Leaving Arles for Marseilles we traverse a country as bare and uninteresting as an African desert. To the right, on the western side of the Rhone, lies the great plain of the Camargue, the delta of the river, composed of mingled salt mud and stagnant pools, the result of the contest between the waters of the Rhone and the sea; the former constantly pouring down immense volumes of _débris_, and the latter, obeying the impulse of the wind, as constantly driving it back upon the land. But the railway, keeping on the eastern side of the river, runs through a different but not less remarkable plain called the “Crau.” This consists of an immense accumulation of shingle, composed of water-worn and rounded stones of all sizes--the fabled scene of the fight of Hercules with the Ligurians, when Jupiter rained down these stones to provide the hero with ammunition. This extensive plain was a barren wilderness until a system of irrigation was introduced by the construction of the Canal de Craponne, whereby the water of the Durance is brought down for its fertilisation. Having at last crossed the Crau we arrive at ST CHAMAS, where the eye is relieved by the bright and peaceful prospect over the Etang de Berre, an extensive branch of the Mediterranean almost entirely surrounded with land. St Chamas is a quaint old town, with some of its houses hollowed out of the rock and traces of ancient ramparts. About half-a-mile distant may be seen an interesting Roman Bridge called the Pont Flavia. It is constructed with the usual solid masonry, and spans the river Touloubre with one arch, which is abutted by the rocky banks. The entrance at either end to the roadway over the bridge is through an arch, decorated with Corinthian columns and entablature. These archways are well preserved and are illustrated in Fergusson’s “Handbook of Architecture.” The columns are surmounted with lions, and the frieze bears an inscription shewing that the structure was erected by one of the Flavii. Some distance north from this, on the slope of the chain of the Vernégues, which divides the valley of the Durance from that of the Rhone, are to be found the relics of a small Corinthian temple, originally preceded with a peristyle of four columns in front, and pilasters of return on each side, of which, however, only one single pillar now survives. This was doubtless the site of the ancient Ernaginum.