Incense burner, Indian, 1801-1900.
© Science Museum / Science & Society Picture Library
An incense burner in the form of a fish, made of a copper alloy. Incense is made of an aromatic gum or spice, which produces a fragrance when burned. It is often used in religious ceremonies. Here, the hinged body of the fish-shaped burner is made of metal mesh, to allow the substance to be inserted and the perfume to escape. Pure copper is difficult to cast. As a result it is usually alloyed with tin, zinc, aluminium, lead and nickel. An alloy of mainly copper and zinc is called bras, whilst an alloy of copper and tin is called bronze. Alloys of copper and aluminium and copper and nickel are called aluminium bronzes and cupronickels, respectively. Lead is often added to improve the machining properties.