Section I. PRELIMINARY CONSIDERATIONS, from p. 109 to p. 112. Section II. AMONG THE HERALDS OF MAN, from p. 113 to p. 124. Section III. THE SLAB-BRIDGE WITH STONE PIERS, from p. 125 to p. 128. Section IV. TREE-BRIDGES WITH STONE PIERS, from p. 129 to p. 132. Section V. TREE-BRIDGES WITH TIMBER PILES, from p. 133 to p. 135. Section VI. SOME TYPICAL TIMBER BRIDGES, from p. 136 to p. 143. Section VII. PRIMITIVE SUSPENSION BRIDGES, from p. 144 to p. 149. Section VIII. NATURAL ARCHES--THEIR SIGNIFICANCE AND THEIR INFLUENCE, from p. 150 to p. 164. CHAPTER THE THIRD A FEW WORDS ON THE ROMAN GENIUS 165 CHAPTER THE FOURTH OLD BRIDGES, EUROPEAN, PERSIAN AND CHINESE 205 CHAPTER THE FIFTH ON THE EVOLUTION OF UNFORTIFIED BRIDGES 329 APPENDIX I CHINESE GABLED BRIDGES 365 APPENDIX II STEEP ROMAN BRIDGES 367 INDEX AND GLOSSARY 369 LIST OF COLOUR PLATES _Frontispiece._ PONT ST. BÉNÉZET OVER THE RHÔNE AT AVIGNON. Built between the years 1177 and 1185. _National Gallery of Australia._ TO FACE PAGE RAILWAY BRIDGE AT ALBI IN FRANCE 8 PONT VALENTRÉ AT CAHORS IN FRANCE: THE FORTIFIED GATES AND TOWERS. Thirteenth Century. See also the second picture of this Bastille Bridge 16 THE ALCÁNTARA AT TOLEDO. Mainly the work of Archbishop Tenorio, A.D. 1380; fortified by Andres Manrique, A.D. 1484. _Collection of Miss E. C. Rossignol_ 32 WAR-BRIDGE OF THE MIDDLE AGES AT PARTHENAY IN FRANCE 36 CANNON STREET RAILWAY BRIDGE, LONDON. _Collection of the Fine Art Society_ 48 OLD LONDON BRIDGE. Begun by Peter Colechurch in 1176, and finished by a Frenchman, called Isembert, in the year 1209 52 OLD BRIDGE OVER THE CLAIN NEAR POITIERS 56 AT ALBI ON THE TARN IN FRANCE. Showing on our right the Old Houses, and beyond the Bridge, on our left, the great Old Church, famous for its fortifications 72 TOWER BRIDGE, LONDON. _Collection of John Lane, Esq._ 80 FAMOUS BRIDGE AT ESPALION IN FRANCE. Said to date from the Eighth Century 88 PONT DU TARN AT ALBI IN FRANCE. Said to date from about the years 1035-40 92