Today, we find a bicycle in the wrong place. 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.
I'm almost used to being
surprised by Leonardo Da Vinci; but I was really
astonished by an item that turned up in the
Codex Atlanticus. That's a collection
of Leonardo's drawings that someone pasted into a
scrapbook soon after he died.
Leonardo was fastidious about writing on both sides
of his paper. The man who made this scrapbook cut a
big square hole in each mounting sheet so you could
see both sides. Leonardo's students had practiced
on the back of some pages. No holes for them. The
student scribbles were permanently sealed off.
The scrapbook was dismantled during the 1970s. We
could finally see everything. Then the most
astonishing thing turned up. In 1504 Leonardo made
sketches on two of the pages while he was trying to
improve coastal defenses. Nothing special there.
On the back, student sketches: two pornographic
drawings and a mocking sketch of Leonardo's
favorite model -- a teenage boy, also a student.
Still nothing special. But there's one more item in
the upper right corner that you or I might hardly
notice. It's too familiar. It's a bike -- like the
one you rode as a kid.
It has two wheels of equal size -- with spokes. It
has pedals, a chain, and a sprocket. It has
Leonardo anticipated many things -- helicopters,
parachutes, tanks. Most were out of proportion.
They would never really have worked. This was
different. This one would've worked.
The development of the modern bicycle began in
1816. It took its modern form -- the form in
Leonardo's sketch -- around 1885. Very little has
changed since then. That odd sketch was pasted into
a scrapbook 300 years before the first 19th-century
bike. It was unpasted 90 years after such bikes
The sketch clearly had no connection with the
invention of the modern bike. Yet there it sits,
quite impossible, but there.
Who cooked up this machine? Leonardo or the
student? From what kind of thin air did it flow?
Leonardo gives a detail of that sprocket and chain
in another codex. We can be almost certain that the
student copied the bike from some lost Leonardo
You see, the bicycle was very hard to invent. The
concept of unstable two-wheeled motion didn't come
easily. This sketch hints that there might be one
optimal bicycle design, and that Leonardo thought
it up. It seems he really did create a design so
subtle that it took most of the 19th century to
reinvent it -- and that he did it entirely in his
head, without ever making the real thing.
That's almost too astonishing to believe. But we
have no better explanation for that crazy
anachronistic drawing -- suddenly spinning into our
world from the wrong, wrong, century.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds