铜　 镜     tóng jìng      

The bronze mirror, like its modern glass counterpart, was a household article of daily use in which to look at oneself. Its obverse side is so smoothly polished that it can reflect the image of the user's face. The reverse side is often cast with a knob and decorations, so it is also an art object. Most of the authentic bronze mirrors are finds from ancient tombs; some have been handed down from generation to generation in old families. 
   Our ancestors started to use bronze mirrors in as early as the 11th century B.C. During the Warring States period, bronze mirrors prevailed among the populace. The front side of the mirrors, after being polished, glistens while the backside is embellished with single-layered or double-layered patterns, among which the commonly seen are those of animal faces, flowers and leaves, dragons and phoenixes.
   During the Western Han period, the bronze mirrors used to be relatively thick and heavy. Most of the decorative patterns were of geometrical forms, supernatural figures, or fowls and animals, accompanied by inscriptions of only three or four characters with such meanings as "eternal love", "never to forget", "wealth for ever" and "everlasting happiness". The content frequently dealt with common well washings. 
   During the Song and Yuan Dynasties the bronze mirrors appeared in all shapes: round, rectangular, rhomboidal, octagonal, and those with a handle. Since the Qing Dynasty, however, the bronze mirror has gradually given way to the glass mirror.
   In Shanghai Museum, one finds a treasure of the Western Han period, the "penetrative bronze mirror", and measuring 11.5cm in diameter. Like ordinary bronze mirrors it bears patterns and inscriptions on the back. But what amazes people is that when a bundle of rays is projected onto the surface of the mirror, which, in turn, reflects the light on the wall, the pattern and inscriptions on the backside are shown in the ring of the light, as if they had penetrated the whole thickness of the mirror. Hence the name of the mirror. For a long time in the past, even scientists were so puzzled at the phenomenon that it was called a "magic mirror". Today, reproductions of this mirror are being made and sold as souvenirs and they appeal very much to tourists.