The elder Ribsam took several puffs from his pipe, his eyes fixed dreamily on the fire, as though in deep meditation. His wife sat in her chair on the other side, and was busy with her knitting, while perhaps her thoughts were wandering away to that loved Fatherland which she had left so many years before, never to see again. Nellie had grown sleepy and gone to bed.

Mr. Ribsam turned his head and looked at Nick. The boy was seated close to the lamp on the table, and the scratching of his pencil on his slate and his glances at the slip of paper lying on the stand, with the problems written upon it, told plainly enough what 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 correct, is it not, father?"

Mr. Ribsam took another puff or two, as if to make sure that his boy was not leading him into a trap, and then he solemnly nodded his head.

"Dot ish so,—dot am,—yaw."

"Then if Philadelphia has one hundred people for its population, New York has one hundred and fifty?"

"Yaw, and Pheelatelphy has feefty per cent. less—yaw, yaw, yaw!"

"Hold on, father,—not so fast. I'm teacher just now, and you mustn't run ahead of me. If you will notice in this problem the per cent. in the first part is based on Philadelphia's population, while in the second part it is based on the population of New York, and since the population of the two cities is different, the per cent. cannot be the same."

"How dot is?" asked Mr. Ribsam, showing eager interest in the reasoning of the boy.

"We have agreed, to begin with, that the population of Philadelphia is one hundred and of New York one hundred and fifty. Now, how many people will have to be subtracted from New York's population to make it the same as Philadelphia?"

"Feefty,—vot I says."

"And fifty is what part of one hundred and fifty,—that is, what part of the population of New York?"

"It vos one thirds."

"And one third of anything is thirty-three and one third per cent. of it, which is the correct answer to the problem."

Mr. Ribsam held his pipe suspended in one hand while he stared with open mouth into the smiling face of his son, as though he did not quite grasp his reasoning.

"Vot you don't laughs at?" he said, turning sharply toward his wife, who had resumed her knitting and was dropping many a stitch because of the mirth, which shook her as vigorously as it stirred her husband a few minutes before.

"I laughs ven some folks dinks dey ain't shmarter don dey vosn't all te vile, don't it?"

And stopping her knitting she threw back her head and laughed unrestrainedly. Her husband hastily shoved the stem of his pipe between his lips, sunk lower down in the chair, and smoked so hard that his head soon became almost invisible in the vapor.

By-and-by he roused himself and asked Nick to begin with the first problem and reason out the result he obtained with each one in turn.

Nick did so, and on the last but one his parent tripped him. A few pointed questions showed the boy that he was wrong. Then the hearty "Yaw, yaw, yaw!" of the father rang out, and looking at the solemn visage of his wife, he asked:

"Vy you don't laughs now, eh? Yaw, yaw, yaw!"

The wife meekly answered that she did not see anything to cause mirth, though Nick proved that he did.

Not only that, but the son became satisfied from the quickness with which his father detected his error, and the keen reasoning he gave, that he purposely went wrong on the first problem read to him with the object of testing the youngster.

Finally, he asked him whether such was not the case. Many persons in the place of Mr. Ribsam would have been tempted to fib, because almost every one will admit any charge sooner than that of ignorance; but the Dutchman considered lying one of the meanest vices of which a man can be guilty. Like all of his countrymen, he had received a good school education at home, besides which his mind possessed a natural mathematical bent. He said he caught the answer to the question the minute it was asked him, and, although Mr. Layton may not have seen it before, Mr. Ribsam had met and conquered similar ones when he was a boy.

While he persistently refused to show Nick how to solve some of the intricate problems brought home, yet when the son, after hours of labor, was still all abroad, his father would ask him a question or two so skillfully framed that the bright boy was quick to detect their bearing on the subject over which he was puzzling his brain. The parent's query was like the lantern's flash which shows the ladder for which a man is groping.

The task of the evening being finished, Mr. Ribsam tested his boy with a number of problems that were new to him. Most of them were in the nature of puzzles, with a "catch" hidden somewhere. Nick could not give the right answer in every instance, but he did so in a majority of cases; so often, indeed, that his father did a rare thing,—he complimented his skill and ability.