The Age of Coal—Plants of the Carboniferous Age—Hugh Miller’s Description of a Coal Forest—Vast Time required for the Formation of the Coal-fields—Derangements and Dislocations—Faults—Their Disadvantages and Advantages— Bituminous Coals—Anthracites—Our Black Diamonds— Advantageous Position of our Coal-Mines—The South Welsh Coal-field—Great Central and Manchester Coal-fields—The Whitehaven Basin and the Dudley Area—Newcastle and Durham Coal-fields—Costly Winnings—A Ball in a Coal-pit— Submarine Coal Mines—Newcastle—View from Tynemouth Priory—Hewers—Cutting Machines—Putters—Onsetters— Shifters—Trapper-boys—George Stephenson—Rise of Coal Production—Probable Duration of our Supply—Prussian Coal Mines—Belgian Coal Mines—Coal Mines in various other countries—Maunch Chunck 390 CHAPTER XXXIII. BITUMINOUS SUBSTANCES. Formation of Petroleum—Enormous Production of the Pennsylvanian Wells—Asphalte used by the Ancients— Asphalte Pavements—The Pitch Lake of Trinidad—Jet—Its Manufacture in Whitby 426 CHAPTER XXXIV. SALT. Geological Position of Rock Salt—Mines of Northwich—Their immense Excavations—Droitwich and Stoke—Wieliczka— Berchtesgaden and Reichenhall—Admirable Machinery— Stassfurt—Processes employed in the Manufacture of Salt— Origin of Rock-salt Deposits 431 CHAPTER XXXV. SULPHUR. Sulphur Mines of Sicily—Conflagration of a Sulphur Mine— The Solfataras of Krisuvick—Iwogasima in Japan—Solfatara of Puzzuoli—Crater of Teneriffe—Alaghez—Büdöshegy in Transylvania—Sulphur from the Throat of Popocatepetl— Sulphurous Springs—Pyrites—Mines of San Domingo in Portugal—The Baron of Pommorão 441 CHAPTER XXXVI. AMBER. Various Modes of its Collection on the Prussian Coast—What is Amber?—The extinct Amber Tree—Insects of the Miocene Period inclosed in Amber—Formidable Spiders—Ancient and Modern Trade in Amber 449 CHAPTER XXXVII. MISCELLANEOUS MINERAL SUBSTANCES USED IN THE INDUSTRIAL ARTS. Alum—Alum Mines of Tolfa—Borax—The Suffioni in the Florentine Lagoons—China-clay—How formed?—Its Manufacture in Cornwall—Plumbago—Emery—Tripolite 458 CHAPTER XXXVIII. CELEBRATED QUARRIES.