Heated Furnace
A new furnace that can be powered in various ways.
Place furnaces
Stone wasn’t cutting it anymore. You already had a myriad of Furnaces, but they were getting hard to manage. You just wanted something that could take more Coal at once, but what you got was something totally unexpected.
By surrounding a Furnace with Iron Ingots, you completely got rid of the fuel slot. Oops.

However you were not to go down beaten and since you already know of the energy transmitting capabilities of Iron you’re convinced you can make something to power this Furnace... You decide to place it in the world and see if you can think of something