arouse poor Bud from this happy dream.  What was the use?  Better let him have a little more pleasure out of it before confronting him with the cold facts acts in the case.  He must learn soon enough that he was several years too late, and that those wonderful Fathers of Aviation in America, the Wrights, had covered the identical ground some time previous with their Fool-proof Flier.

Luckily they did not have a great distance to go.  The boys, who were staggering under their loads, could not have kept it up much longer, and all of the little party rejoiced when the air pilot announced that they were now within sight of their destination.

Presently they heard voices ahead.  Then came a sudden whirr of machinery.

“My associate, Lieutenant Green, is going to take a little spin for some reason or other,” their escort told them.  “You see, we can reconnoiter the ground wonderfully from several hundred feet altitude; so that we have on several occasions indulged in a flight just in order to scout the land.  We discovered your presence some time yesterday, and were at first greatly puzzled on account of your khaki suits.  We even tried to figure out how a trio of soldiers belonging to the Home Guard could be camping out in that way.  To tell the truth, it was not until I stood by and listened to you talking about that hole in the forest, that I grasped the true state of affairs.”