Mr. Twist had, it appeared, presented the steward and stewardess each with a dollar on behalf of the Misses Twinkler, but because the exchange was so favourable this had made no difference to the £5 notes. Reducing each £5 note into German marks, which was the way the Twinklers, in spite of a year in England, still dealt in their heads with money before they could get a clear idea of it, there would have been two hundred marks; and as it took, roughly, four marks to make a dollar, the two hundred marks would have to be divided by four; which, leaving aside that extra complication of variations in the exchange, and regarding the exchange for a moment and for purposes of simplification as keeping quiet for a bit and resting, should produce, also roughly, said Anna-Rose a little out of breath as she got to the end of her calculation, fifty dollars. "Correct," said Mr. Twist, who had listened with respectful attention. "Here they are." "I said roughly," said Anna-Rose. "It can't be _exactly_ fifty dollars. The tips anyhow would alter that." "Yes, but you forget the exchange." Anna-Rose was silent. She didn't want to go into that before Anna-Felicitas. Of the two, she was supposed to be the least bad at sums. Their mother had put it that way, refusing to say, as Anna-Rose industriously tried to trap her into saying, that she was the better of the two. But even so, the difference entitled her to authority on the subject with Anna-Felicitas, and by dint of doing all her calculations roughly, as she was careful to describe her method, she allowed room for withdrawal and escape where otherwise the inflexibility of figures might have caught her tight and held her down while Anna-Felicitas looked on and was unable to respect her. Evidently the exchange was something beneficent. She decided to rejoice in it in silence, accept whatever it did, and refrain from asking questions. "So I did. Of course. The exchange," she said, after a little. She gathered up the dollar bills and began packing them into her bag. They wouldn't all go in, and she had to put the rest into her pocket, for which also there were too many; but she refused Anna-Felicitas's offer to put some of them in hers on the ground that sooner or later she would be sure to forget they weren't her handkerchief and would blow her nose with them. "Thank you very much for being so kind," she said to Mr. Twist, as she stuffed her pocket full and tried by vigorous patting to get it to look inconspicuous. "We're never going to forget you, Anna-F. and me. We'll write to you often, and we'll come and see you as often as you like." "Yes," said Anna-Felicitas dreamily, as she watched the shore of Long Island sliding past. "Of course you've got your relations, but relations soon pall, and you may be quite glad after a while of a little fresh blood."