stylistic:tone, structural:summarization
Aqueducts

His description of aqueduct construction includes the way they are surveyed, and the careful choice of materials needed, although Frontinus (a general who was appointed in the late 1st century AD to administer the many aqueducts of Rome), writing a century later, gives much more detail of the practical problems involved in their construction and maintenance. Surely Vitruvius' book would have been of great assistance in this. Vitruvius was writing in the 1st century BC when many of the finest Roman aqueducts were built, and survive to this day, such as those at Segovia and the Pont du Gard. The use of the inverted siphon is described in detail, together with the problems of high pressures developed in the pipe at the base of the siphon, a practical problem with which he seems to be acquainted.