Peggy addressed half a dozen cards. Two, of course, went to Jess and Jimsy, another to Aunt Sallie Prescott; one to the captain of the Ruritania, and one other, which bore the address, "Eugene Mortlake, Esq."

It was a mischievous freak that made Peggy write this last missive, which read:

TO MR. EUGENE MORTLAKE,
Per Steamer Ruritania—in Mid-air:
Greetings from aeroplane Golden Butterfly.
R. & M. PRESCOTT.

That was all, but Peggy knew that it would serve its prankish purpose.

All this time the Silver Cobweb had been out at sea, but now, apparently detecting the maneuvers of the Golden Butterfly, she headed about, and came racing back. Peggy deftly attached weights—spare bolts from the tool locker—to each of the cards, and then, snatching up a megaphone, she hailed the uniformed figures on the bridge of the great vessel below them.

"Will you be good enough to mail some letters for us?"

"With pleasure!" came the reply in a big, bellowing British voice, from one of the stalwart figures beneath.

"All right; Roy, come down as low as you dare," cried Peggy, catching her bundle of "mail."

Roy threw over a couple of levers and turned a valve. Instantly the Golden Butterfly began to drop in long, beautiful arc. She shot by above the liner's bridge at a height of not more than fifteen feet. At the correct moment Peggy dropped the weighted bundle overboard, and had the satisfaction of seeing one of the officers catch it. The gallant officers, now realizing for the first time that a girl—and a pretty one—was one of the passengers of the big aeroplane, waved their hats and bowed profoundly.

"At the correct moment Peggy dropped the weighted bundle overboard."

And Peggy—what would Aunt Sallie have said!--Peggy blew them a kiss. But then, as she told Jess later:

"I was in an aeroplane, my dear—a sort of an unattainable possibility, in fact."

In the meantime, Mortlake, in the Silver Cobweb, had been duly mystified as to what the Golden Butterfly was about when she swooped downward on the steamer. For one instant the thought flashed across him that they were disabled. An unholy glee filled him at the thought. If only the Golden Butterfly were to come to grief right under Lieut. Bradbury's eyes, it would be a great feather in the cap of the Mortlake-Harding machine.

But, to his chagrin, he saw them rise the next instant, as cleverly as ever. Lieut. Bradbury, who had been watching the maneuver of the Golden Butterfly, gave an admiring gasp, as he witnessed the daring feat.

"Good heavens!" he exclaimed, and the evident note of astonishment and appreciation in his tones did not tend to increase Mortlake's self-satisfaction.

"The pesky brats," he muttered to himself; "we've got to do something to put them out of the race. There isn't another American-built aeroplane that I fear except that bothersome kids' machine."

And there and then Mortlake began to hatch up a scheme that in the near future was to come very nearly proving disastrous to Peggy and Roy and their high hopes.

"Magnificently handled, don't you think so, Mortlake?" inquired the naval officer, the next instant.

"Yes, very clever," agreed Mortlake, far too smart to show his inward feelings, or to wear his heart upon his sleeve; "very neat. But I can do the same thing if you'd care to see it?"

The naval officer glanced at the puffy features of his companion and his thick, bull-like neck.

"No, thanks," he said. "I've got to be getting back. There's another type of machine I've got to look over out at Mineola. It is really necessary that I reach there as quickly as possible."

"Very well," said Mortlake, inwardly relieved, as he didn't much fancy duplicating Roy's feat, "we'll head straight on for the shore."

"If you please."

But what was the Golden Butterfly doing? As the steamer raced onward, that aerial wonder had swung in a spiral, and was now seemingly hovering about, awaiting the arrival of the Silver Cobweb.

As the two aeroplanes drew abreast, Mortlake muttered something, and bent over his engines. The Cobweb leaped forward like an unleashed greyhound. But the Golden Butterfly was close on her heels, and making almost as good time. Mortlake plunged his hands in among the machinery and readjusted the air valve of the carburetor. Another increase of speed resulted. The indicator crawled up to sixty-six, sixty-eight and then to seventy miles an hour.

"Pressing her a bit, aren't you?" asked the officer, as they seemed to hurtle through the air, so fast did they rush onward.

"Oh, no. She's built for speed," responded Mortlake, with a gratified grin; "she'll leave any such old lumber wagon as that Prescott machine miles behind her any day in the week."

This seemed to be true. The Golden Butterfly, making about sixty miles, was being rapidly left behind.

"I should think you'd be afraid of overheating your cylinders," volunteered the lieutenant.

Now, this was just what Mortlake was afraid of. But, as has been said, he was the sort of man who, in sporting parlance, was willing always "to take a chance" to beat any one he considered his rival. He was taking a desperate chance now. Under the artificial means he had used to increase the speed of his engines, the motor was "turning up" several hundred more revolutions a minute than she had been built for.

Now they shot above the strip of white beach, and, below them the pleasant meadow-lands and patches of verdant woods began to show once more.

All at once, the sign for which Mortlake had been watching so anxiously manifested itself. A tiny curl of smoke ascended from one of the cylinder-heads. A smell of blistering, burning paint was wafted back to the nostrils of Lieut. Bradbury.

"I thought so," he said; "overheating already. Better slow down, Mortlake."

Mortlake glanced back. The Golden Butterfly, much diminished in size now by the distance, still hung doggedly on his heels.

"I'll give her more air," he vouchsafed stubbornly, "that ought to cool her off a bit—that and advanced spark."

He manipulated the necessary levers, but before many minutes it became apparent that, if urged at that rate, the Silver Cobweb would never reach Sandy Beach without a break-down.

"Hadn't you better shut down a bit? That paint's blistering, as if the cylinders were red-hot."

Much as he disliked to interfere with the operation of the aeroplane, the young officer felt that it was necessary that some means should be taken to compel Mortlake to reduce speed. If the engine became so overheated that it stopped in mid-air, they might be caught in a nasty position, where it might be impossible to volplane—or glide—downward, without the aid of the engine.

"It's all right, I tell you," said Mortlake stubbornly. "We'll beat those cubs into Sandy Beach, or——"

Or what, was destined never to be known, for at that instant, with a splutter and a sigh, the overheated engines, almost at a red-heat, stopped short. The propeller ceased to revolve, and the aeroplane began to plunge downward with fearful velocity.

But Mortlake, no matter what his other faults, possessed a cool head. The instant he lost control of the motor, he seized the warping levers, and began manipulating them. At the same time he set the rudder so as to bring the Silver Cobweb to earth in a series of long spirals. The maneuver was that of volplaning, and has been performed successfully by several aviators whose engines have suddenly ceased to work while in mid-air. The young officer watched approvingly. Whatever else Mortlake might be—and Lieut. Bradbury had not taken a violent fancy to him—he was a master of the aerial craft.

Despite the mishap to the engine—caused by his own carelessness—Mortlake managed to bring the Silver Cobweb to a gentle landing in a broad, flat meadow, inhabited by some spotted cows, which fled in undignified panic as the monster, silent now, swooped down like a bolt from the blue.

The instant the Silver Cobweb came to rest Mortlake's restless eyes glanced upward. He was hoping against all common sense that the young Prescotts had not seen his mishap, or at least that they would pass on above him unnoticing. His first glance showed him the Golden Butterfly still steadily plugging along, and a moment later it became apparent that they had seen the sudden descent of the Cobweb, for the aeroplane was seen to dip and glide lower, much as a mousing hawk can be seen to do.

"Hard luck," murmured the young naval officer, as Mortlake, who had clambered out of the machine, stamped and fumed by its side. Inwardly Lieut. Bradbury was thinking how stubborn men invariably meet with some mishap or accident.

"Yes, beastly hard luck," agreed Mortlake readily. "I see a farm-house over there, though, the other side of those trees. I guess I can get a bucket and some water over there. Once I've cooled those cylinders off, we'll be all right."

"How long will that take, do you think?" inquired the officer, pulling out his watch and a time-table.

"Not more than half an hour. It shouldn't take that."

"That means I miss my train. If we don't get into Sandy Beach by eleven o'clock, I can't possibly make it. And there's not another from there for two hours. That would make me late for my appointment at Mineola."

Mortlake's face fell. Here was a bit of hard luck with a vengeance. It might cost him a place in the contests.

"We can make up time, once we get under way," he said tentatively.

"That isn't it. I daren't risk it. I wonder if I can get an automobile or some sort of a conveyance about here."

"Not a chance. I know this neighborhood. It is very sparsely settled."

A sudden whir above them caused them both to look up. It was the Golden Butterfly, swooping and hovering above the disabled Cobweb.

"Had an accident?" shouted down Roy.

"What do you think? You can see we're not flying, can't you?" bellowed Mortlake, his face crimson with anger and mortification.

"Can we do anything to help you?" came from Peggy, ignoring the fellow's insulting tones.

"No!"

"Yes!"

The first monosyllable came from Mortlake. The second from Lieut. Bradbury.

"If you don't mind accepting a passenger, I should be glad of a lift to Sandy Beach. I've got to make a train," explained the young officer.

In five minutes the Golden Butterfly was on the sward beside the crippled Cobweb. Mortlake's face was black as night. He fulminated maledictions on the young aviators who had appeared at—for him—such an inopportune moment.

"Can I help you fix the machine?" asked Roy pleasantly. "There's nothing serious the matter, is there?"

"Not a thing," asserted Mortlake. "It's all the fault of the men who made the carburetor. They did a bungling bit of work, and the cylinders have overheated."

"Can we leave a message for you at your shops, or would you like a lift home with us?" asked Roy, who felt a kind of pity for the angry and stranded man.

"You can't do anything for me except leave me alone," snapped out Mortlake; "you cubs are altogether too inquisitive. You're too nosy."

"But not to the extent of making sketches and notes, Mr. Mortlake?" inquired Peggy sweetly—"cattily," she said it was, afterward.

Mortlake started and paled. Then, without vouchsafing a reply, he strode off in the direction of the farm house to get the water he needed.

"Now, Mr. Bradbury," said Roy, extending a hand.

The young officer leaped nimbly into the chassis, and presently a buzzing whir told that the faithful Golden Butterfly was taking the air once more.

"Score two for us!" thought Peggy to herself.

From a far corner of the pasture, Mortlake watched his young rivals climbing the sky. He shook his fist at them and his heavy face darkened.