In some parts its course has been excavated through hills ; but near to Lisbon it is carried over a deep valley, for a length of 2400 feet, by means of several bold arches, of which the largest has a height of about 250 feet, by a breadth of 115. The arches being pointed have an interesting aspect, particularly when viewed from below, the interior of the spacious vaults being not only majestic in appearance, but reverberating every sound. The water flows through a stone tunnel, or covered arch-way, about 8 feet

wide, formed in the middle of the structure ; and on each side there is a foot-path, with a parapet wall, having a sufficient width for two persons to walk. The Aqueduct enters the town on its northern side, at a place called da Amoreira, where it branches into several others, in order to supply the different fountains, from which the inhabitants are supplied. Persons, denominated gallegos, obtain a subsistence by selling the

water, which they procure at the fountains in small barrels, and afterwards cry it through the streets.

Aqueducts of Mexico and the adjacent States.

The people who, in remote times, inhabited the region of Mexico, were advanced in civilization and in the arts ; they had regularly organized states and established forms of government, and their immense cities, their roads, Aqueducts and other public works, give evidence of the advanced state of the arts among them and their knowledge of the sciences.

The location and great population of some of their cities required a familiar knowledge of hydraulic operations to supply them with water ; and hence it would seem as if they had cultivated this department of the arts equally with others, for some of their Aqueducts were of a character that would