Today, some very-old bells with a surprising secret. The
University of Houston's College of Engineering presents
this series about the machines that make our civilization
run, and the people whose ingenuity created them.
Just after 1900, archaeologists
began finding curious sets of bronze bells in tombs
throughout China. They ranged from two thousand to
thirty-six hundred years old, and they looked like
truncated cones that'd been slightly squashed. They're
shaped a lot like our cow-bells, but these had no
clappers. They were struck. They're called Zhong
bells and, though thousands had been found by the late
1970s, they had yet to reveal their secret.
Players from China's National Music Research Institute
almost caught on when they did concert on a set of these
bells in 1957. They were working on a piece with the
unpromising title The East is Red, when they
were dismayed to find one of E-bells missing. Then a
player chanced to notice he could get that E by striking
the C-bell on its side. The C-bell apparently just
happened to give two tones, a third apart.
Twenty years later, as Chinese musicologists examined a
set of these bells, they realized that every bell in the
set did that. They all gave two tones, either a third, or
a minor third, apart. In fact, a closer look revealed
that many bells even had marks on the side where you
should strike to get one note or the other. Every bell
was, in fact, two bells in one.
The importance of that discovery
grows when we realize that it took the West a thousand
years to develop the cathedral bell, and we didn't have
it until the middle ages. Bells are very hard to make,
yet China had these remarkably sophisticated Zhong bells
during the Golden Age of Athens. The bells produce a rich
tone, they take far less bronze to get it than a
cathedral bell, and then they deliver two sounds for the
cost of one.
Acousticians are just now coming to understand how they
work. Musicians are finding they were really quite hard
to play. This high technology (which also took the
Chinese a thousand years to perfect) died out completely
during the Han period -- about the time of the first
Once historians began piecing the record together, they
realized these strange bells played a role beyond
music-making. For consistency of tone, they were all
tuned against a standard string. The consistency of their
shape made them a standard of volumetric measure. The
amount of bronze in each was so carefully controlled as
to provide weight standard. Each set of bells was a
mini-bureau of standards in ancient China.
The greatest delight of science, or
of history, occurs when an object or an event seems to be
one thing, turns out to be something else entirely. We
gazed at those remarkable, and seemingly unassuming,
bells for eighty years before they revealed dimensions of
sophistication we hadn't imagined. It makes me think of
Isaac Newton hearing an apple
fall in his back yard. Only an apple -- a common,
completely uninteresting, apple.
I'm John Lienhard, at the University of Houston, where
we're interested in the way inventive minds work.