Copper is next in importance to iron as a metal of the useful arts, though it is used mostly in alloys. Its principal uses are:

(1) As the main constituent of most of the useful alloys.

(2) For pipes and tubes to convey steam and liquids. A coating of tin is frequently given copper pipes and tubes used to convey liquids to aid in resisting corrosion.

(3) As wire for resisting corrosion and particularly for electric conductors because of its high degree of conductivity when pure.

(4) For sheathing and fastenings of wooden ships.