plane."

"Say, did you happen to notice that car on the road over there?" asked
Larry.

"I saw one moving along in a cloud of dust; but didn't notice who was in it. Why do you ask that?" answered the young aviator, looking at his friend curiously.

"Oh well, it happened to be those same two men you saw, when you brought little Tommy ashore," remarked the other, mysteriously.

"But I thought they were headed for Bloomsbury?" exclaimed Andy.

"That's what they said; but you see they thought it worth while to run past and come away out here, just to take a peek over the fence and see what you Bird boys had in this section."

"That's funny now," muttered Andy, who, being less keen than his cousin, could not let suspicion find lodgment in his brain as quickly either. "But perhaps Frank may know who they are. He keeps pretty well posted on everybody connected with aviation meets and inventions. Marsh, he said his name was; what was the other, do you know, fellows?"

"I heard him call the man at the wheel Longley several times, so I reckon that must be his handle," said Elephant, who never liked being left out in the cold whenever there was an argument on the carpet, or in fact any talking being done.

Frank came sailing directly toward them with considerable speed. When it began to look as though he might mean to collide with the low workshop close by, he suddenly swooped upward, and passed over their heads, uttering a laugh as he saw how the alarmed Elephant dropped flat on his face and hugged the earth.

Circling around, Frank cut several fancy figures with the new biplane, the hum of the twin propellers making merry music in the ears of the delighted boys.

Finally, as though tiring of this sport he dropped on the grass as lightly as he had a little while before nestled on the smooth surface of Sunrise Lake.

The three boys joined him, and willing hands soon stored the aeroplane in the snug hangar prepared for it alongside the workshop. Then Andy dodged inside to change his clothes before he got a chill; for though summer had come, the air was far from hot right then by any means, a storm having cleared the atmosphere during the preceding night, and leaving it delightfully crisp.

"I saw a car buzzing along the road while I was up, but couldn't use my glass to see who was in it. Did you notice, Larry?" Frank asked as they stood there near the open door of the shop.

"I was just going to mention the fact that those two men act like they had taken a great fancy to you and Andy," returned the other, readily.

Frank Bird frowned.

"H'm! I just don't like to hear that," he said. "Andy and myself have been working on something lately that we want to keep a dead secret from everybody. If we don't tell even our friends, then there can be little chance of a leak. But I'm not inviting strangers to take a ride with me, or visit us in our shop. Though you can come in now, any time you want, Larry and Elephant."

"Sho! we wouldn't know the wing feather of a plane from one that belonged in the tail or steering rudder," chuckled Larry.

"But I'm meaning to learn, Frank," put in the small chap, strenuously. "It looks so easy for you fellows, knocking around up there, with nobody ever getting in your way, like on our roads, that I want to fly."

"Well," pursued Frank, shaking his head. "I don't encourage anybody to take up the business. It's certainly the most dangerous calling going at present; but after the Wrights have put their latest balancing idea into general use, the number of dead aviators will drop fast. In time it may be a fellow can hardly fall out of a well-made flying machine if he is the most reckless aviator going."

"Hear that, Elephant," laughed Larry. "Hope yet that some of us common truck may be flapping through the upper currents, and getting out of the wet when it rains, by sailing above the clouds. But I see some fellow coming along the road on his wheel like he had a hurry call. Looks like Nat Holmes too, and he's coming in here."

"Funny how badly balanced that fellow is," remarked Frank. "Always in a hurry in everything he tackles; and then falling all over himself when he tries to talk. He's waving his hat too like he had something interesting to say. Let's hope, boys, it happens to be one of his good hours; or we're in for a lot of gibberish Hottentot patter, I'm afraid."

CHAPTER IV

SUSPICION

"F-f-frank!" stammered the new arrival, as he actually fell off his wheel, allowing the same to drop in a heap on the turf.

"That's me; what d'ye want, Nat?" asked the one addressed; as he assumed a reassuring air, knowing what a terrible mess the wretched stutterer often made of his attempt at speech, especially when he happened to be excited.

Nat was breathing hard. He always did things with a whirlwind method; and of course the exertion added to his difficulty in forming such words as he wanted.

"D-d-did y-y-you k-k-k-," he started, with a rush; and then seemed to lose his grip entirely; for all he could do was to make a sharp, hissing sound, get red in the face under the strain and tremble all over.

"I s-s-say, d-d-do y-y-y-," he went on, when there came another full stop, and as Larry said, a further escape of gas to account for that hissing noise from between his partly closed lips.

The contortions of his face when poor Nat worked himself into this sort of a fever were simply agonizing. Some boys made it a habit of laughing coarsely at the afflicted boy. But Frank always felt sorry, and tried the best he knew how to break the spell that seemed to bind up Nat's vocal faculties. For strange to say, there were other times when Nat could really speak calmly and evenly, as if he had never stammered in his life.

As though utterly despairing of ever being able to get out what he so eagerly wished to say, the boy suddenly snatched a pencil from one pocket, and a pad of paper from another. These necessities he always carried along with him, though hating to have to make use of such a silly trick at all.

Rapidly dashing a line or so upon the little pad, Nat tore the sheet off, and thrust it into Frank's hand.

Andy had come out of the shop by that time, dressed in dry garments; and bending over his cousin's shoulder he read these words:

"Percy's new aeroplane has arrived at the station. He's down there right now, seeing about having it put on a cart and pulled to his shack."

"Just about what we expected; eh, Frank?" asked Andy, handing the scrap of paper to Larry, so that he and the runt could read what news Nat had brought in such a tremendous hurry.

It was as if the stammering boy had judged, that of all the people in Bloomsbury who would be interested in knowing that Percy had received a new aeroplane, the Bird boys took front rank. For was not Percy Carberry the old-time rival of Frank; and on numerous occasions had he not striven furiously to keep the cousins from winning the laurels that came their way, despite all opposition?

"Yes, I understand that he was going in for aviation again," replied the other. "And I don't know whether I'm glad or sorry. If Percy and that crony of his, Sandy Hollingshead, only believed in the square deal, we might have great times in racing and exploring; but the trouble is, they hate to see anybody getting ahead of them, and lots of times as everybody understands, have tried to injure our machine."

"Oh! I don't know,"