Heins suggested that bank money was like a ball sent up by a solitary player, which might return or be lost according to the skill or awkwardness with which it was thrown; whereas exchange money was a shuttlecock played between two nations, which was sure to visit each in turn, as long as both were interested in keeping up the game. This flight of fancy, so much more French than Dutch, enhanced Francesca's admiration of the accomplishments of the young merchant. She was not aware, however, that bills of exchange could be exactly called money. She knew that they might, in one sense, be so considered, as they discharged debts; but debts might also be discharged by barter, where no money was present.--Heins explained that bills of exchange form an actual currency, temporary in its nature, like bank paper, but possessing all the requisites of a medium of exchange. "I have been using one as money this very day," he continued. "You must know,--(I do not hesitate to speak openly before friends)--I have been trying my fortune, while others did, in a venture to England. I am not in the habit of exporting, as you know; but I shipped a snug package of velvets, which certain great folks are at this moment wearing, perhaps in the king of England's own presence. I was paid in a bill drawn on a timber merchant here, payable at usance;----you know what that means?" Familiar as the term was, the young lady did not know what it meant. Heins explained that bills are paid either at sight, or at a certain specified time after date, or at the period which is pointed out by the custom or law of the place on which the bill is drawn; which period is called the usance of the place. At Amsterdam this was one month after date. Heins went on, "I was, at the same time, desirous of purchasing some powder and ball, which I had a fine opportunity of disposing of. I therefore offered this bill,--not to the owner of the powder, (who would leave Amsterdam before the bill became due, and would have charged me whatever it might cost him to have it changed for a different kind of money,)--but to my friend Visscher, the bill-broker, who sold me a bill on Copenhagen, which suited my powder-merchant's convenience, and put a profit into Visscher's pocket, and saved me the necessity of calling any money out of the Bank. So you see this bill was real money in my hands, is so now in Visscher's, and may be again in a hundred other hands before the month is up."