Qu Dajun (1630–1696) on the iron industry in the province of Guangdong, ca. 1600

The text is one of 25 sections in Chapter 15, ‘Products’, in Qu Dajun’s book, ‘New discourses on Guangdong’, ca. 1680.

There is no better iron than Guangdong iron. In the iron-producing mountains of Guangdong, wherever there is yellow water seeping out, one knows there is iron. Digging there, one will find a large body of iron ore in the form of an ox. If one follows the path of the underground water and digs deeply, more iron will be obtained. However, of the mountains which produce iron, it is only on those which are forested that a furnace can be operated. If the mountain is bare, even if there is a great deal of iron it will be of no use. This is why ‘iron mountains’ are not easy to find.  . . .

There is a spirit in the iron ore, and to this the furnace-master must sacrifice devoutly before he dares to operate a furnace.

The furnace has the shape of a vase with its mouth upward. The breadth at the mouth is about a zhang [3.2 m]. The base is 3 zhang 5 chi [11.2 m] thick, and the height is half of that [5.6 m].  The thickness of the body is slightly more than 2 chi [64 cm]. It is built of ashes, sand, salt, and vinegar.  It is bound about with thick cane and braced with wood and is built against a mountainside for greater solidity.

Blast apparatus, detail from a drawing of an iron foundry, ca. 1334 (Ao bo tu, originally published 1334; reproduced here from an 18th-century copy).

At the back of the furnace is an opening, and outside the opening is an earthen wall. The wall has two ‘doors’ [blower fans]. Four persons operate these ‘doors’, alternately ‘closing’ and ‘opening’ in order to produce the force of the blast.

[A blast apparatus like this is shown in the picture.]

The two openings [the blast-hole and the tap-hole] are lined with ‘water stone’ [diatomit], which is produced at Dajiang Mountain [in modern Yunfu County]. Its substance is not hard, and therefore it does not ‘receive the fire’ and can endure long without altering [i.e. it is highly refractory]. 

Furnace operation begins in the autumn and ends in the spring.  . . . Iron ore mixed with charcoal is charged into the furnace, usually using a mechanical device. The flames from the furnace light up the sky, and its dirty black smoke does not disperse for several tens of li [1 li = ca. 0.6 km].

When the iron ore has ‘melted’ it flows out into a rectangular pool [i.e. pig mould] and solidifies into an iron slab.  . . .  In the twelve hours [24 modern hours] of the day, one slab should be produced each hour, with a weight of about 10 jun [180 kg]. If two slabs are produced per hour, this is called a ‘doubled cycle’; then the furnace is excessively vigorous, and in danger of damage. The furnace can be protected from damage by anointing it with the blood of a white dog.
 
An ironworks generally has 300 families living around it, providing services as follows: furnace tenders, more than 200; miners, more than 300; water-carriers and charcoal-producers, more than 200; pack animals, 200 oxen; freighters, 50 vessels. The capital investment of an ironworks totals not less than 10,000 taels of silver. If it produces more than 20 slabs per day it is profitable, while eight or nine slabs [per day] is unprofitable; this is a fundamental principle.

Of all the smelters the iron of Datangji Furnace in Luoding County is best. All of it is ‘first grade iron’, glossy and soft, and can be drawn into wire.  . . . It is more expensive than the first-quality iron of any of the other smelters.

The iron from all of the ironworks is shipped to the port city of Foshan, where the people are excellent founders.  . . . Woks from Foshan are expensive, because they are ‘hard’, and those of Shiwan [in modern Boluo County] are cheap, because they are brittle.  When they are sold as far away as central China, people can distinguish them by their thinness and smoothness; the foundrywork is refined, and the craftsmanship is accomplished.  . . . 

In Foshan there are several dozen iron-fining plants employing several thousand persons. Each plant has several dozen anvils and at each anvil there are more than ten persons.

Click on the image to see it enlarged.