Note 1 — CHAPTER THE FIRST

The Pont d’Arc at Ardèche, over the river Ardèche, has a total height of sixty-six metres. From water-level to the crown of the arch is a flight of thirty-four metres; and in a span of fifty-nine metres this great natural bridge puts a huge vault over the river. As to the shape of the arch, it is pointed in a rather waved outline, and quite possibly it suggested the pointed arch to French bridge-builders long before the introduction of “ogivale” arches from the East (p. 88).