the original floor, part of which consists of the paved base of the Via Appia that crossed it on one side.

Fondi: remarkable Roman walls with large towers. The chessboard plan of the town follows the Roman one. Here, as in Terracina, the Appia crossed the city. There are also notable medieval monuments including the castle of the Caetani and the Colonna. The current road perfectly follows the ancient one up to the Valle di Sant'Andrea. The original stretch of the Appian Way (Corso Appio Claudio) is underneath the present day street, so as you walk along it you'll be walking on top of an important piece of history.

If one wanted to cover the entire Appian Way in Lazio, continuing on to Formia and Minturno -visiting Cicero's tomb inmeasuring apparatuses, a diversion passage having an inverted U shape in which two adjacent, parallel channels are linked by a curved portion is installed inside an airflow channel. Thus, the overall length of the diversion passage is increased, reducing surges inside the diversion passage resulting from surges in the flow of air inside the airflow channel. In addition, the curved portion of the diversion passage and a downstream passage of the diversion passage are formed into a shape that suppresses contracted flow arising downstream from the curved portion. Thus, flow rate measuring precision is improved by suppressing decreases in flow velocity due to contracted flow to maintain flow velocity inside the diversion passage even in the low flow rate regions. 
However, in conventional air flow rate measuring apparatuses,