On the farther side of this gate stretches one of the most noted streets in Europe. For if Berlin is the heart of Germany, so is the street called "Unter den Linden" (Under the Lime-Trees) the centre and heart of Berlin. There are, indeed, streets which are longer, for this extends only two-thirds of a mile, but hardly any which are broader, for it is 66 yards across. Between its alternate carriage-roads and foot-walks four double rows of limes and chestnuts introduce a refreshing breath of open country right into the bosom of the great town of stone, with its straight streets and heavy, grey square houses. As we wander along "Unter den Linden" we pass the foreign embassies and the German government offices, and, farther on, the palace of the old Kaiser Wilhelm, which is unoccupied and has been left exactly as it was in his lifetime. He used to stand at a corner window on the ground floor, and look out at his faithful people. It is now just noon. Splendid carriages and motor cars sweep past, and the crush of people on the pavements is great. We hear the inspiriting music of a military band, and the Imperial Guard marches down the street, followed by crowds of eager sightseers. Keeping time with the music we march with them past the great Royal Library to where Frederick the Great looks down from his tall bronze horse on the children of to-day. On the one side is the Opera House, on the other is the University, with its ten thousand students, and farther on the Arsenal, with its large historical collections of engines of war. We cross over the "Schlossbruecke" (Palace Bridge), which throws its arch over the River Spree, and follow the parade into the "Lustgarten" (Pleasure Garden). The band halts at the foot of the statue of Frederick William III. and the people crowd round to listen, for now one piece is played after another. Thus the good citizens of Berlin are entertained daily. There are several noteworthy buildings round the Lustgarten, among them many art museums and picture galleries, as well as the Cathedral and the Royal Palace (Plate I.). It looks very grand, this palace, though it does not stand, as it should, in the middle of a great open space, but is hemmed in by the streets around it. Perhaps it would interest you to hear about a ball at the Imperial Court of Germany. At the stroke of nine our carriage drives in under the archway of the Palace. The carpeted staircases are lined by "Beef-eaters," in old-fashioned uniforms, as motionless as if they were cast in wax. They do not turn even their eyes as the guests pass, much less their heads. Now we are up in the state rooms, and move slowly over the brightly polished floor through a suite of brilliant apartments glittering with electric light. Pictures of the kings of Prussia stand out against the gilt leather tapestry. At last we reach the great throne-room, which takes its name from the black eagles on the ceiling. [Illustration: PLATE I. BERLIN.