manner, and were inserted in the wall of another receiving reservoir. This receiving reservoir differed from the emitting one only in this, that it held the waters flowing towards the bottom of its basin, and the emitting one poured them out from the upper part, about three feet from the bottom, so that while the water rose in the emitting reservoir to three or four feet, that in the receiving one would not rise more than two feet. The nine leaden pipes through which the water flowed, had each eight inches diameter in the clear ; the thickness of the lead of which they were composed was about one inch.

Delorme also mentions a circumstance in this syphon aqueduct, which has given rise to much discussion among those who have examined the subject ; he states that these syphon pipes, after having descended about 75 feet, each divided itself into two branches, and that thus the waters are carried the rest of the course over the bridge in eighteen pipes, and until they rise again, on the opposite side, to a height of about 70 feet, at which point they are again united, arid the waters pass on, and enter the receiving reservoir in nine pipes.

In opposition to this opinion of Delorme, another eminent architect, who examined the aqueduct, thought that the receiving and emitting reservoirs had the same number of

pipes, and that the nine pipes which proceeded from the one to the other, preserved the same dimension throughout. Delorme says that the water in the emitting reservoir, was higher by one foot than that in the receiving one but Mr. Villar, a man of science, resident at Lyons, took the ;