The aqueduct has been constructed with the same care throughout its great length, the only difference being that, in the parts exposed, the aqueduct was covered with slabs, and in the subterranean portion it was covered with a semi-circular arch, of a species of rubble roughly squared in the joints, nearly two feet in thickness.

In examining the water channel, a strong concretion is observable, adhering to the cement on the sides and bottom. This petrifaction is nearly twenty-nine centimetres thick, or 11 and one-third inches, and from this it appears, that the general height of the stream of water in the channel was about three feet nine inches.

This interesting monument of ancient Roman magnificence was demolished at its two ends, some time about the beginning of the fifth century, by the barbarians who then besieged Nismes, and who, by this means, endeavored to force the citizens to surrender. beginning of the eighteenth century, when It remained in this state until the

the Duke de Rohan, in order to make a passage for his artillery, perforated the piers of and by some other operations directed to the same end, the Pont du the second arcade, Garde was rapidly falling to pieces. Considerable rents in the walls, and deviations from the perpendicular, exciting public attention, the provincial States took the matter into consideration, and by a series of judicious repairs, they succeeded in restoring this ornament of Languedoc to the state in which it was, before the dilapidations of the Due de Rohan.