—This metal is found in a pure state in large quantities around Lake Superior in the United States and in Chili, South America. It is a fairly hard metal of a reddish color, has a high luster, is malleable, and ductile.
Long before iron was known utensils and weapons for the chase and war were made of copper and copper tools have been found that were made by the ancients and tempered even as steel is tempered now, but the art was lost when iron came into use.
Copper is now largely used in the arts and trades as for the sheathing and bolts of ships, the conducting parts of electrical apparatus, in making alloys, such as bronze of which tin is the other metal. Copper is easily hammered and drawn but it is so tough that it is hard to saw and drill.
It does not oxidize in dry air but in moist air it gradually changes and takes on a layer of carbonate of copper which gives it a very beautiful and artistic appearance and makes it look as if it was a thousand years old.
Aluminum.
—This metal is found everywhere in nature but as it is never found free it is only in the last few years that it has been extracted in large quantities and cheaply enough to bring it into use.
It has a bright bluish white color nearly like that of tin and is the lightest common metal known.[19] It does not tarnish either in dry or moist air; it is malleable and ductile and as easy to work as brass but it is very hard to solder but there are soldering compounds on the market by which it can be soldered. Aluminum can be bought[20] in sheets of any thickness, or in rods or tubes of any size.
[19] Aluminum when mixed with magnesium makes an alloy called magnaleum and this is lighter than aluminum alone.
[20] Sold by the Aluminum Co. of America, 120 Broadway, N. Y.