Ballista, scorpio exist only in re-enactments and are far from the functionality of the originals. The originals required human hair, it was the springiest, had

Ballista, scorpio exist only in re-enactments and are far from the functionality of the originals. The originals required human hair, it was the springiest, had to be processed very particularly and it's very labor intensive to recreate, so re-enactors have not. Their historical range is ~400 meters, replicas do ~150. Complicated specialized tech made in large urban populations is the place to look. Many things went extinct only to be reinvented once large urban populations arose again. But sometimes there was alternative technology, people did not remake the ballista because there were guns by the time urban populations bounced back in Europe. Greek fire, Roman concrete, Egyptian concrete lost and reinvented. Damascus steel - exact process lost, Japanese made something similar. Egyptian block built ships are lost http://www.pbs.org/wgbh/nova/ancient/building-pharaohs-ship.html http://www.pbs.org/wgbh/nova/ancient/building-pharaohs-ship.... but ships for the same purpose were reinvented and drastically better. We don't use large wooden ships today, except for re-enactments. Siege towers not used, city walls not built, but we have tanks and trenches. So it depends on how you categorize it. Functionality of tools remains, but some specifics are drastically different, so it gets subjective.