The streets of London are in some places very narrow--too narrow to allow tram-cars to run through them as they do in some other large towns, and at the height of the season the blocks in the traffic in some of the West-End streets are quite alarming. Imagine a tightly-packed mass of vehicles, restive horses in splendid carriages, huge motor-omnibuses, smart automobiles, taxi-cabs, and tradesmen's vans, all squeezed together. Perhaps the policeman has held up his hand at a crossing to let some carriages get across from a side street, and everything has had to stop, public and private alike. Stand up on the top of an omnibus and look this way and that: what can you see? Rows and rows of great omnibuses crowded with people, both outside on the roof and inside, all waiting just because one man has held up his hand. Nothing astonishes foreigners more than this; indeed, some people say it is the one thing Frenchmen like most to see in London--the power of the policeman. He has perfect control of all the traffic, and if he says a thing must stop, it must obey him even if it be the carriage of a duke. In Paris they tried to imitate this, and they gave their policemen little white wands to hold up to stop the traffic when it was necessary; but the drivers of the cabs took no notice, and the poor French policeman would run about yelling at them and waving his little white wand and shouting to them to stop, and when they took no notice he grew more and more angry until he was almost frantic--so different from our calm, grave policeman with his majestic arm. Sometimes, when the roadway is thick with carts and cabs and carriages, there is a roar in the distance, a shout of many voices that makes your heart stand still. It comes again, louder and louder, nearer and nearer, and all the vehicles pull to one side and make a lane down the middle of the road. Right up this lane dashes a shining fire-engine, with the smoke and sparks flying out behind, the men in the glistening helmets clinging on to the sides, and the driver guiding it so skilfully as it spins over the ground far quicker than it takes to tell. In a minute they have dashed out of sight; then the traffic closes up again. But there is another shout, another roar, and another engine follows the first; the firemen clinging to it are shouting all together a noise that sounds like 'Ah-h-h! ah-h-h!' to warn other things to get out of their way. Soon a third comes, and then follows a great red ladder on wheels, pushed by men on foot--that is a fire-escape. The fire can't be far away, so we run after the excited crowd, and soon come to a street blocked with people, where flames and smoke are shooting out of the windows. It is a house where many girls are employed in a dressmaking business, and some of them have been got safely out; but there are others at those high windows, screaming for help and stretching out their arms. The brave firemen