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The first main area is the field of engineering. Within this
chapter, the development of iron and steel is the greatest
achievement. The development of iron and steel led to other advances.
By at least the 4th century the Chinese have developed blast furnaces
to obtain cast iron from iron ore. This was 1200 years before the
first blast furnace showed up in Europe. The reasons that the author
gave to explain the reasons why the Chinese developed this technology
are simple. The Chinese had access to large amounts of clay, the key
ingredient in making blast furnaces. The Chinese also figured out
that by adding a substance they called ”Black Earth,” they could lower
the melting point of iron.

Another major invention of the Chinese, that led to other
achievements, is steel. The common belief today is that Henry Bessemer
discovered the process of refining iron into steel. The fact is
Chinese had developed the process to refine iron into steel in the
second century BC The Chinese learned that by injecting oxygen into
the blast furnace, they could remove the carbon from the iron. The
Chinese called this process the “hundred refinings method” since they
repeated the process that many times. The finished product was highly
prized in China for its strength and ability to hold an edge on a
sword. The Chinese would weld the steel onto weaker iron thus creating
a strong edge and a superior weapon. The Chinese iron and steel
workers were the best at making different types of metals into modern
times. But then, no one else could have done so at the time, since
iron existed nowhere else but in China.