Hardly had he crossed when a frightful misfortune occurred. The bridge had been mined, to blow it up on the approach of the foe. This duty had been carelessly trusted to a subaltern, who, frightened by seeing some of the enemy on the river-side, set fire hastily to the train. The bridge blew up with a tremendous explosion, leaving a rear-guard of twenty-five thousand men in Leipsic cut off from all hope of escape. Some officers plunged on horseback into the stream and swam across. Prince Poniatowsky, the gallant Pole, essayed the same, but perished in the attempt. The soldiers of the rear-guard were forced to surrender as prisoners of war. In this great conflict, which had continued for four days, and in which the most of the nations of Europe took part, eighty thousand men are said to have been slain. The French lost very heavily in prisoners and guns. Only a hasty retreat to the Rhine saved the remainder of their army from being cut off and captured. On the 20th Napoleon succeeded in crossing that frontier river of his kingdom with seventy thousand men, the remnant of the grand army with which he had sought to hold Prussia after the disastrous end of the invasion of Russia. [Illustration: A GERMAN MILK WAGON.] Germany was at length freed from its mighty foe. The garrisons which had been left in its cities were forced to surrender as prisoners of war. France in its turn was invaded, Paris taken, and Napoleon forced to resign the imperial crown, and to retire from his empire to the little island of Elba, near the Italian coast. In 1815 he returned, again set Europe in flame with war, and fell once more at Waterloo, to end his career in the far-off island of St. Helena. Thus ended the empire founded by the great conqueror. The next to claim the imperial title was Louis Napoleon, who in 1851 had himself crowned as Napoleon III. But his so-called empire was confined to France, and fell in 1870 on the field of Sedan, himself and his army being taken prisoners. A republic was declared in France, and the second French empire was at an end. And now the empire of Germany was restored, after having ceased to exist for sixty-five years. The remarkable success of William of Prussia gave rise to a wide-spread feeling in the German states that he should assume the imperial crown, and the old empire be brought again into existence under new conditions; no longer hampered by the tradition of a Roman empire, but as the title of united Germany.