“Do you tell that stupid Jack, that if he doesn’t want to offend me so that I’ll never, never forgive him, he is to bring his slate and pencil over here after supper this evening. And you’ll come, too, with your geography. Yours truly, Susan Lanham, Professor of Mathematics and Natural Science in the Greenbank Independent and Miscellaneous Academy. Do you hear?”

“All right.” And Columbus, smiling faintly, went off to tell Jack the good news. That evening Susan had, besides her own brother and two sisters, two pupils who learned more arithmetic than they would have gotten in the same time from Mr. Ball, though she did keep them laughing at her drollery. The next evening, little Joanna Merwin joined the party, and Professor Susan felt quite proud of her “academy,” as she called it.

Bob Holliday caught the infection, and went to studying at home. As he was not so far advanced as Jack, he contented himself with asking Jack’s help when he was in trouble. At length, he had a difficulty that Jack could not solve.

“Why don’t you take that to the professor?” asked Jack. “I’ll ask her to show you.”

“I dursn’t,” said Bob, with a frightened look.

“Nonsense!” said Jack.

That evening, when the lessons were ended, Jack said:

“Professor Susan, there was a story in the old First Reader we had in the first school that I went to, about a dog who had a lame foot. A doctor cured his foot, and some time after, the patient brought another lame dog to the doctor, and showed by signs that he wanted this other dog cured, too.”

“That’s rather a good dog-story,” said Susan. “But what made you think of it?”

“Because I’m that first dog.”