um-m_ of motors
could be heard in their workshop on the first floor of the headquarters
building at almost any hour.

Of course, the boys were not entirely sure that they would win first or
even third prize, because there were any number of others competing for
the same honors. Indeed, farmers and even business men in and around
Woodbridge were experimenting with chemical exterminators and various
other ingenious devices and all of these would have an equal chance with
the appliance invented by the boys. But the lads were sportsmen enough
to take their chances with the rest. Indeed, they even went so far as to
stake some of the precious motor money on the result, for they took
fifteen dollars from the Woodbridge bank to pay for the lumber and other
material needed to build Nipper's big vacuum pest catcher.

"If we don't win that prize now all our chances for a motorboat are gone
for sure," said Babe Wilson when Bud Weir announced the withdrawal of
part of the fund.

"Well, that isn't the way to look at it. Just say we are going to win
the prize and then get busy and work for it," insisted Bud, trying to
instil confidence in the stout scout.

Day by day the neatly finished boards grew to represent Nipper's idea of
a moth exterminator. And finally, after what seemed to the boys an
unusually long time, the suction fan arrived from Bruce's father's mill.
It was already attached to a one-quarter horsepower electric motor, for
Mr. Clifford knew that none of the motors in the scouts' workshop were
small enough to be used on a fan with six-inch blades. By this time the
lads had all but finished the big wooden trumpet and it was only
necessary to set the fan, bolt the motor into place and give the whole
thing a coat of paint.

But already the last Monday of the month had passed and only a day or two
remained in which the boys could test their machine before the judges.
Day and night since the beginning of the week contestants had been
claiming the attention of the judges with their schemes for
extermination. Most of these had been tried out and many were said to be
very successful. On one or two occasions the scouts had gone out to look
over these tests, but to their mind none of them looked as effective as
the moth trap they were building.

On Thursday night Mr. Ford visited headquarters looking rather anxious,
for he had heard very little from the boys during the last few days and
he was afraid they were not goi