After multiple rounds of purification, the Earth fire becomes quite stable. It can even be comparable to Charcoal Fire.
Speaking of Charcoal Fire, it is necessary to introduce it.
Charcoal Fire comes in various types; the worst is Charcoal because the temperature is limited, reaching at most about 700 degrees Celsius. Moreover, it burns out quickly. New charcoal needs to be continually added to the furnace.
Adding new charcoal will inevitably lead to unstable fire temperatures.
The people of this world are very clever; after many generations of effort, they have invented a bellows. By blowing air, it makes the charcoal burn more quickly and solves the problem of unstable temperatures.
The majority of penniless Pill Masters or half-baked Alchemy Apprentices build bellows in their own homes and set up a furnace for Alchemy.
This is also the cheapest way to perform Alchemy.
