Origin of Sand--Sand now carried down to the Sea--The Sands of Egypt and the adjacent Desert--The Suez Canal--The Sands of Egypt--Coast Dunes and Sand Plains--Sand Banks--Dunes on Coast of America--Dunes of Western Europe--Formation of Dunes--Character of Dune Sand--Interior Structure of Dunes--Form of Dunes--Geological Importance of Dunes--Inland Dunes--Age, Character, and Permanence of Dunes--Use of Dunes as Barrier against the Sea--Encroachments of the Sea--The Luemfjord--Encroachments of the Sea--Drifting of Dune Sands--Dunes of Gascony--Dunes of Denmark--Dunes of Prussia--Artificial Formation of Dunes--Trees suitable for Dune Plantations--Extent of Dunes in Europe--Dune Vineyards of Cape Breton--Removal of Dunes--Inland Sand Plains--The Landes of Gascony--The Belgian Campine--Sands and Steppes of Eastern Europe--Advantages of Reclaiming Dunes--Government Works of Improvement, 451 CHAPTER VI. PROJECTED OR POSSIBLE GEOGRAPHICAL CHANGES BY MAN. Cutting of Marine Isthmuses--The Suez Canal--Canal across Isthmus of Darien--Canals to the Dead Sea--Maritime Canals in Greece-- Canal of Saros--Cape Cod Canal--Diversion of the Nile--Changes in the Caspian--Improvements in North American Hydrography-- Diversion of the Rhine--Draining of the Zuiderzee--Waters of the Karst--Subterranean Waters of Greece--Soil below Rock-- Covering Rocks with Earth--Wadies of Arabia Petraea--Incidental Effects of Human Action--Resistance to great Natural Forces-- Effects of Mining--Espy's Theories--River Sediment--Nothing small in Nature, 517 CHAPTER I. INTRODUCTORY. NATURAL ADVANTAGES OF THE TERRITORY OF THE ROMAN EMPIRE--PHYSICAL DECAY OF THAT TERRITORY AND OF OTHER PARTS OF THE OLD WORLD--CAUSES OF THE DECAY--NEW SCHOOL OF GEOGRAPHERS--REACTION OF MAN UPON NATURE-- OBSERVATION OF NATURE--COSMICAL AND GEOLOGICAL INFLUENCES--GEOGRAPHICAL INFLUENCE OF MAN--UNCERTAINTY OF OUR METEOROLOGICAL KNOWLEDGE-- MECHANICAL EFFECTS PRODUCED BY MAN ON THE SURFACE OF THE EARTH-- IMPORTANCE AND POSSIBILITY OF PHYSICAL RESTORATION--STABILITY OF NATURE--RESTORATION OF DISTURBED HARMONIES--DESTRUCTIVENESS OF MAN-- PHYSICAL IMPROVEMENT--HUMAN AND BRUTE ACTION COMPARED--FORMS AND FORMATIONS MOST LIABLE TO PHYSICAL DEGRADATION--PHYSICAL DECAY OF NEW COUNTRIES--CORRUPT INFLUENCE OF PRIVATE CORPORATIONS, _note_. _Natural Advantages of the Territory of the Roman Empire._