Paris extended in time even to these outer boulevards. Then, under Louis-Philippe, at the instigation of his Minister, M. Thiers, a line of fortifications was constructed around Paris; which, proving insufficient in 1870 and 1871 to save the capital from bombardment, has in its turn been surrounded by a circle of outlying detached forts intercommunicating with one another. The fortifications of Paris have had a strange history. At the time of their being planned, opinions in France were divided as to whether they were intended to oppose a foreign invasion or to control an internal revolt. In all probability they were meant, according to the occasion, to serve either purpose. They were not only designed by M. Thiers, but executed under his orders; and this statesman, who had made a careful study of military science, lived to see them powerless against the German army of investment, and successful against the Paris Commune. [Illustration: ON THE BOULEVARDS--CORNER OF PLACE DE L'OPÉRA.] Paris had been invaded and occupied in 1814, and again in 1815. On the other hand, domestic government had been upset in 1830 by a popular insurrection, which, with adequate military force to oppose it, might at once have been suppressed. Was it as patriot, people asked, or as minister of a would-be despotic king, that M. Thiers proposed to raise around Paris a new and formidable wall? M. Thiers's circular line of outworks played no part in connection with the successful insurrection of February, 1848, nor with the unsuccessful one of June in the same year. Nor was a single shot fired from the fortifications in connection with the _coup d'État_ of 1851. They did not in 1871 prevent the French capital from falling into the hands of the Germans: but they delayed for a considerable time the fatal moment of surrender; and if the army of Metz could have held out a few weeks longer--if, above all, the inhabitants of the inactive south, who practically took no part in the war, had been prepared, to fight with something like the energy displayed by the Confederates against the Federals during the American Civil War--then the fortifications would have justified the views of those who had chiefly regarded them as a valuable defence against foreign invasion. The fortifications erected by M. Thiers have since been pulled down: partly because the constantly expanding city wanted fresh building ground, partly because, in view of new plans of defence, and of the new artillery of offence, it was considered desirable to protect Paris by a system of outlying but inter-protecting forts, at a sufficient distance from the houses of the capital to render reduction by what is called "simple bombardment" impossible. In time Lutetia, with fresh developments, may require yet another new girdle. CHAPTER III. THE LEFT BANK AND THE RIGHT.