t. Take the wheel somebody!"

"Wouldn't it be better to turn about, and run before the wind, so as
not to put too great a strain on the machinery?" asked Lieutenant
Marbury.

"Perhaps," agreed Tom. "Hold her this way, though, until I see what's
wrong!"

Ned and the government man took the wheel, while Tom hurried along the
runway leading from the pilot-house to the machinery cabin. The gale
was still blowing fiercely.

The young inventor cast a hasty look about the interior of the place as
he entered. He sniffed the air suspiciously, and was aware of the odor
of burning insulation.

"What happened?" he asked, noting that already the principal motive
power was coming from the big storage battery. The shift had been made
automatically, when the main motor gave out.

"It's hard to say," was the answer of the chief engineer. "We were
running along all right, and we got your word to switch on more power,
after the turn. We did that all right, and she was running as smooth as
a sewing-machine, when, all of a sudden, she short-circuited, and the
storage battery cut in automatically."

"Think you put too heavy a load on the motor?" Tom asked.

"Couldn't have been that. The shunt box would have taken that up, and
the circuit-breaker would have worked, saving us a burn-out, and that's
what happened-a burn-out. The motor will have to be rewound."

"Well, no use trying to fight this gale with the storage battery," Tom
said, after a moment's thought. "We'll run before it. That's the
easiest way. Then we'll try to rise above the wind."

He sent the necessary message to the pilot-house. A moment later the
shift was made, and once more the Mars was scudding before the storm.
Then Tom gave his serious attention to what had happened in the engine
room.

As he bent over the burned-out motor, looking at the big shiny
connections, he saw something that startled him. With a quick motion
Tom Swift picked up a bar of copper. It was hot to the touch--so hot
that he dropped it with a cry of pain, though he had let go so quickly
that the burn was only momentary.

"What's the matter?" asked Jerry Mound, Tom's engineer.

"Matter!" cried Tom. "A whole lot is the matter! That copper bar is
what made the short circuit. It's hot yet from the electric current.
How did it fall on the motor connections?"

The engine room force gathered about the young inventor. No one could
explain how the copper bar came to be where it was. Certainly n