Today, we wonder how people measured sound a
hundred years ago. 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.
An American professor named
Le Conte went to an evening gathering -- one that
was typical in the 19th century. It was a lamplit
musical party. He wrote about it in the 1858
Philosophical Magazine:
Soon after the music began, I observed that the
flame exhibited pulsations that were exactly
synchronous with the audible beats. This ...
phenomenon was very striking, [especially] when the
strong notes of the 'cello came in. It was
exceedingly interesting ... how perfectly even the
trills ... were reflected on the sheet of
flame.
Today we're so suffused with
microphones, amplifiers, and oscilloscopes! It's hard
to imagine a time when the study of sound wasn't
equipped with high-tech electronics. Victorian
scientists had nothing of the kind, and it's
fascinating indeed to see the brilliant down-to-earth
tactics they used to do what is now so easy. And so
it was that the observant Le Conte -- his mind
divided between music and physics -- seized on this
new means for diagnosing sound.
One man in particular had a special genius for that
kind of observation -- an Irish physicist named
John Tyndall, born in
1820. He started out as an engineer developing
railway equipment, but eventually earned a
doctorate in Berlin. He came back to London to
teach at the Royal Institute and to study the
physics of sound and light.
Tyndall's book on sound shimmers with highly-honed
mechanical means for displaying sound. He develops
Le Conte's observation into an 18-page section
called "Sensitive Naked Flames." Tyndall uses
flames to measure pitch and tone quality. At one
point he reads Spenser's
lines to a flame, from across a room:
Her ivory forehead full of bounty brave,
Like a broad table did itself dispread;
For love his lofty triumphs to engrave
And write the battles of his great godhead.
And as he reads, he watches how the
flame dances to the different vowel sounds.
He reflects light from tuning forks onto moving
paper. He gazes at the effects of sound on water
jets and shallow sand. There seems no end of
stratagems. And they're all so direct and palpable.
We finally close Tyndall's book -- this wild
intermingling of music, phenomena, and poetry --
and we come back to our clean digital recordings.
We come back to the 20th-century spawn of Le
Conte's and Tyndall's work. Yet it would be a
mistake to come all the way back. We can't afford
to forget that we were brought here by this
intimate weaving together of our minds and our
senses.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
