He felt no poignant regret when the month came to an end, and they returned to town to take possession of their Marylebone flat: for what was it but shifting the scene of their happiness? And after this had taken place, Peter was still too much occupied to have leisure for idle and mischievous thoughts. Marrying Sophia was, indeed, like loving Sir Richard Steele's fair lady, "a liberal education;" and Peter enjoyed the undivided benefit of her rare talent for instruction. He had been giving his attention to Astronomy of late, an unguarded remark of his having betrayed to Sophia the extreme crudity of his ideas respecting that science, and she had insisted upon his getting a popular primer, with diagrams, and mastering it as a preliminary to deeper study. One evening he was in the smaller room of the two that, divided by an arch, served for study and drawing-room combined; and he was busily engaged in working out a simple practical illustration, by the aid of one of the aforesaid diagrams. The experiment required a lamp, a ball of cotton, and an orange transfixed by a knitting-needle, and it had something to do with the succession of the seasons, solar and lunar eclipses, and the varying lengths of day and night on different portions of our globe, though he was not very clear what. "Don't you find you understand the inclination of the moon's orbit to the plane of the ecliptic better now?" said Sophia, as she came through the arch. "I think I shall, as soon as I can get the moon to keep steadier," he said, with more hope than he felt; "and it's rather hard to remember whereabouts I am supposed to be on this orange." "I must get you something to make that clearer," she said; "and you haven't tilted the orange nearly enough. But leave it for a moment; I've brought you in this packet of letters and things the people at your old rooms have just sent down. I wish, while I am away--I shall be back in a minute,--you would just run over them, and tell me if there are any papers you want kept, or if they may all be burnt." While she was gone, he undid the string which fastened the packet, and found, at the bottom of a mass of bills and documents of no value, the small oblong cheque-book which he had vowed never to see again. Somehow, as his eyes rested on its green cover, the old longing came upon him for a complete change of air and scene. He felt as if he _must_ get away from that orange: there were no lamps but electric lights, and no oranges, on board the _Boomerang_. But then, his last visit had not turned out a success: what if he were to find he had drawn another quarter of an hour with that irate matron of the music-room?