Today, the U.S. census points us toward the
computer. 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.
We ran our first census in
1790. Agents went door to door, asking four
questions. How many in this house are free white
males over 16? How many are free white males under
16? How many are free white females? And how many
are slaves or other persons? Those agents counted
just under four million people.
That number had risen to forty million by 1870, and
we were collecting 14 pieces of data about each
person. In 1790 we gathered one line of data per
household. Now we collected several lines per
person. Census-taking was a hundred times harder,
and the accuracy was slipping as well.
In 1879 Herman
Hollerith joined the Census Office. He was only
20, and the Office was a world of endless copying
and tallying. Imagine the problem. Someone asks,
"What percent of our population are Irish
immigrants?" How do you get an answer from millions
of data sheets? The idea of mechanical sorting was
only a dream. No one had a workable method.
One person had tried making ink marks on a
continuous roll of paper. Hollerith improved that
by punching holes in the paper, like a player-piano
roll. Those holes could be used to register each
piece of data mechanically, the way player-piano
notes are sounded. But those methods lost the
identity of individual records. They opened the
door to really nasty errors.
One day, Hollerith talked with John Billings, a
doctor in charge of health statistics. Billings
said, "There should be a way to use separate cards,
with notched edges, to keep track of data." Bingo!
Hollerith saw it. He developed a system for
punching all the data for each person into a single
card. If you were a citizen, and literate, one hole
went in column 7, row 9.
There was much more to it than that. Still, he had
a full system working in time for the 1890 census.
He invented efficient means for punching cards. He
showed how to read the cards electrically. By 1890
an operator could punch 500 cards a day. He could
tabulate, or read, 8000 cards a day. By 1900, he'd
added automatic tabulators.
If you took up the computer more than a decade ago,
then you've also worked with Hollerith cards. Not
long ago, you typed each Fortran command on its
own card. A machine
tabulated your cards and sent your program to the
You see, Herman Hollerith eventually left the
Census Office to form his own company. He called it
International Business Machines -- IBM. And that's
why the computer age rode in on those wonderful old
1890 Census cards.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds