[Illustration: LAROQUE ON THE RIVER LOT, NEAR CAHORS, A SORT OF INLAND GIBRALTAR; A PART OF THE VILLAGE IS BUILT ON BRIDGES THROWN ACROSS CHASMS IN THE ROCKS] Before we pass on from the defensive bridges, I should like to give you a picture of the famous old bridge at Saintes, in France, that lasted to the year 1843, when it was destroyed. I know not why I use the silly word “it,” for the bridge of Saintes was an exceedingly martial structure that united all the main phases of military art--the primitive, the Roman, and the mediæval. Let me give an abridged description from Viollet-le-Duc’s “Dictionnaire raisonnée d’Architecture”:-- “The first gate appeared on the right shore of the Charente, on the side of the Faubourg des Dames; next came the Roman arch,[127] the upper part of which was crenellated during the Middle Ages; next on the side of the town stood a tower of oval plan, through which the road lay; the town gates with flanking towers closed the end of the bridge. From the first gate to the Roman arch the bridge was of wood, as was also the case between the great tower and the town gates, so that by the removal of this part of the roadway all communication could be cut off between the town and the tower, as well as between the bridge and the Faubourg; moreover, the parapets were crenellated, so that the garrison of the town at any moment could stop all navigation.” V A brief introduction to the history of bridges has so many difficulties that I creep through my work, a few hundred words in a long day. To try to plant an oak tree in a thimble would be more difficult, I suppose, but gleaning here and there over vast fields brings trouble enough to any writer. I go through scores of photographs, and turn over great piles of notes, and seek for a topic that is not too technical for the general reader, but that touches a really important phase in the evolution of bridge-building. There is a species of bridge to which the arches at Laroque belong; it may be called either freakish or very exceptional. Let me give a few examples.