There is a great part of London where people only go to work, and from which they come away again at nights. In the mornings hundreds and hundreds of men pour into this part as fast as the trains can bring them, and go to their offices, which are in great buildings, many different offices being in one building; and the streets are filled with men hurrying this way and that, always in a hurry. There is no one standing about or idling. Omnibuses and carts and cabs are all mixed up together in the roadway, until you would think it was impossible for them ever to be disentangled again. And now and then some bold man on a bicycle dares to ride right into the middle of it all, between the wheels and under the horses' noses, and how he ever gets through without being crushed up as flat as a paper-knife is a wonder! At nights, when the men have done their day's work, they are in as much of a hurry to get out of this part of London, which is called the City, as they were to get into it in the morning. They go by cabs and omnibuses and trains back to their homes and their children, and the City is left still and silent, with just a quiet cat flitting across the street, and making a frightened jump when the big policeman turns his lantern on to her. The children of rich people seldom see this part of London. Perhaps their father goes there every day, and they hear him talk of the City, but it is like another town to them, so vague and far away it seems. These children probably have lessons with their governess at home, and when twelve o'clock comes they go for a walk. When they open the front-door they see a long street, stretching both ways, filled with dark, dull-looking houses just the same as their own. The street pavement is made of wood, which is quieter than stones, and when the cabs run past they make very little sound. If the children are lucky they live in a square, and there is a garden in the middle, with iron railings round it, and everyone who lives in the square has a key to open the gate; but it must not be left open, or other people would get in and use the garden too. It has green grass in it and flower-beds, and it is all very prim and proper, and not at all interesting; and, worst of all, the dear dogs, Scamp and Jim, cannot go there, even when they are led by a string. The gardener would turn them out, for he imagines they would kick about in his flower-beds and rake out the seeds. This is not the sort of garden that a country child would care for. But Jack and Ethel are not country children; they are quite used to their garden, and like it very much.