Assertion: blast furnace | /r/CreatedBy | the han dynasty
Facets:
value: in the 1st century ad
type: TEMPORAL
Source sentences:
text: Although cast iron farm tools and weapons were widespread in China by the 5th century BC, employing workforces of over 200 men in iron smelters from the 3rd century onward, the earliest blast furnaces constructed were attributed to the Han Dynasty in the 1st century AD.