and
the rattle of some many-jointed vehicle, with loose springs and
looser wheels.

"Eradicate Sampson!" exclaimed Tom. "But who would ever think that
the colored man's mule could get up such speed as that cloud of dust
indicates. His mule's feet must be working overtime, but he goes
backward about as often as he moves forward. That accounts for it.
There's lots of dust, but not much motion."

Once more, from the midst of the ball-like cloud of dirt came the
voice of the colored man:

"Now behave yo'se'f, Boomerang. We'm almost dere an' den yo' kin sit
down an' rest if yo' laik. Jest keep it up a little longer, an'
we'll gib Massa Tom his telephone. G'lang now, Boomerang."

The tattoo of hoofbeats was slowing up now, and the cloud of dust
was not so heavy. It was gradually blowing away. Tom Swift walked
down to the fence that separated the house, grounds and shops from
the road. As he got there the sounds of the mule's progress, and the
rattle of the wagon, suddenly ceased.

"G'lang! G'lang! Don't yo' dare t' stop now, when we am most dere!"
cried Eradicate Sampson. "Keep a-movin', Boomerang!"

"It's all right, Eradicate. I'm here," called Tom, and when the last
of the dust had blown away, the lad waved his hand to an aged
colored man, who sat upon the seat of perhaps the most dilapidated
wagon that was ever dignified by such a name. It was held together
with bits of wire, rope and strings, and each of the four wheels
leaned out at a different angle. It was drawn by a big mule, whose
bones seemed protruding through his skin, but that fact evidently
worried him but little, for now the animal was placidly sleeping,
while standing up, his long ears moving slowly to and fro.

"Am dat yo', Massa Tom?" asked Eradicate, ceasing his task of
jerking on the lines, to which operation the mule paid not the least
attention.

"Yes, I'm here, Rad," replied Tom, smiling. "I came out of my shop
to see what all the excitement was about. How did you ever get your
mule to make so much dust?"

"I done promise him an extra helpin' ob oats ef he make good time,"
said the colored man. "An' he done it, too. Did yo' see de dust we
made?"

"I sure did, but you didn't do much else. And you didn't make very
good time. I watched you, and you came along like an ice wagon after
a day's work on the Fourth of July. You were going fast, but moving
slow."

"I 'spects we was, Massa Tom," was the colored man's answer. "But
Boomerang done b