structures built by the Romans at Metz, belongs to a time more remote, and that the date of the reign of the first emperors may be the era when the legions of Caesar occupied the country of the Gauls.

The total length of the Aqueduct was 14 miles, and the fall for this distance was about 73 feet.

The channel-way was 6i feet high, by 3 feet wide, constructed with stone masonry and having an arch over the top : the interior face of the walls and the bottom was

covered with a coat of plastering ; 3 inches thick in the bottom, and 2 inches on the sides. From remains of this Aqueduct which are now found at various points along its course, it appears to have required many expensive structures for crossing valleys ; in one instance the Aqueduct bridge was 3,600 feet long, and the greatest height was 100 feet. In constructing the Aqueduct over these bridges, they formed it in two channels separated by a wall, and each covered with an arch ; thus they insured a supply of water across the bridge by one channel in case the other required repairs.

Aqueduct of B ourgas, near Constantinople.

Three Aqueducts exist in the valley of Bourgas, 8 miles

from Constantinople, for conducting water into the city. One of them is remarkable for the beautiful architectural arrangement and the solidity of its construction. It is 115

feet high, and was built under the Emperor Justinian, A. D. 527. It has two ranges of arches, one above the other, and the Aqueduct supported upon the second. These Aqueducts are in some parts unlike those of Rome, which were formed on a continuous line for many miles, with a regular inclination from the source to the city, but are interrupted by reversed syphons.