The surprise in store for them was this. The swimmer was an old friend of theirs.

“Captain Sprowl!” shouted Jack, as they neared him.

“Aye! aye! my hearty!” came back the response, in the old New Englander’s hearty voice, “lay alongside and I’ll come aboard.”

“What, you know him!” demanded Ned.

“Do we? I should say so. He was in command of Professor Dinkelspeil’s yacht when the mutineers sunk her. After that he was with us all through that Amazon country I told you about.”

But it was no time to enter into explanations. The Electric Monarch was skillfully maneuvered alongside the doughty old mariner before the boats from the steamer had fairly left the vessel’s side. Tom, who had also recognized Captain Sprowl, ran forward from his post in the stern and threw him a line. Five minutes later they were all standing in the pilot-house listening to the captain’s story of how he had come to loosen his hold of the jack-staff and plunge into the sea.

“You see, my hearties,” he said, “I was sure it was you in this here sky-hooting, sea-scooting contraption and so I says to myself, ‘I’ll give ’em a proper salute, I will, ship-shape, man-o-war fashion.’”

“Well, you certainly did, Captain,” laughed Jack, “but what in the world were you doing on that ship?”

The captain looked knowing.

“I am on my way to Portstown, Maine,” he said. “There’s a big fair there next week and one of the features of it is to be an aerial carnival. I’m to be in charge of the airship part of it and I’ve booked some of the best aviators in the country.”

The boys looked interested. Anything to do with airships always appealed to them.

“It’s just come to me,” resumed the captain, “that maybe you’d like to bring this contraption up thar’ and try for some of the prizes. What do you say?”

It was characteristic of Captain Sprowl that, regardless of his wet clothes and recent narrow escape, he made no more of it than if everything was all right and he had come on board the Electric Monarch in quite the ordinary course of events.

“Well, you see, Captain, this ship, the Electric Monarch we call it, isn’t ours at all. It really belongs to Ned Nevins here.”

“That is, a share of it does,” spoke Ned modestly.

“Well, what does Ned say?” inquired the captain, as Heiny entered the pilot house with steaming hot coffee which Jack had ordered got ready as soon as they struck the water.

“Ned says—yes!” responded the lad, “but how about you, Jack and Tom?”

“So far as I’m concerned I think it would be a splendid thing,” said Jack. “It would give us a chance to try out the Electric Monarch in competition with other air craft, and then, too, the voyage up there would put her through her paces in great shape. My answer is—yes.”

“Same here,” declared Tom with positiveness.

“Ches, dot suids me,” said Heiny, balancing his tray like a born waiter while the captain gulped down his steaming coffee.

“Then we’ll call it settled,” said the captain. “I’ll send you entry blanks on my arrival at Portstown. Be ready to start as soon as possible.”

“Don’t worry about that, Captain,” said Jack, “we certainly shall be ready.”

By this time the boats from the steamer had come alongside and the singular interview had to be concluded.

“Well, I think it is safe to say that a business deal was never conducted under more curious auspices than this one,” laughed Jack, as the captain prepared to board one of the boats. “I guess you’d be ready to talk business if you fell out of a balloon, Captain.”

“If there was an undertaker handy, I would,” said the captain. And with a cheerful wave of his hand, the stout old seaman stepped into a boat and was rowed back to the steamer.

As the vessel got under way again the Electric Monarch took to the air, rising as easily from the water as she had from the land. With parting cheers and mutual salutes the two craft parted, the steamer to resume her northward voyage, the Electric Monarch to turn homeward after an eventful trial trip which, so far as the boys could see, had been a success in every particular.

On the homeward voyage some brisk breezes were encountered, but the Electric Monarch behaved splendidly. A short distance outside the village of Enderby, Jack, who had surrendered the wheel to Ned, in order to initiate him into handling the craft that bore his name, spied a black dot in the distance.

It was high in the air and traveling rapidly toward them. It was some minutes before they made out what it was.

“A balloon!” They all made the discovery simultaneously. The big gas bag was traveling fast and on a course which would bring it across the Electric Monarch’s bows. As it came closer they saw that it was colored a brilliant red and bore on the sides of its gas bag in huge letters, “New Yorker.”

“Why, that’s one of the balloons that went up in that contest at New York,” cried Jack. “They started from Brooklyn last night. My! they’ve made good time.”

On came the balloon, driving fast. In it were two men clad in khaki and wearing close-fitting caps. They waved frantically to the lads in the Electric Monarch and the hydroaeroplane was brought close alongside the balloon, keeping up with it easily.

One of the men in the balloon basket snatched up a megaphone. Placing it to his lips, he shouted:

“Ahoy! what craft is that?”

“The Electric Monarch of Nestorville, Mass.,” rejoined Jack, in true air-sailor fashion. “What craft is that?”

“The New Yorker, of New York, pilots Augustus Yost and Alan Frawley, will you report us?”

“We sure will. When are you coming down?”

“We don’t know. This is an endurance race—we’ll keep up as long as possible. Good-bye.”

“Good-bye,” and so ended a scene which ten years ago would have been scoffed at as impossible, yet it was only the other day that newspaper readers perused the account of an aeroplane towing a disabled dirigible into her hangar.

But we must now hasten home to High Towers with the boys. They arrived there without further incident, having made excellent time. The workmen who had been left behind were there to help them make a landing, and once more the Electric Monarch rested on dry land.

Hardly had she touched the ground, however, before Jupe was seen running from the house at top speed. He was shouting something, but till he got close by they could not make out what it was. Then his words became clearer.

“It’s my father!” cried Jack, in an alarmed voice.

“What can be the matter?” cried Tom.

“I don’t know, but it must be something serious,” declared Jack, with a pale face, as Jupe came panting up.

“Oh, Massa Jack,” he wailed, “yo’ fadder am turrble sick, sah. Dey heard de bell ring an’ hurry up to der liberry. Dey foun’ him lyin’ on de flo’ widout his senses.”

“Gracious!” cried Jack, “we must hurry to the house at once.”

“An’—an’ dat ain’ de wustest,” stammered out Jupe.

“Well, what else?”

“De do’ ob de safe done be open an’ it look lak’ some papers bin done taken out!”