e wheel, pries them out of the mould and drops them
into water. Then by the aid of the fingers of a machine and those of
men, they are loaded upon cars.

In copper there is often some gold and silver. The precious metals do
not make the copper any better, and if they can be separated from it,
they are well worth the trouble. This is done by electricity. It is so
successful that the metallurgists are hoping soon to take a long step
ahead and by means of electricity to produce refined copper directly
from the ore. Indeed, this has been done already in the laboratories,
but before the managers of mines can employ the method, a way of
making it less expensive must be discovered.

No mine that wastes anything is as well managed as it might be; and
superintendents are constantly on the watch for cheaper methods and
for ways to make the refuse matter of use. Even the scoria, or slag
from the furnaces, has been found to be good for something, and now it
is made into a coarse sort of brick that for certain rough uses is of
value. By the way, the shaft of a copper mine, the Red Jacket, has
shown itself of use in a manner that no one expected, namely, it helps
to prove that the earth turns around. This shaft is the deepest mining
shaft in the world, and when you get into the cage, you go down a full
mile toward the center of the earth. If you drop any article into the
shaft, it always strikes the east side before reaching the bottom. The
only way to explain this is that the earth turns toward the east.

Copper mixed with zinc forms brass, which is harder than copper alone.
It tarnishes, though not so easily as copper; but a coat of varnish
will protect it till the varnish wears off. A good way to find out the
many uses of brass and to see how valuable they are is to go along the
street and through a house and make a list. On the street you will see
signs, harness buckles, and buttons, everywhere. Look on the
automobiles and fire engines for a fine display of brass, polished and
shining. In the house you will find brass bedsteads, curtain rods,
faucets, pipes, drawerpulls, candlesticks, gas and electric fixtures,
lamps, the works of clocks and watches, and scores of other things.
You will not have any idea how many they are till you begin to count.

Copper mixed with tin forms bronze. Go into a hardware store and look
at the samples of bronze outside of each drawer, and you will be
surprised that there are so many. Bronze does n