Magic stone cannon artilleries made of metallic steel rock were a concept that Eleanor told Saleen about. In the end, the prototypical magic stone artillery cost a total of more than one-million gold coins, from design to producing it.
They went through the entire process a few times. Initially, mages crawled into the cannon to put the magic arrays in place. In the end, they created a tool to put the magic arrays directly in the cannons. After a few rounds of trial and error, the magic stone artilleries were finally ready to be mass-produced. Nevertheless, the cost of producing them remained high.
If the intention was to guard key areas, then alchemy crossbows wielded by skilled archers would have been more appropriate. If the magic stone artilleries were used to attack within short intervals, their magic arrays would become unstable very easily.
