This momentous pocketbook was a timely reminder to him of another transaction. On our return to the room upstairs (where he accounted for his absence by saying that it had been occasioned by circumstances over which he had no control), he took out of it a large sheet of paper, folded small, and quite covered with long sums, carefully worked. From the glimpse I had of them, I should say that I never saw such sums out of a school ciphering-book. These, it seemed, were calculations of compound interest on what he called “the principal amount of forty-one, ten, eleven and a half,” for various periods. After a careful consideration of these, and an elaborate estimate of his resources, he had come to the conclusion to select that sum which represented the amount with compound interest to two years, fifteen calendar months, and fourteen days, from that date. For this he had drawn a note-of-hand with great neatness, which he handed over to Traddles on the spot, a discharge of his debt in full (as between man and man), with many acknowledgements.