stood, and saw that they had made
notes of the pressure recorded on the recoil checks directly after the
guns were fired. Mr. Damon, blessing innumerable objects under his
breath, was looking over the side of the rail to discover the cause of
the commotion and cries of warning from below.

"I don't believe it was anything serious, Tom," said the odd man. "No
one seems to be hurt." "Look at Eradicate!" suddenly exclaimed Ned.

"And his mule! I guess that's what the trouble was, Tom!"

They looked to where the young bank employee pointed, and saw the old
colored man, seated on the seat of his ramshackle wagon, doing his best
to pull down to a walk the big galloping mule, which was dragging the
vehicle around in a circle.

"Whoa, dere!" Eradicate was shouting, as he pulled on the lines. "Whoa,
dere! Dat's jest laik yo', Boomerang, t' run when dere ain't no call
fo' it, nohow! Ef I done wanted yo' t' git a move on, yo'd lay down
'side de road an' go to sleep. Whoa, now!"

But the noise of the shots had evidently frightened the long-eared
animal, and he was in no mood for stopping, now that he had once
started. It was not until some of the workmen ran out from the group
where they had gathered to watch Tom's test, and got in front of
Boomerang, that they succeeded in bringing him to a halt.

Eradicate climbed slowly down from the seat, and limped around until he
stood in front of his pet.

"Yo'--yo're a nice one, ain't yo'?" he demanded in sarcastic tones.
"Yo' done enough runnin' in a few minutes fo' a week ob Sundays, an'
now I won't be able t' git a move out ob ye! I'se ashamed ob yo', dat's
what I is! Puffickly ashamed ob yo'. Go 'long, now, an' yo' won't git
no oats dish yeah day! No sah!" and, highly indignant, Eradicate led
the now slowly-ambling mule off to the stable.

"I won't shoot again until you have him shut up, Rad!" laughed Tom. "I
didn't know you were so close when I set off those guns."

"Dat's all right, Mass a Tom," was the reply. "I done called t' you t'
wait, but yo' didn't heah me, I 'spects. But it doan't mattah, now.
Shoot all yo' laik, Boomerang won't run any mo' dis week. He done
runned his laigs off now. Shoot away!"

But Tom was not quite ready to do this. He wanted to see what effect
the first shots had had on his aerial warship, and to learn whether or
not the newly devised recoil check had done what was expected of it.

"No more shooting right away," called the young inventor. "I