HARVEY asked in a muffled voice: “May I take away my handkerchief?”

“It can do no harm, but I don’t know that your precaution did any good.”

“I kept my eyes open and peeped over the top; the way the Professor studied us proved he had misgivings, but he did not see my features.”

“It looks as if he is not satisfied.”

The elder referred to the fact that the aviator, instead of veering to the left and coming to a stop as he had done earlier in the day, continued his straightaway course. Harvey unshipped his field glass and leveled it at the object which rapidly grew smaller and finally flickered from sight.

“He is doing that to mislead us,” said Harvey.

“Is there any way by which we can make him believe he has succeeded?”

“How would it do to stop paddling and begin fishing if he comes into sight again?”

“I am proud of a brother bright enough to think of that; it is a good plan, for if he is not satisfied he will come back for another view and he mustn’t catch us napping.”

Accordingly the paddle was swung again, and the younger brother gave his attention to watching the sky in every direction, for it was possible that with so swift a machine as was at his command the Professor might make a wide circuit and swoop down upon them again from the rear.

“If he does,” said Harvey, “it will show that he doesn’t like the look of things, and if I resort to my handkerchief again he will know why I do so.”

“Which will be as bad as if you didn’t do it. If we can reach the end of the lake before he returns we’ll begin our hunt without more delay, but—”

“By George! Yonder he comes!”

“Quick! Get out your fishing line; I always carry mine.”

Dick dropped the paddle in the bottom of the canoe and in a twinkling had flung the sinker into the crystalline water. It took Harvey a little longer, but he did it, with a number of seconds to spare. They could well affect not to be aware of the aerocar, though it was sailing low down, since it moved silently, and true fishermen are always absorbed in the work, or rather pleasure, of trying to woo a bite from the finny inhabitants below the surface. Neither seemed to look up, but none the less they kept a stealthy watch for the monoplane in which they were interested.

Professor Morgan gave a thrilling exhibition of his machine’s capability and his skill in handling it. He made a sweeping curve which took him past the fishermen, swooping gracefully to the right and to the left at a height of less than a hundred feet. When he was nearest them he shouted:

“Hello, there! What are you doing?”

Harvey Hamilton just then was excitedly pulling at his line as if he had a bite and was more anxious to land his catch than to do anything else. Dick suspended his occupation and looked up.

“Can’t you see we are fishing?” was his fitting reply in the form of a question.

“You are watching me,” insisted the aviator, as he made another circle and came nearer.

“What do we care about you? You are scaring away the fish; I wish you would clear out and leave us alone.”

“Who is that with you?”

“Bill Jones, from Squedunk; he hasn’t much sense and if you don’t look out he’ll take a shot at you with his revolver, and if he doesn’t I will!”

And Dick dropped his fishing line over the edge of the canoe, picked up his rifle and pointed it at the loony inventor.

“Get!” he commanded, “before I fire!”

The demonstration was unexpected, and scared Professor Morgan. Had it not been done at the psychological moment, it is likely he would have approached still closer and forced Harvey to disclose himself. The youth was in a tremor, but it was hard for him to restrain his merriment over the rank bluffing of his brother. The Professor yanked his levers and with his feet abruptly turned the rudder so that his machine shot off at a tangent at an amazing rate of speed. Instead of turning back over his course, he made for the wooded, rocky, mountainous country which had been his destination when he believed he was not under the eye of any one. As soon as he was beyond distinct vision, Harvey dropped his fishing line and brought his field glass into use.

“Keep an eye on him as long as he’s in sight,” warned Dick, who also laid his line aside and turned to watch the aviator. The latter held to a direct course for half a mile or more, by which time he was above the section where the brothers believed Bohunkus Johnson was kept in confinement.

“He seems to have stopped,” said Dick.

“He has; he is descending.”Holding his machine in poise for a minute or two, Harvey saw it dropping down like a weight suspended at the end of a rope. It disappeared behind a mass of rocks and amid a group of large trees covered with exuberant foliage.

“It looks as if that is the spot for which we are hunting,” said Harvey lowering the glass.

“All the same it isn’t; it’s a trick meant to make us believe it is. Professor Morgan may be crazy regarding aeroplanes, but he isn’t in a good many other things. It has become a game of hide and seek between us.”

Conceding this to be the truth, our young friends had to decide upon their next step.

“If we land and go to the place, he will know we are more interested in him than he thinks we ought to be. He is watching us from where he landed.”

“And if we go there we shall not find Bunk. I do not think he is anywhere near. Meanwhile, the best thing we can do is to keep on fishing. Doubtless he has a glass and is scrutinizing us like a cat watching a mouse. Let’s drop our lines into the water.”

They did so and a minute later Harvey felt a tug at his hook. Drawing in his line, he landed a plump bass that must have weighed nearly two pounds.“If the Professor has noticed that,” remarked the younger, “it will help him to believe we are no more than we pretend to be; but, Dick, I don’t understand why he doesn’t shut us off from interfering with him.”

“How would he do it?”

“Pick up Bunk and carry him away.”

“Where to?”

“He could keep him in his workshop for the little while that must pass before he starts on his grand flight.”

“The Professor is shrewd enough to know the risk he will run. He took him away from that place because he was afraid Bunk would give him the slip. It would require too much of the Professor’s time to watch Bunk and hold him under his thumb. Besides, what is to prevent our hurrying to Dawson or some other nearby town and securing a writ of habeas corpus from a judge which would require the Professor to produce the body of Bunk in court and explain why he is held in durance,—I believe that’s the way they put it. Such a proceeding would not only be highly unpleasant to the Professor but would be followed by more unpleasant ones,—such as a lunacy commission to look into his own affairs. The aerial trip across the Atlantic would be knocked higher than Gilderoy’s kite.”

“If he is afraid to keep Bunk in his workshop, he can take him to any one of a score of places where he would be as well hidden as now.”

“That is what I’m afraid of. It seems to me we played our parts so well that very little suspicion is left in the Professor’s mind. Were it otherwise he would shift Bunk’s temporary home, though it isn’t likely he can hit at once upon one that is as satisfactory.”

“Then for the present we must continue to be fishermen.”

“So it strikes me, and if he is observing us closely he will admit that we are giving a very good imitation of fishermen,” added Dick as he drew in a bass almost as large as his brother’s. “You are facing the spot where you last saw him; give that as much attention as you do your line.”

Thus the situation remained for more than half an hour, during which two more fish were landed. It irked the brothers thus to sit idle, with the soft summer afternoon slipping past and the minutes going by unimproved. When they left camp it was with high hopes of bringing Bunk back before nightfall, but the prospect looked doubtful.

Suddenly Harvey saw a peculiar flickering agitation behind the rocks where the monoplane had disappeared.

“Something’s up!” he whispered, letting his line fall and bringing his glass again into play. “The Professor is bestirring himself.”

First the widespread wings of the monoplane rose slowly into sight; the powerful engine, slender body and rudders at the rear following. The uplifter was doing duty and the Dragon of the Skies climbed the aerial stairway smoothly and silently.

“See whether he has Bunk with him,” cautioned Dick, looking keenly in the same direction; “that’s the important point.”

“By George! he has!” exclaimed Harvey; “I see him plainly!”

“Let me have a look!”

Harvey passed the instrument to his brother, who hastily leveled it at the machine. “You can’t miss him,” added the younger; “he is sitting in his old place on the seat beside the Professor, who is so tall that his head rises far over Bunk’s.”

Dick was silent for a brief while. Suddenly he lowered the glass with a laughing exclamation.

“Ah, but the Professor is sly. I see the form behind him as you have described, but it isn’t Bohunkus Johnson!”“What do you mean?” asked the amazed Harvey.

“Study it out for yourself,” replied the other, handing over the instrument.

A few seconds’ scrutiny was enough. That which Harvey had taken for their colored friend was a cunningly arranged dummy which might well deceive a spectator. Professor Morgan had adjusted a coat and other garments so as to resemble the form of the negro and make the mistake almost certain. But for the keener shrewdness of his brother, Harvey would have been deceived.

“I see what you mean, Dick; I hadn’t the first suspicion of such a trick.”

“We are not dealing with a fool when we butt against the Professor.”

“He keeps going toward Purvis,” said Dick, who had once more resorted to his field glass; “he seems to be certain he has misled us.”

“Why shouldn’t he be? His last view showed him we were fishing as hard as ever and he must believe we shall not figure any more in his affairs.”

“Well, Dick, we must be up and doing if we expect to help Bunk.”

“True; we are through fishing for the present.”They flung the lines down in the boat, Dick took up the paddle.

“If we have to camp out to-night, we shall have our supper with us. There’s some consolation in that. I don’t believe the Professor will show up again before to-morrow morning. He may have his invention completed by that time, but everything must remain guesswork for awhile.”

Under the propulsion of the paddle the light craft skimmed swiftly over the placid lake. Dick put forth all his skill and the canoe touched the shingle a few minutes later and both stepped ashore and drew the boat up the shore.

“It strikes me, Harv, that it will be better for us to separate. We don’t know whether to hunt for Bunk at the place where the Professor halted awhile ago, or to look for him farther over to the right where I have seen his machine several times.”

“I should say that the spot you saw is most likely the right one.”

“So it seems to me, but the afternoon is so far gone that we shall need every minute and we mustn’t go too far astray. It’s a safe guess that one of us will establish communication with Bunk pretty soon.”

Further discussion made it seem that the section selected by Dick was about a fourth of a mile to the east of the other. Thus it would not become necessary for them to lose mutual touch. Like all boys accustomed to hunt and wander together in the woods, they had a system of signaling by means of whistling. Bunk was also familiar with the code. The three had made their wishes known when a mile apart.

“If you find him,” said Dick, “whistle three times and I’ll do the same if I succeed.”

“Suppose both fail?”

“When it becomes too dark to hunt longer, I’ll call to you; you will answer in our usual way and each will tramp toward the other. Then we’ll make camp and start in again at daybreak.”

It was agreed that in case either met the Professor or ran into danger and needed help, he would summon it by five or six short sharp blasts from his lips.

“You have your rifle and I only my revolver, so I shall be more likely to need you,” said Harvey as the brothers parted company.