21. `Exploring the soil' (tan tu).Figures 21-28. The first eight of twelve watercolours in an album preserved in the Bibliothèque Nationale, Paris (`Fer', C.E. Oe 119 in-4to., 1-8).
21. `Exploring the soil' (tan tu).
22. `Testing the iron [ore]' (yan tie).
23. `Extracting the iron [ore]' (qu tie).
24. `Separating the lead' (fen qian). This picture clearly shows the calcining of iron ore; the idea that lead is somehow involved is curious.
25. `Purifying the dirt' (qing ni). The `dirt' is the calcined ore.
26. `Removing the fire' (chu huo). This probably shows the slag
from the blast furnace being disposed of. The water-colour has been reproduced
in colour by Hauser (1974, p. 21).
27. `Tipping out the iron' (dao tie).
28. `Making bars' (zuo tiao).