Today, we invent the city street. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
As a child, growing into an
awareness of the world around me, I was first
conscious of my room and my parents, then of my
house and the street in front. Next, I learned that
I lived on a grid. My personal coordinate was 852
Holly Avenue. To the west, Holly intersected
Victoria Street, to the east Avon.
So my measuring stick became the rectangular city
block. In the short dimension, a block was two lots
deep, with an alley splitting it down the middle.
(The alley was where horse-drawn wagons, then
trucks, made their deliveries.) In its long
dimension, a block held ten or twelve houses on
I grew older -- began walking, then biking, further
and further from home. I learned about miles -- one
mile was eight long blocks. And, to this day, and
no matter where I am, I find ways to interpret my
surroundings in terms of these old city blocks.
Of course, not everyone shares this
coordinate-system view of the world.
Nevertheless, a grid of city streets does pervade
much of our thinking. That's why an essay by John
Brinckerhoff Jackson got my attention. As Jackson
studies cities, he finds that streets were a major
stage in their evolution.
Early medieval towns were served by connecting
roads, but once in town, those roads blurred. Look
at old drawings of cities and what you see are only
the masonry structures -- towers and spires. Wooden
structures came and went. You see no streets.
Instead, a rabbit-warren network of footpaths is
buried within the city.
As cities grew, you began finding central market
sections, served by roads that extended into the
city. That change was driven, in turn, by the
development of horse harnesses.
For Romans, oxen had been the major
power supply for wagons and carts. It took a long
time for people to realize that ox har-nessing
strangled a horse's windpipe. We couldn't make full
use of the horse in drayage until we'd first
invented the horsecollar. But we still
just carried goods into and out of a city square.
One more invention was needed before we could make
use of a system of city streets within. That was a
swiveled front axle that allowed wagons to
negotiate tight turns.
By the thirteenth century, all that was in place.
And cities were growing to sizes that could no
longer be served by a single market area. Only then
were systems of streets finally created.
And so, by the time westward-moving America built
two new cities on the Mississippi -- St. Paul and
Minneapolis -- their form would naturally be a
clean rectangular grid of streets, almost from the
start. That's why a rectangular coordinate system
is so grooved into my Midwest consciousness --
horses in the alley, and cars on the street. (Even
then, when we moved into that old house, it still
had a concrete block on the front curb, to help
visitors descend from their carriages.)
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
J. B. Jackson, The Discovery of the Street. The
Necessity for Ruins and Other Topics, Amherst,
MA: The Univ. of Mass. Press, 1980, pp. 55-66.
I am grateful to Drexel Turner, U. H. College of
Architecture for providing the Jackson article.
Map of my childhood coordinate system. Image
courtesy of Yahoo.com
The Engines of Our Ingenuity is
Copyright © 1988-2003 by John H.