The exhibitions of this museum begin with an illustration from a Han-dynasty brick that was excavated in Sichuan. The illustrations on the brick depict the salt industrv of the Han period and show in a lively and realistic manner the stages of

salt production. Wide-mouthed shallow wells were used for early production; a two-story building and four men on the brick show how briny water was brought by conduits to heating units that cooked out the water and resulted in pure salt.

 

By the time of the Song dynasty, Chinese craftsmen had invented special tools for digging small-mouth-diameter wells. Not only was the mouth of the well sometimes 'as small as a small bowl' but it was dug down very straight into the earth. The tools for allowing this well-tunnelling method are recorded in the 'Dongpo Forest of Stelae,' also exhibited at the Museum.

 

By the time of the transition period between Ming and Qing dynasties, the depth of these so-called Zhuotong wells reached three hundred zhang, a zhang being 3 1/3 meters, or around 1,000 feet. This museum has in its collections a relatively complete set of well-digging tools, that not only could dig deeply but ensured that the well's cavity would be straight. Some modern-day well-digging technologies are a result and a continuation of this historical foundation.

 

Joseph Needham (Cambridge University Professor, 1900-1995, Englishman, a world-famous historian of science and technology) listed more than twenty important inventions that had entered Europe from China in his 'History of Science and Technology in China.' The fifteenth of these was the deep-well drilling technology. It is on display and well worth seeing in this unusual museum.