HELLGATE AND SANDY HOOK.—ENTRANCES TO NEW YORK HARBOR.—THE HELLEGAT AND ITS MEANING.—STORIES OF THE OLD VOYAGERS.—EDITORIAL JOKES.—MAILLEFERT’S OPERATIONS.—DEEPENING THE CHANNEL.—GENERAL NEWTON.—THE AUTHOR ON AN EXCURSION.—BLOWING UP COENTIES’ REEF.—HOW IT IS DONE.—AN ACCIDENT WITH NITRO-GLYCERINE.—THE AUTHOR’S NARROW ESCAPE.—DIVER’S EXPERIENCE.—ASTONISHING THE FISHES.—RECEPTION AT HALLETT’S POINT.—GOING UNDER THE REEF.—THE MEN AT WORK.—AN INUNDATION.—HOW THE REEF IS TO BE REMOVED.—SURVEYING IN THE WATER.—A GRAND EXPLOSION. 882 LXIII. THE EARLY HISTORY OF MANKIND. THE STONE AGE.—PICTURE OF ADAM AND EVE.—HOW EVE CUT THE APPLE.—MINERS OF ANCIENT TIMES.—DISCOVERY OF STONE IMPLEMENTS.—THE INVENTION OF FIRE.—HOW GOLD WAS FOUND.—COPPER AND BRONZE.—THE BRONZE AGE.—IRON AND ITS USES.—MINERAL PRODUCTIONS OF DIFFERENT COUNTRIES.—QUICKSILVER IN SPAIN AND CALIFORNIA.—THE WEALTH OF NEVADA.—ROMANTIC STORY OF THE COMSTOCK LODE.—MINERAL FUTURE OF AMERICA. 898 LXIV. DIAMOND AND OTHER SWINDLES. THE GREAT DIAMOND SWINDLE OF 1872.—HOW IT WAS ORGANIZED.—MAGNIFICENT PLANS OF THE SWINDLERS.—PLANTING A DIAMOND FIELD.—HOW THE FRAUD WAS EXPOSED.—A NEAT SWINDLE ATTEMPTED IN SAPPHIRES.—HOW IT WAS DISCOVERED.—A MYTHICAL COPPER MINE.—FATE OF THE SWINDLER. 905 LXV. PERQUISITES. CURIOSITIES OF COMMERCIAL TRANSACTIONS.—PAYING COMMISSIONS IN EUROPE.—FUNNY EXPERIENCES.—SPREAD OF THE CUSTOM IN AMERICA.—HOW CONTRACTS ARE OBTAINED AND PAID FOR.—COMMISSIONS TO TRADESMEN AND OTHERS.—CURIOUS FEATURES OF THE PIANO TRADE. 917 LXVI. THE WIELICZKA SALT MINES. THE GREAT WIELICZKA SALT MINES, THE LARGEST IN THE WORLD.—THEIR HISTORY.—EXTENT AND PRODUCT.—DESCENT INTO AND EXPLORATION OF THEM.—WHAT IS TO BE SEEN.—MINERS AT WORK BLINDFOLDED.—WONDERFUL CHAMBERS.—GLOOM CONVERTED INTO SPLENDOR.—BANQUETS IN THE BOWELS OF THE EARTH.—THE INFERNAL LAKE.—HUMAN DEMONS.—AWFUL APPARITIONS.—EXTRAORDINARY NARRATIVES. 930 LXVII. EXPLOSIONS IN MINES. THICKNESS OF COAL SEAMS.—STUPIDITY OF A TURKISH MINING SUPERINTENDENT.—THE RESULT.—BLASTING IN MINES.—HOW IT IS DONE.—TERRIBLE ACCIDENTS.—MINES ON FIRE.—SCENES OF DEVASTATION.—EFFECT OF SUBTERRANEAN FIRE.—EXPLOSIONS OF FIRE-DAMP.—HORRIBLE ACCIDENTS.—STORIES OF SURVIVORS.—LOSS OF LIFE.—SCENE IN A WELSH MINE.—EXPLOSIONS IN ENGLISH AND AMERICAN MINES.—MODES OF RELIEF.—STORY OF TWO BROTHERS.—HOW THEY WERE SAVED.—THE SAFETY-LAMP.—ITS CONSTRUCTION.—THE FIRE-WALLS OF CHINA.—THE PENITENT AND CANNONEER. 948 LXVIII. MYSTERIES OF THE GRAND JURY.