The most distinct feature of a cannon is that adding it to a wall significantly boosts the defensive capability.
[Flame Furnace: Stone Brick 1200, Fine Stone Brick 800, Cast Iron Block 520, Fine Iron 120, Metal Parts 1500, Red Flame Essence 3, Traces of Wind 2, Gray Iron Stone 5.]
(Description: A massive furnace constructed by Dwarves, the Flame Furnace undertakes 80% of Dwarf forging work.)
A purple blueprint of the furnace.
The single orange large furnace on Eight Peaks Mountain is hard-pressed to handle the workforce of the entire race.
But, the Flame Furnace shoulders a majority of the forging work.
It could be considered as an upgraded version of the furnace.
[Wind-breaking Crossbow Cart: Tough Wood 850, Ironized Wood 520, Cast Iron Block 220, Metal Parts 800, Precision Parts 200, Traces of Hurricane 2.]
(Description: A rapid-fire crossbow cart produced by Dwarves. Its massive power, fast firing rate, keeping even dragons at bay.)