Xu Xin forged some more steel and handed it over to Li Wenxi. At the same time, he also gave Li Wenxi some coal.
According to his earlier observations, a piece of coal (green) can keep the furnace burning for one hour, which is shorter than the burning time of a piece of green wood.
However, coal is easy to obtain. He doesn't know how long that pile of coal mine will take to be mined, and every time he swings the pickaxe, he can get a dozen or twenty pieces, which is much easier to obtain compared to a green tree that only yields five pieces of wood.
The most important thing is that coal can improve furnace efficiency.
"This is coal!" Li Wenxi was pleasantly surprised. "It can actually enhance furnace efficiency! Did you find a coal mine?"
"Yes, it's near my treehouse, buried about five or six meters underground."
