The oldest, that erected by the troops of Marcus Antoninus, drew its waters by two branches, from the group of hills, called in modern times, Mont d'Or : this stream having been found inadequate for the proper supply of even the highest division of the city, a second aqueduct was constructed, which drew its water from the Loire. The third aqueduct was formed under, to conduct water to the highest part of the city, on which was erected the palace built by the Emperor Claudius. Remains of other minor aqueducts, built in the same age, are of the same construction, the arches and parts apparent being of the masonry called A fourth aqueduct, formed along the bank by the ancients opus reticulatum. of the Rhone, appears to have been the source from which the lower city received its

supply of water ; and from its remains there is little question but that it . also was constructed by the Romans. The Claudian aqueduct, being that which has most attracted the attention of antiquaries, will be described more in detail.

The body of the work, that is, the arcades that carried the aqueduct across the valleys, is built of masses of rubble stone and cement, faced, as has been stated, with the

opus reticulatum. In this instance, this kind of work is supposed to have been formed by laying a bottom of brick, of two, three, or four layers, then a caisson of wooden sides was applied to it,- and fixed thereon. The caisson was first lined with the squared stones which were to form the face the middle was then filled with rubble stones, into which ;