Through this great London there rolls a great river, and there is scarcely any need to say what the name of that river is, for every child knows about the Thames. The great river cuts London into two parts, and on the south side of it there are many poor streets with poor people living in them, and close to the river is a palace, where the Archbishop of Canterbury lives. He is head of all the clergymen and all the bishops of the English Church. The palace has stood there for many hundreds of years, and it is curious to think that this important man, who has so much power, and who has the right to walk before all the dukes and earls when he goes to Parliament, lives there among the poor people on the south side of the river. The City, where men have their offices and go to work, is really quite a small part of London, but it is very important. Here there is the Bank of England, where bank-notes are made, and where there is gold in great bars lying in the cellars. The Bank has streets all round its four sides, as if it were an island, and the streets were rivers, and inside, in the middle of the building, there is a yard, with trees in it and a garden. It does seem so funny to find a garden here amongst all the houses. If you went into the Bank to see it, you would meet a man wearing a funny cocked hat like those that men used to wear in old times; and if you showed him that you had leave to go all over the building, he would tell you where to go and be very civil. We shall hear more about the Bank later on. Close to the Bank is the Mansion House, where the Lord Mayor lives. The Lord Mayor is a very grand person indeed. He is the head of the City, and a new Lord Mayor is chosen every year. There are other big buildings around near the Bank, and just here seven streets meet, and there is an open space. Now, if you were suddenly dropped down into that open space at, say, the middle of the day, you would most certainly be run over unless you stood close beside the very biggest policeman you could see, for every thing on wheels is coming in every direction--big motor-omnibuses, generally painted the most vivid scarlet, crammed with people inside and on the top; taxi-cabs with patient drivers, who would not jump if a gunpowder explosion went off under their noses; they have to keep good-tempered all day long, in spite of the tangle of traffic; immense lorries loaded with beer barrels; and little tiny carts with greengrocer's stuff, perhaps dragged by a dear little donkey, who looks as if he could run right under the bodies of the big dray-horses. And all these things are coming so fast and so close to one another, that it seems a miracle anyone can get through. Not long ago an underground passage with steps leading down to it was built, so that people can go under instead of over the street, which is, I think, a very good thing.