ot change even when in
the open air for ages. That is one reason why it has always been so
much used for statues. There are two strange facts about this mixture.
One is that bronze is harder than either copper or tin. The other is
that if you mix one pint of melted copper with one pint of tin, the
mixture will be less than a quart. Just why these things are so, no
one is quite certain. Mathematics declares that the whole is equal to
the sum of its parts; but in this one case the whole seems to be less
than the sum of its parts.

Another reason why bronze is so much used for statues is that the
castings are smooth. I once went to a foundry to have a brass ornament
shaped somewhat like a cone made for a clock. The foundryman formed a
mould in clay and poured the melted brass into it. When it had cooled,
the mould was broken off and the ornament taken out; but it was of no
use because it was so full of little hollows that it could not be made
smooth without cutting away a great deal of it. The man had to try
three times before he succeeded in making one that could be polished.
If it had been made of bronze, there would have been no trouble,
because bronze, hard as it is after it cools, flows when it is melted
almost as easily as molasses and fills every little nook and corner of
the mould.

A famous Latin poet named Horace, who lived two thousand years ago,
wrote of his poems, "I have reared a monument more lasting than
bronze"; and he was right, for few statues have endured from his day
to ours, but his poems are still read and admired.

Bells are made of bronze, about three quarters copper and one quarter
tin. It is thought that much copper gives a deep, full tone, and that
much tin with, sometimes, zinc makes the tone sharp. The age of a bell
has something to do with its sound being rich and mellow; but the
bellmaker has even more, for he must understand not only how to cast
it, but also how to tune it. If you tap a large bell, it will, if
properly tuned, sound a clear note. Tap it just on the curve of the
top, and it will give a note exactly one octave above the first. If
the note of the bell is too low, it can be made higher by cutting away
a little from the inner rim. If it is too high, it can be made lower
by filing on the inside a little above the rim. Many of the old bells
contain the gifts of silver and gold which were thrown in by people
who watched their founding. The most famous bell in the United States
i