The origin of the bellows

The earliest instruments used for forced air blowing were fans and blowpipes. Ancient Egyptian goldsmiths once used blowpipes with pottery nozzles. The Incas sometimes used 8 to 12 copper pipes to blow at the same time. Later, the air blast bag made of animal skin was invented. The two ends of the bag were equipped with air ducts and piston air inlets controlled by the operator. This simple blower is still used in some areas in modern times. The murals of the tomb of Rekhmir (ca. 15 centuries BC) of the Eighteenth Dynasty of Egypt include images of pot-shaped foot blowers. When the air is entering, the operator pulls up the leather bag with a rope, then steps on it to blow the air into the furnace. Each furnace is equipped with four blowers, and two people operate facing each other.

The gong (also known as the gong) is a kind of wind blower; the gong is a wind bag made of cowhide; the gong originally refers to a wind instrument with a mouthpiece, but in words, it is a metaphor for a wind pipe. According to historical records, it has existed since the Warring States Period. "Laozi Tao Jing" uses the metaphor of space "between heaven and earth, is it like a raft? It is empty but not yielding, and it becomes more and more when it moves."

There are many references to the hook in the literature of the Han Dynasty; the iron-making stone portrait of the Han Dynasty unearthed in Teng County, Shandong Province contains a picture of the hook. It has three wooden rings, two round plates, and is made of leather. When the leather basket is opened, the air enters the basket through the air inlet valve; when the leather basket is compressed, the air in the basket enters the air duct through the exhaust valve, and finally enters the smelting furnace. The iron-smelting technology of the Han Dynasty developed significantly, which was closely related to the improvement of the power of the gong. The blower itself is a leather paddle, probably dating from the Tang and Song dynasties.