Measures and Weights
The traditional Chinese unit for length is chi; for capacity and volume, is dou; and for measurement of weights, is cheng, or the steelyard.
The length, capacity and weight, being the measure of commercial exchange even in early human history, have become fairly completed as a fair, equitable standard and managerial system as early as the Shang and Zhou Dynasties more than 3,000 years ago. Though the measuring units varied in different dynasties, the system of length, capacity and weight, as a basic calculating standard in commercial activities, has been carried on ever since to today.
The system of length, capacity and weight has been a rule of fair and honest conducts in commerce and trades. The use of the so-called "gradation mark" on a steelyard is that when the pan of the steelyard is empty, the sliding weight is placed on the gradation marked on the beam of the steelyard, and the cord on the beam is lifted, the beam must be balanced, which means the steelyard is a "fair" one. Otherwise an inaccurate mark of the gradation leads to short-weights to the customers. A good steelyard should stand up against the most careful checks. The beam, sliding weight, hook, lifting cord, gradation mark are all required to be strictly in accord to the standards without any error. All of these come together promises the commercial honesty and credit of a good steelyard: fair, equitable and open. The saying, "buy with large dou and sale with small dou" describes the cheating in commercial activities by using the vessel, whose standard is changed.
As the society progresses, the system of measures and weights has also become a part of the social moral codes, and has combined with commercial honesty and credit, serving to maintain the stability of the society. An old trade name is a sign that guarantees its credit in commerce and trading. It includes three aspects as credit, good faith and reputation, the latter two mainly belong to the realm of social morality.
Collected from: Tibet, Yunnan, Gansu, Ningxia, Henan, Hebei, and Beijing.
Time span: Qing Dynasty to the Modern Times, about 400 years.