hat occupied his
thoughts.

"Nicholas," said the father.

"Just one minute, please," replied the lad, glancing hastily up: "I am
on the last of the problems that Mr. Layton gave us for this week, and
I have it almost finished."

The protest of the boy was so respectful that the father resumed his
smoking and waited until Nick laid his slate on the table and wheeled
his chair around.

"There, father, I am through."

"Read owed loud dot sum von you shoost don't do."

"Mr. Layton gave a dozen original problems as he called them, to our
class to-day, and we have a week in which to solve them. I like that
kind of work, and so I kept at it this evening until I finished them
all."

"You vos sure dot you ain't right, Nicholas, eh?"

"I have proved every one of them. Oh, you asked me to read the last one!
When Mr. Layton read that we all laughed because it was so simple, but
when you come to study it it isn't so simple as you would think. It is
this: If New York has fifty per cent. more population than Philadelphia,
what per cent. has Philadelphia less than New York?"

Mr. Ribsam's shoulders went up and down, and he shook like a bowl of
jelly. He seemed to be overcome by the simplicity of the problem over
which his son had been racking his brains.

"Dot makes me laughs. Yaw, yaw, yaw!"

"If you will sit down and figure on it you won't laugh quite so hard,"
said Nick, amused by the jollity of his father, which brought a smile to
his mother; "what is your answer?"

"If I hafs feefty tollar more don you hafs, how mooch less tollar don't
you hafs don I hafs? Yaw, yaw, yaw!"

"_That_ is plain enough," said Nick sturdily "but if you mean to say
that the answer to the problem I gave you is fifty per cent., you are
wrong."

"Oxplains how dot ain't," said Mr. Ribsam, suddenly becoming serious.

The mother was also interested, and looked smilingly toward her bright
son. Like every mother, her sympathies went out to him. When Nick told
his father that he was in error, the mother felt a thrill of delight;
she wanted Nick to get the better of her husband, much as she loved
both, and you and I can't blame her.

Nick leaned back in his chair, shoved his hands into his pockets, and
looked smilingly at his father and his pipe as he said:

"Suppose, to illustrate, that Philadelphia has just one hundred people.
Then, if New York has fifty per cent. more, it must have one hundred and
fifty people as its population; that is co