unced and the ground
shook as though from an earthquake.

A glaring light shone out from the ponderous moving body, and above the
roar and rattle a voice called:

"Out out of the way! We've lost control! Look out!"

"Bless my steering wheel!" gasped Mr. Damon, "that was Tom Swift's
voice! But what is he doing in that--thing?"

"It must be his new invention!" exclaimed Ned.

"What is it?" asked Mr. Nestor.

"A giant," ventured Ned. "It's a giant machine of some sort and--"

"And it's running away!" cried Mr. Damon, as he quickly steered his car
to one side--and not a moment too soon! An instant later in a cloud of
dust, and with a rumble and a roar as of a dozen express trains fused
into one, the runaway giant--of what nature they could only
guess--flashed and lumbered by, Tom Swift leaning from an opening in
the thick steel side, and shouting something to his friends.

Chapter XI

Tom's Tank

"What was it?" gasped Mary, and, to her surprise, she found herself
close to Ned, clutching his arm.

"I have an idea, but I'd rather let Tom tell you," he answered.

"But where's it going?" asked Mr. Nestor. "What in the world does Tom
Swift mean by inviting us out here to witness a test, and then nearly
running us down under a Juggernaut?"

"Oh, there must be some mistake, I'm sure," returned his daughter. "Tom
didn't intend this."

"But, bless my insurance policy, look at that thing go! What in the
world is it?" cried Mr. Damon.

The "thing" was certainly going. It had careened from the road, tilted
itself down into a ditch and gone on across the fields, lights shooting
from it in eccentric fashion.

"Maybe we'd better take after it," suggested Mr. Nestor. "If Tom is--"

"There, it's stopping!" cried Ned. "Come on!"

He sprang from the automobile, helped Mary to get out, and then the
two, followed by Mr. Damon and Mr. Nestor, made their way across the
fields toward the big object where it had come to a stop, the rumbling
and roaring ceasing.

Before the little party reached the strange machine--the "runaway
giant," as they dubbed it in their excitement--a bright light flashed
from it, a light that illuminated their path right up to the monster.
And in the glare of this light they saw Tom Swift stepping out through
a steel door in the side of the affair.

"Are you all right?" he called to his friends, as they approached.

"All right, as nearly as we can be when we've been almost scared to
dea