The river Seine runs through Paris, and winds and doubles so much that there are seven miles of it within the city walls. It is crossed by twenty-seven bridges, and from one of these, the Pont de la Concorde, we shall start on our tour through Paris. The upper part of this bridge is built of stones taken from the Bastille prison after its destruction by the enraged people. Thus the Parisians can feel, when they cross this bridge, that they are treading under foot a portion of the building they so greatly abhorred. The view up and down the river is very fine, and gives us a good idea of the city we are about to explore. As we cross to the northern side of the Seine, on which lies the most important part of Paris, we have directly in front of us, the great Place de la Concorde, a fine open square, in the center of which rises an obelisk brought from Egypt. Here are magnificent fountains, handsome statuary on tall pedestals, and crowds of vehicles and foot-passengers crossing it in every direction, making a picturesque and lively scene. This was not always as pleasant a place as it is now, for during the great French Revolution the guillotine stood in this square, and here were executed two thousand eight hundred persons, among whom were Queen Marie Antoinette and her husband, Louis XVI. To the east of this square extends for a long distance the beautiful garden of the Tuileries, which belonged to the royal palace of that name, before it was destroyed. This garden is shaded by long lines of trees, and adorned with fountains and statues. On its southern side is an elevated walk, or terrace, very broad and handsome, and about half a mile long. In the reign of the Emperor Napoleon the Third, this walk was appropriated to the daily exercise of the Prince Imperial. Here the young fellow could walk up and down without being interfered with by the people below; and underneath was a covered passage in which he could take long walks in rainy weather. [Illustration: ONE OF THE BRIDGES ACROSS THE SEINE,--SHOWING THE PLACE DE LA CONCORDE AND THE TUILERIES IN THE DISTANCE.]