The lower levels of the pyramid must also grow-for more people to consumer higher-end items, there must be more people to make those items.
A high pressure area is an area where the air sinks. As it does, it warms up by the adiabatic effect of a greater pressure and that causes the clouds to evaporate, giving place to a clear sky
The answer is mineral deposits
You would go through these is this general order:
Palaestra- exercise room, socialization, preparation for baths basically
Apodyterium- changing room, to get... changed?
Tepidarium- warm bath room, spend time sitting in a warm room. Prepare for the next room
Caldarium- hot bath room, hot water to soak in. After that slaves come rub you down with olive oil (soap was not invented yet)
Frigidarium- cold plunge bath, rinse down the oil with cold water
All hot room were heated by hypocausts, a way of hot air circulating through walls and beneath the floors
tada
Because the way that they stand and are
