Briare Aqueduct
The Briare Aqueduct in central France carries the Canal latéral à la Loire over the River Loire. It replaced a river-level crossing from the canal to meet the Briare Canal that was hazardous in times of flood. Between 1896 and 2003 it was the longest navigable aqueduct in the world, until the opening of the Magdeburg Water Bridge.
662 metres long. designed by the engineers Léonce-Abel Mazoyer and Charles Sigault.The masonry abutments and piers were completed between 1890 and 1896 by Gustave Eiffel and the steel channel was completed by Daydé & Pillé of Creil. The aqueduct was inaugurated on 16 September 1896. The aqueduct is built on fourteen piers. These piers support a single steel beam in turn supporting a steel channel which contains more than 13,000 tonnes of water, 2.2 meters deep and 6 metres wide allowing boats with a 1.8m draught to cross.
The above information is condensed from the Wikipedia entry.
See also Engineering 1894/11/30 and Engineering 1897/01/15