RESCUED.

All those on the Christina were astounded at the move made by the two boys.

"Leave 'em in the water for a while!" shouted Brady, Sr. "I guess that'll take the ginger out of 'em. Don't be in any hurry, captain, about turning around."

The captain could not have turned very quickly, even if he had wanted to. With all sail set, the Christina was driving through the water at race-horse speed. It would take time, and she would inevitably have to get a long way from the boys before she could be put about.

Both Carl and Ferral were good swimmers and had little difficulty in keeping themselves afloat, hampered though they were with their wet clothing.

"We're in for it now, Carl!" gurgled Ferral. "That sailboat will put about and we'll be hauled aboard—then that swab of a Brady will have us just where he wants us." Ferral rose in the water, shook his head to clear his eyes, and peered after the Christina. "They're coming around now," he added.

"Led dem come aroundt all vat dey blease," sputtered Carl; "Matt vill pull us oudt oof der vet pefore dey ged here."

"Matt?" echoed Ferral.

"Look oferheadt vonce, Tick."

Ferral took a look upward. Rushing toward that part of the lake and swooping downward like a huge bird was an air ship. The strange craft was almost upon him and Carl. Two men were leaning over the guard rail of the car on each side; both held coiled ropes in their hands, and one of them was shouting instructions to Matt, who was in charge of the motor.

The Christina was forging along on the back track, the Bradys well forward and clinging to ropes while they watched the manoeuvres of the Hawk. It must have been apparent to them that the Hawk would pick up the boys before the Christina could come anywhere near them.

Splash! splash!

Two ropes dropped in the water just as the Hawk, with a graceful, gliding motion, came to an even keel some fifteen or twenty feet above the surface of the lake. The whirling propeller lessened its speed and the air ship hovered over the water.

"Grab the ropes!" shouted a voice from the Hawk's car.

It was a useless suggestion, for the ropes had already been caught.

"Can you climb up?" called one of the men. "It isn't safe to bring the air ship any closer to the water."

Climbing the rope was easy for Ferral. Hand over hand he lifted himself upward, was caught by the man and pulled over the rail and into the car. But Carl was no sailor, and every time he tried to climb the rope he slid back into the water again.

"Hang hard," shouted the man in the car, "and we'll pull you up."

The Christina, by then, was quite close. Carl had hardly been lifted clear of the water before the crack of a revolver rang out.

Brady, Jr., had passed his own revolver to his father, and the latter was pecking away at Carl as he gyrated under the car of the air ship.

"Keep a firm hold on that rope!" cried the man in the car. "We've got to ascend and get away from that sailboat."

The nose of the Hawk tilted sharply upward, the propeller whirred at steadily increasing speed, and the air ship bore swiftly away with the dripping form of the Dutch boy swinging underneath.

Crack! crack! came the reports from Brady's revolver.

Carl, however, was not a good target, and, besides, Brady had to fire from the pitching deck of the Christina. All the bullets flew wide, and before Brady could fire more than three shots the air ship was out of range.

The Dutch boy's position was in no wise comfortable for his nerves. The Hawk was steadily mounting toward the clouds, and Carl was swaying underneath like a pendulum. As soon as the air ship was out of pistol range of the Christina, however, hands were again laid on the rope and Carl was jerked up to the car and pulled to safety.

"Well, great spark plugs!" cried the voice of Motor Matt. "Of all the brain twisters I ever ran up against, this takes the banner! Where did you come from, Dick? And how does it happen Carl is with you?"

Matt was in a chair at one end of the open space in the middle of the car, his hands on the levers that worked the mechanism and controlled the motor.

Ferral, wet as a drowned rat, was sitting up on the floor of the car, his back against the rail. Across from him was Carl. In the other end of the car were the other two passengers. One of these wore the uniform of a policeman.

Ferral's novel situation filled him with wonder. His eyes were darting all around him, above at the swelling gas bag, around him at the machinery, the propeller, the rudder and space, and below him at the heaving expanse of water.

"Well, strike me lucky," he breathed, "but all this seems like a dream. Am I doing a caulk, and imagining I'm wide awake? If I am, pinch me, somebody."

"You're not asleep, old chap," laughed Matt, "if that's what you mean by 'doing a caulk.' Where did you come from?"

"Denver. I'm on my way to Quebec. Heard you were anchored in Chicago and stopped off there to see you. Couldn't find you at home, but I did find Carl."

"How in the world did you and Carl happen to be on that sailboat?" went on Matt. "And why did you jump overboard?"

"Carl pulled me overboard," replied Ferral.

"It vas healthier for us in der vater dan it vas on der poat," put in Carl, slapping at his wet clothes. "Aber I vouldn't haf pulled Verral oferboardt oof I hatn't seen der Hawk skyhootin' along toward us. Ach, dot vas pully! How you habben to be vere you vas schust ven ve needet you, bard?"

"Mr. Jameson"—and Matt nodded toward the passenger forward with the officer—"is thinking of buying the Hawk, but he wanted to try her out with a good long flight and to see if she would be perfectly safe over water. So we sailed over Chicago and headed into the lake. We saw that sailboat, but didn't pay much attention to her until Harris saw some one waving something on her deck. Then, thinking we were being hailed, we laid a course for her. As we came closer, we saw two persons jump into the water. That was our cue to get closer to the lake and pick you up. But what was the matter on that boat? You haven't told me yet."

Ferral ran one hand into the front of his shirt and fished out his water-soaked roll of greenbacks.

"That's what caused the trouble," said he. "Brady wanted the money."

"Brady?" Motor Matt looked questioningly at Carl.

"Yah, so," spoke up Carl. "It iss der same Prady vat you hat sooch a time mit, ofer py Villoughpy's svamp."

"What do you think of that, Harris?" cried Matt, looking at the officer.

"If Brady is on that boat," returned Harris, showing a good deal of excitement, "we ought to tip somebody off and have him captured."

"We'll turn back toward Chicago," said Matt. "Meantime, Carl, you and Dick tell us all about how you got into that fix. Hurry up with the yarn. If we're to do anything toward capturing Brady, we haven't much time to lose."

Carl and Ferral went over their recent experiences. Matt's wonder grew as he listened. It was strange the way events had fallen out and brought the three chums together just in time to avert a robbery—perhaps a tragedy.

"It's main queer, mate, don't you think?" queried Ferral, when the details had all been given.

"Queerest thing I ever heard of!" avowed Harris. "I knew Brady had a son, but I hadn't a notion where he was, or what he was doing. Looks as though young Brady was a chip off the old block."

"It's a lesson for me," remarked Ferral ruefully, "never to pick up a fellow on his own showing. The queerest part of the whole business was my meeting young Brady on the train, walking right into the trap he had set for me and his father was going to help him spring, and towing Carl along."

"We're coming close to the shore, King," called Jameson.

Matt stole a look over the side.

"Take out your notebook and pencil, Harris," said he, drawing back, "and write a note. Address the memorandum to the police department and say that Hector Brady and his son are off the government pier in a sailboat called the Christina, and that if the scoundrels are captured, a tug better put off at once."

Harris scribbled the note. When it was finished, Matt had him tie the small sheet of paper around a bolt taken from the tool box.

"We'll fly low over the park near the Art building," said Matt, "and you yell to the first policeman you see, Harris, and drop the note."

There was no need of yelling to attract anybody's attention in the park, for every person was looking upward at the air ship.

Harris was not long in sighting an officer, and his own uniform demanded the officer's respectful attention.

The note was dropped, and those in the air ship could see the policeman pick it up, untie the sheet of paper and read the communication.

Before the Hawk got out of sight of the park, Matt and the rest had the satisfaction of seeing the policeman wave his hand to signify that he understood, and then hurry off toward the lake.

"I guess that will cook Brady's goose for him," muttered Harris complacently.

"Are you satisfied with the Hawk, Mr. Jameson?" inquired Matt.

"I never imagined that an air ship had been invented which could be manoeuvred as you have manoeuvred this one," said Jameson. "I'm so well satisfied with the Hawk that I will give three thousand for her."

Carl gave a gasp and stared at Ferral, only to find that Ferral was already looking at him.

Were Matt and Ferral to lose the air ship, after all?