铜比钢铁要好得多，不会锈得过于严重，耐磨等特性；相对于黄金来说，铜的熔点低，铜水流动性好，易于铸造成型，而且价格也低的多。

Compared with gold, copper has low melting point, good fluidity of copper water, easy casting, and low price.

紫禁城的建设者们对防火特别重视，铜大缸1.2米口径单价，在宫殿前设置了这些大缸，称之为“门海”。门海即门前的“大海”，门前有了“大海”，以水克火，砖木结构的故宫就不怕火灾了。因此，这些大缸又被称作吉祥缸。

The builders of the Forbidden City paid special attention to fire prevention. The copper VATS with a diameter of 1.2m were set in front of the palace, which was called "Menhai". The gate sea is the "sea" in front of the gate. If there is a "sea" in front of the gate, water can overcome fire. The palace museum with brick and wood structure is not afraid of fire. Therefore, these vats are also called auspicious vats.

铜雕大缸在古代占据很高的地位。在故宫中，大殿前、庭院中都有摆放大铜缸，这些铜雕大缸是雕塑工艺中的一种铸铜雕塑，腹宽口收，容量极大，而且装饰精美，两耳处加饰有兽面铜环，据说，这些大铜缸雕塑是用来防火的，因故宫中的主要建筑材质以木质为主，很易引起火灾，而在通常在门口的铜雕大缸中注满水，以备不时之需。但是这些铜雕缸实际存在的意义不仅局限于消防，

Bronze VAT occupies a very high position in ancient times. In the Forbidden City, there are large-scale copper tanks placed in front of the palace hall and in the courtyard. These large copper tanks are a kind of cast copper sculpture in the sculpture process. They have a wide belly, a large mouth, a large capacity, and are exquisitely decorated. The two ears are decorated with copper rings on the animal face. It is said that these large copper tanks are used for fire prevention. Because the main building materials in the Forbidden City are mainly wood, it is easy to cause fire. However, they are usually at the door In case of emergency, the large bronze vat of is filled with water. But the actual significance of these bronze tanks is not limited to fire fighting,