Today, we say goodbye to lighthouses and cabooses.
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.
Remember railway train
cabooses, those moving rear-observation towers that
let an observer view the whole train? Electronic
safety systems have made them obsolete. But
cabooses are so woven into the fabric of
railroading that, in 1980, railways were caught in
a bitter debate as to whether they should be
abandoned.
It's
that way with lighthouses as well. Lighthouses call
up the romance of the sea just as powerfully as
cabooses complete the image of railroading in our
mind's eye. Lighthouses are used to mark all kinds
of dangers to shipping at night -- sea-crossings,
rocks, major landfalls. The distance from the light
to the horizon depends
on how high the lamp is, so height is
important. A fifteen-foot light is visible four and
a half miles away. A 120-foot light is visible for
over twelve miles, and so forth.
That's why the Pharos at Alexandria was so large.
One of the Seven Wonders of the Ancient World, it
held a huge bonfire 400 feet in the air. And, like
it, lighthouses down through the centuries have
usually been tall masonry towers mounted on shore,
or maybe on shoreline cliffs, burning wood or olive
oil and later, coal or candles. It was, for a long
time, a static technology. Rotating beams weren't
invented until 1611. It was 1763 before reflectors
were finally put behind lamps to boost their
intensity. Lenses were introduced a scant two
hundred years ago.
Lighthouse construction started moving again in
1698 when the English had to warn ships away from
the Eddystone rocks, fourteen miles southwest of
Plymouth. If you know about that lighthouse, it may
well be because you've heard the old folk song:
Oh, me father was the keeper of the Eddystone
Light,
And he slept with a mermaid one fine night.
And from this union there came three,
A porpoise and a porgy -- and the other was me.
Well, building the Eddystone light was a terrible
job, and it greatly advanced the whole technology.
It had to be erected right at sea level, where
construction was hammered by waves. The first one,
made of wood, lasted five years. The next, made of
wood and iron, burned down after 47 years. The
great engineer John Smeaton erected the third
Eddystone Lighthouse in 1759. He used a new kind of
interlocking stone construction that lasted until
1881.
But now radar, sonar, and electronic buoys are
putting an end to lighthouses. Henceforth, you and
I will live in a world without cabooses on trains,
and without those beautiful storm-beaten minarets
to call the weary sailor home.
The siren attraction of the lighthouse, like any
good technology, is that it did a fine job of
fulfilling human need. That's why it seems to reach
far beyond function and to express something inside
us. All good technology holds symbolic as well as
functional power. That's why we're so loath to say
good-bye to lighthouses -- or, for that matter, to
railroad cabooses.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
