Technology
The ancient Romans also had a complex system of aqueducts, which were used to transport water across long distances. The first Roman aqueduct was built in 312 BCE. The eleventh and final ancient Roman aqueduct was built in 226 CE. Put together, the Roman aqueducts extended over 450 kilometers, but less than seventy kilometers of this was above ground and supported by arches.
Roman aqueduct
During the fall of the Roman Empire, some aqueducts were deliberately cut by enemies but more fell into disuse because of deteriorating Roman infrastructure and lack of maintenance, such as the Eifel aqueduct ("pictured right"). Observations made by the Spaniard Pedro Tafur, who visited Rome in 1436, reveal misunderstandings of the very nature of the Roman aqueducts:
During the Renaissance, the standing remains of the city's massive masonry aqueducts inspired architects, engineers and their patrons; Pope Nicholas V renovated the main channels of the Roman "Aqua Virgo" in 1453. Many aqueducts in Rome's former empire were kept in good repair. The 15th-century rebuilding of aqueduct at Segovia in Spain shows advances on the Pont du Gard by using fewer arches of greater height, and so greater economy in its use of the raw materials. The skill in building aqueducts was not lost, especially of the smaller, more modest channels used to supply water wheels. Most such mills in Britain were developed in the medieval period for bread production, and used similar methods as that developed by the Romans with leats tapping local rivers and streams.