He had another young friend to whom he wrote pretty letters, Miss Mary Stevenson, daughter of the Mrs. Stevenson in whose house he lived in London when on his diplomatic missions to England. He encouraged her in scientific study, and some of his most famous explanations of the operations of nature are to be found in letters written to her. He had hoped that she would marry his son William, but William’s fancy strayed elsewhere. “PORTSMOUTH, 11 August, 1762. “MY DEAR POLLY “This is the best paper I can get at this wretched inn, but it will convey what is intrusted to it as faithfully as the finest. It will tell my Polly how much her friend is afflicted that he must perhaps never again see one for whom he has so sincere an affection, joined to so perfect an esteem; who he once flattered himself might become his own, in the tender relation of a child, but can now entertain such pleasing hopes no more. Will it tell _how much_ he is afflicted? No, it cannot. “Adieu, my dearest child. I will call you so. Why should I not call you so, since I love you with all the tenderness of a father? Adieu. May the God of all goodness shower down his choicest blessings upon you, and make you infinitely happier than that event would have made you....” (Bigelow’s Works of Franklin, vol. iii. p. 209.) This correspondence with Miss Stevenson continued for a great many years, and there are beautiful letters to her scattered all through his published works. The letters both to her and to Miss Ray became more serious as the two young women grew older and married. Miss Stevenson sought his advice on the question of her marriage, and his reply was as wise and affectionate as anything he ever wrote. She married Dr. Hewson, of London, and they migrated to Philadelphia, where she became the mother of a numerous family. Franklin had a younger sister, Jane, a pretty girl, afterwards Mrs. Mecom, of whom he was very fond, and he kept up a correspondence with her all his life, sending presents to her at Boston, helping her son to earn a livelihood, and giving her assistance in her old age. Their letters to each other were most homely and loving, and she took the greatest pride in his increasing fame. His correspondence with his parents was also pleasant and familiar. In one of his letters to his mother he amuses her by accounts of her grandchildren, and at the same time pays a compliment to his sister Jane.