handkerchief, closed his
note-book, and turned to Dexter.

"Now then," he said. "Let us see."

He took the sheet of paper, looked at one side, turned it over and
looked at the other, and then raised his eyes to Dexter's, which avoided
his gaze directly.

"What is this?" he cried.

"The equations, sir," said Dexter humbly.

"Tut--tut--tut!" ejaculated Mr Limpney. "Was there ever such a boy?
_plus_ where it ought to be _minus_, and--why, what's this!"

"This, sir?" said Dexter. "Half-crowns."

"But it was to be oranges. How many did he buy? and here you say he
bought ninety-seven half-crowns. I don't know how you arrived at it, or
what you mean. A man does not go to a shop to buy half-crowns. He
spent half a crown in oranges."

"Yes, sir."

"I believe it's sheer obstinacy. You do not want to do these
equations--simple equations too, mind you! Now then, about the
stage-coaches. When did they meet, and in what time from starting? Now
then--there are your figures, where did they meet? Look and tell me."

Dexter took the half-sheet of paper, stared at it very doubtfully, and
then looked up.

"Well!" said Mr Limpney. "Where did they meet?"

"Peterborough, sir."

"Where!" cried Mr Limpney in astonishment.

"Peterborough, sir."

"Now, will you have the goodness to tell me how you found out that?"

"On the map, sir."

"Bless my soul!" exclaimed the tutor. "Well, go on. At what time from
starting!"

"About ten o'clock, sir."

"Better and better," said the tutor sarcastically. "Now, will you
kindly explain--no, no, don't look at your figures--Will you kindly
explain how you arrived at this sapient conclusion?"

Dexter hesitated, and shifted one foot over the other.

"Well, sir, I am waiting," cried Mr Limpney, in a tone of voice which
made Dexter think very much resembled that of Mr Sibery when he was
angry.

"I--I--"

"Don't hesitate, sir. Have I not told you again and again that a
gentleman never hesitates, but speaks out at once? Now then, I ask you
how you arrived at this wonderful conclusion?"

"I tried over and over again, sir, with the _a's_ and _b's_, and then I
thought I must guess it."

"And did you guess it?"

"No, sir, I suddenly recollected what you said."

"And pray, what did I say!"

"Why, sir, you always said let _x_ represent the unknown quantity, and--
and _x_ stands for ten--ten o'clock."

Mr Limpney snatched the paper from the boy's hand, and was about