The flames for processing the stones were provided by large dragons lying outside the factory, and having all the furnaces in one place like this made it far easier for the dragonborn to package and ship the processed dragonstone once they were done with processing!
Riyala had matured a lot in the time since she became the priestess of fire. Unlike the other priestesses who had spent most of their time in the Forest of Fire with the dragons and stayed away from the dragonborn so that they could rule themselves, Riyala felt it was her duty to take care of both the dragonborns and the dragons, and she was doing everything she could to make sure that her world progressed. Riyala's time on Earth had shown her just how primitive a lot of Radagan was. Radagan lacked infrastructure and innovation, and Riyala was going to do her best to take Radagan to the next level during her lifetime.
