Adds electric versions of the stone and steel furnaces, two upgrades of the electric furnace, and an electric boiler.添加石制熔炉与钢制熔炉的电动版本、电动熔炉的两种升级型号，以及一款电锅炉。我不会修改程序所以只是换了两个贴图。
Tweaks
Mod category: Tweaks
Small changes concerning balance, gameplay, or graphics.
