"Yes, it is; but I ought to add that it is not always so sure. All ventures do not turn out so profitably. To return to your affairs I shall charge you interest on the five hundred dollars you borrowed of me, at the rate of seven per cent. You have had the use of the money for three months."
"Then the interest will amount to eight dollars and three quarters," said Henry, promptly.
"Quite right; you are very quick at reckoning," said Mr. Hamilton, looking pleased.
"That is not a difficult sum," answered Henry, modestly.
"I did not suppose you knew much about computing interest. You left school very young, did you not?"
"At twelve, sir."
"You had not studied interest then, had you?"
"No, sir; I have studied it since."
"At evening-school?"
"No, sir; I studied by myself in the evening."