Today, let's talk about an oddly static technology.
Let's talk about locks. 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.
This bit of doggerel is, maybe, 400
years old. It says a lot about locks and the way we
relate to them. Ask most people what a lock means to
them and they'll tell you, "Security." Yet which of
us wants to own a lock that can't be picked, in a
A zealous Lock-Smith
dyed of late,
And did arrive at heaven gate,
He stood without and would not knocke,
Because he meant to picke the locke.
The locksmith in the poem craves the reward of
having cracked the very vault of Heaven. And we're
reminded that locks are also metaphors for human
ingenuity. After we think of security, our mind
leaps next to the puzzle of opening the lock.
Egypt made the first locks 4000 years ago. They
used wood. They also used a system of pins moved by
a key -- not all that different from modern locks.
For four millenia, locks have been less a work of
raw invention than of endless innovation.
The Greeks made metal pin locks, but they also
challenged human ingenuity with another system
entirely. Do you remember Alexander the Great
cutting the Gordian knot? Well, many Greeks devised
knots that only they could tie. Then they simply
lashed their doors shut. Of course Alexander showed
what any home-owner knows today. The locks on our
doors only slow criminals down. They seldom keep a
really determined thief out.
Medieval locks were wonderfully ornate on the
outside, but they stayed fairly simple on the
inside -- more status symbols for the wealthy than
solid protection. The big shift in lock-making came
after 1800. Once we began manufacturing with
interchangeable parts, we took lock-making away
from locksmiths and gave it to factories. Now
anyone could afford a lock.
The people who created the lock design that took
full advantage of the new system of manufacturing
were Linus Yale, Sr. and Linus Yale, Jr. By 1860
they'd perfected the convenient pin-cylinder lock.
Soon after that, a would-be poet could write,
Of course the Yale lock, secure as it
is, can be picked once you know how. Even so, the
most important developments in mechanical lock design
in recent years are still variants on the Yale lock.
You gave me the key to your heart, my
Then why do you make me knock?
"Oh, that was yesterday; Saints above,
Last night I changed the lock!"
Now we threaten our 400-year-old lock metaphor with
entirely new devices. We've invented electric locks
that we key with memorized numbers -- or our palm
print. The key question (pun intended) is, "Will
the old mechanical lock outlast our generation?" It
isn't just a simple device that's under assault. It
is, in fact, one of our most powerful mechanical
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds