But none were needed. So stunned were the foreigners by the lightning bolt, which had miraculously pa.s.sed our friends, and so unnerved by the striking down of La Foy, their leader, that they seemed like men half asleep. Before they could offer any resistance they were bound with the same ropes that had held our friends in bondage. That is, all but the big Frenchman himself. He seemed beyond the need of binding.

Mound, the engineer, and his a.s.sistant, came hurrying in from the motor-room, followed by Koku.

"We found him chained up," Jerry explained, as the big giant, freed from his captivity, rubbed his chafed wrists.

"Are there any of the foreigners back there?'

"Only those two knocked out by the lightning," the engineer explained.

"We've made them secure. I see you've got things here in shape."

"Yes," replied Tom. "And now to see where we are, and to get back home.

Whew! But this has been a time! Koku, what happened to you?"

"They no let anything happen. I be in chains all the while," the giant answered. "Jump on me before I can do anything!"

"Well, you're out, now, and I think we'll have you stand guard over these men. The tables are turned, Koku."

The bound ones were carried to the same prison whence our friends had escaped, but their bonds were not taken off, and Koku was put in the place with them. By this time La Foy and the two other stricken men showed signs of returning life. They had only been stunned.

The young inventor and his friends, once more in possession of their airship, lost little time in planning to return. They found that the spies were all expert aeronauts, and had kept a careful chart of their location. They were then halfway across the Atlantic, and in a short time longer would probably have been in some foreign country. But Tom turned the Mars about.

The craft had only been slightly damaged by the lightning bolt, though three of the gas bag compartments were torn, The others sufficed, however, to make the ship sufficiently buoyant.

When morning came Tom and his friends had matters running almost as smoothly as before their capture.

The prisoners had no chance to escape, and, indeed, they seemed to have been broken in spirit. La Foy was no longer the insolent, mocking Frenchman that he had been, and the two chief foreign engineers seemed to have lost some of their reason when the lightning struck them.

"But it was a mighty lucky and narrow escape for us," said Ned, as he and Tom sat in the pilot-house the second day of the return trip.

"That's right," agreed his chum.

Once again they were above the earth, and, desiring to get rid as soon as possible of the presence of the spies, a landing was made near New York City, and the government authorities communicated with. Captain Warner and Lieutenant Marbury took charge of the prisoners, with some Secret Service men, and the foreigners were soon safely locked up.

"And now what are you going to do, Tom?" asked Ned, when, once more, they had the airship to themselves.

"I'm going back to Shopton, fix up the gas bag, and give her another government trial," was the answer.

And, in due time, this was done. Tom added some improvements to the aircraft, making it better than ever, and when she was given the test required by the government, she was an unqualified success, and the rights to the Mars were purchased for a large sum. In sailing, and in the matter of guns and bombs, Tom's craft answered every test.

"So you see I was right, after all, Dad," the young inventor said, when informed that he had succeeded. "We can shoot off even bigger guns than I thought from the deck of the Mars."

"Yes, Tom," replied the aged inventor, "I admit I was wrong."

Tom's aerial warship was even a bigger success than he had dared to hope. Once the government men fully understood how to run it, in which Tom played a prominent part in giving instructions, they put the Mars to a severe test. She was taken out over the ocean, and her guns trained on an obsolete battleship. Her bombs and projectiles blew the craft to pieces.

"The Mars will be the naval terror of the seas in any future war,"

predicted Captain Warner.

The Secret Service men succeeded in unearthing all the details of the plot against Tom. His life, at times, had been in danger, but at the last minute the man detailed to harm him lost his nerve.

It was Tom's enemies who had set on fire the red shed, and who later tried to destroy the ship by putting a corrosive acid in one of the propellers. That plot, though, was not wholly successful. Then came the time when one of the spies hid on board, and dropped the copper bar on the motor, short-circuiting it. But for the storage-battery that scheme might have wrought fearful damage. The spy who had stowed himself away on the craft escaped at night by the connivance of one of Tom's corrupt employees.

The foreign spies were tried and found guilty, receiving merited punishment. Of course the governments to which they belonged disclaimed any part in the seizure of Tom's aerial warship.

It came out at the trial that one of Tom's most trusted employees had proved a traitor, and had the night before the test, allowed the foreign spies to secrete themselves on board, to rush out at an opportune time to overpower our hero and his friends. But luck was with Tom at the end.

"Well, what are you going to tackle next, Tom?" asked Ned, one day about a month after these exciting experiences.

"I don't know," was the slow answer. "I think a self-swinging hammock, under an apple tree, with a never-emptying pitcher of ice-cold lemonade would be about the thing."

"Good, Tom! And, if you'll invent that, I'll share it with you."

"Well, come on, let's begin now," laughed Tom. "I need a vacation, anyhow."

But it is very much to be doubted if Tom Swift, even on a vacation, could refrain from trying to invent something, either in the line of airships, water, or land craft. And so, until he again comes to the front with something new, we will take leave of him.

THE TOM SWIFT SERIES

By VICTOR APPLETON

These spirited tales convey in a realistic way, the wonderful advances in land and sea locomotion. Stories like these are impressed upon the memory and their reading is productive only of good.

TOM SWIFT AND HIS MOTOR CYCLE

TOM SWIFT AND HIS MOTOR BOAT

TOM SWIFT AND HIS AIRSHIP

TOM SWIFT AND HIS SUBMARINE BOAT

TOM SWIFT AND HIS ELECTRIC RUNABOUT

TOM SWIFT AND HIS WIRELESS MESSAGE

TOM SWIFT AMONG THE DIAMOND MAKERS

TOM SWIFT IN THE CAVES OF ICE

TOM SWIFT AND HIS SKY RACER

TOM SWIFT AND HIS ELECTRIC RIFLE

TOM SWIFT IN THE CITY OF GOLD