Not water, but a load of hot air!
This photograph shows part of the hypocaust (underfloor heating system) at Folkestone Roman Villa.
A charcoal furnace was lit by a slave on the far side of the arch.
Hot air from the furnace passed through the arch and between the columns, heating the floor above (now missing).
This villa had all mod cons, the height of Roman sophistication.
This photo was taken in 1924, shortly after the villa had been excavated by archaeologists.
