The contents of the Green Vaults have for generations been a source of anxiety to the Saxon princes. Again and again, during the troublous times in Germany, they have been compelled to carry their treasures to the mountains in the region along the Elbe, known as the Saxon Switzerland, and to keep them there for security until the peril of plunder had passed. This sudden transportation of the royal valuables was very frequent during the Seven Years’ War, and it is reported that many of them were lost in the haste and excitement attending their removal. [Sidenote: THE GREEN VAULTS A TEMPTATION.] The Green Vaults offer a constant temptation to the rogues of the old world, and it would not be at all surprising if some man or men, possessed of a rare genius for pilfering, should yet accomplish what has so frequently failed. Robbery and burglary are so much a profession nowadays, and so much real talent is employed in their behalf, that those who have been graduated in the calling will be inconsiderate of their own interest if they do not some time perfect a scheme which will result in plundering the greatest and richest treasury on the globe. [Sidenote: CHANCE FOR A BURGLAR.] A rich reward awaits any one who will enter the Green Vaults of Dresden and carry away their treasures, or so much of them as could be easily carried by one man. Possibly an American or English burglar will yet be found who can succeed in this daring enterprise. XXI. THE CATACOMBS OF PARIS. THE FAIR CAPITAL UNDERMINED.—HISTORY OF THE VAST GRAVEYARD.—SIX MILLIONS OF SKELETONS.—A JOURNEY THROUGH THE CITY OF THE DEAD.—HORRIBLE SENSATIONS OF BEING LOST THERE.—GHASTLY DISPLAY OF SKULLS AND BONES.—TRAGIC AND COMIC INCIDENTS.—TERRIBLE EXPERIENCE IN THE MIGHTY CHARNEL-HOUSE.—SCENES NEVER TO BE FORGOTTEN. Few persons think, while strolling through the fashionable streets of Paris, and seeking pleasure in its charming precincts, that they are wandering over a vast graveyard, and that only a thin crust of earth separates them from the burial-place of six millions of human beings. Down there lie the remains of a third as many people as the entire French capital contains. A large part of the beautiful city is undermined by vaults, and these vaults, which are the famous Catacombs of Paris, contain the dead of centuries.