unced Randy. He and his twin brother were always ready for a joke.

"What is it?" questioned Jack quickly.

"This snow is just soft enough for rolling some big balls, as we found
out this afternoon," answered his cousin. "What's the matter with making
a whole lot of big snowballs and placing 'em in some of the bedrooms
to-night?"

"Gee, that's the talk!" cried his twin merrily. "I'd like to place a
couple in Codfish's room."

"He certainly deserves 'em," added Fred. "He's getting to be just as big
a sneak as he ever was. All of our kindness to him seems to have been
useless."

"And I thought he was going to turn over a new leaf," declared Jack. "I
wonder if some of the other fellows haven't been teasing him and that has
made him go back to his old tricks."

"I know one person I'd like to treat to some big snowballs!" broke out
Fred. "That's Professor Duke."

"Oh, say! I'd like to square up with him myself," burst out Andy. "Gee!
he certainly did have it in for us yesterday."

"Professor Duke is certainly a sour one--much worse than Asa Lemm ever
dared to be," came from Gif.

"I was thinking of Duke when I mentioned it," said Randy. "You know he
has his room in our building instead of with the other professors in
Colonel Colby's residence."

"We don't want to get in bad with the colonel," remarked Fred seriously.

"Oh, I think we can fix it so that nobody will know who did it," returned
his cousin.

The matter was talked over for several minutes, and then, having agreed
on their plan for more fun, the Rover boys and their chums set to work
rolling a number of snowballs which were two feet or more in diameter.
These they placed close to the school building at a point where there was
a series of fire-escapes leading down from the upper halls of the
institution.

"We can let down the ladder just as soon as we're ready to turn the
trick," announced Randy. "I don't believe anybody will notice it, for it
will be dark and so cold that most everybody will be indoors."

"We've got to be on our guard to make certain that Codfish or Duke or
somebody else doesn't spot us," said Spouter Powell. "Of course it
wouldn't hurt if some of the regular fellows found us out, because they'd
keep it to themselves."

It must be confessed that the Rover boys were rather preoccupied in mind
during supper that evening. In fact, Andy grew so thoughtless that he
salted some eggs he was eating three times, so that when he finally ca