Certainly, as the days passed, it could not be said that Billy was not tending to her husband and her home. From morning till night, now, she tended to nothing else. She seldom touched her piano--save to dust it--and she never touched her half-finished song-manuscript, long since banished to the oblivion of the music cabinet. She made no calls except occasional flying visits to the Annex, or to the pretty new home where Marie and Cyril were now delightfully settled. The opera and the Symphony were over for the season, but even had they not been, Billy could not have attended them. She had no time. Surely she was not doing any “gallivanting” now, she told herself sometimes, a little aggrievedly. There was, indeed, no time. From morning until night Billy was busy, flying from one task to another. Her ambition to have everything just right was equalled only by her dogged determination to “just show them” that she could do this thing. At first, of course, hampered as she was by ignorance and inexperience, each task consumed about twice as much time as was necessary. Yet afterwards, when accustomedness had brought its reward of speed, there was still for Billy no time; for increased knowledge had only opened the way to other paths, untrodden and alluring. Study of cookbooks had led to the study of food values. Billy discovered suddenly that potatoes, beef, onions, oranges, and puddings were something besides vegetables, meat, fruit, and dessert. They possessed attributes known as proteids, fats, and carbohydrates. Faint memories of long forgotten school days hinted that these terms had been heard before; but never, Billy was sure, had she fully realized what they meant. It was at this juncture that Billy ran across a book entitled “Correct Eating for Efficiency.” She bought it at once, and carried it home in triumph. It proved to be a marvelous book. Billy had not read two chapters before she began to wonder how the family had managed to live thus far with any sort of success, in the face of their dense ignorance and her own criminal carelessness concerning their daily bill of fare. At dinner that night Billy told Bertram and William of her discovery, and, with growing excitement, dilated on the wonderful good that it was to bring to them. “Why, you don't know, you can't imagine what a treasure it is!” she exclaimed. “It gives a complete table for the exact balancing of food.” “For what?” demanded Bertram, glancing up. “The exact balancing of food; and this book says that's the biggest problem that modern scientists have to solve.” “Humph!” shrugged Bertram. “Well, you just balance my food to my hunger, and I'll agree not to complain.”