"Oh, I get you," said Estelle. "You mean--"
"Rocks," cried Marie, getting the word in ahead of Estelle.
"That's it," Katherine admitted. "We'll shower rocks at anybody that makes us any more trouble."
"Very ingenious," Miss Ladd said approvingly. "If those persons who visited us last night come again, they'll get a warm reception."
"And a hard one," Marion supplemented.
"I have another idea," Helen announced, and everybody turned attention to her. "I have some heavy rubber bands in my grip. I always carry them because they come in very handy sometimes."
"What can you do with them?" Estelle asked.
"What do you think?" Helen returned.
"I know," cried Ethel Zimmerman. "Make catapults with them."
"Good!" several of the girls exclaimed.