Today, a look back. 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.

Sometimes I find myself grasping to remember the sights, smells, and texture of life before WW-II. I have little sense of having undergone much change, yet I know it'd be a terrible wash of cold water if I were suddenly plopped back into that world.

Let's compress the scale of that idea a bit. In 1982 you either typed letters and reports on a typewriter or, if you were one of the more fortunate, handed them to a secretary. Think of the magnitude of your dismay if you had to go back to that world. Or remember the '50s, when you had to make copies with carbon paper.

We've all been through the process of deciding that it wouldn't be so nice after all to find ourselves back in the Golden age of Athens or the Italian renaissance. But the fact is it wouldn't be so nice to find ourselves back in the roaring '20s or even the excitement of the mid-sixties.

The greatest advances have been in public health. The length and quality of human life are far greater today, even in poor countries. One sensate recollection of the 1930s that I can build with great clarity is a visit to the dentist's office. I was cavity-prone, yet I experienced no pain-killer until after WW-II. Dentistry was simple torture, and I still cringe when I think of it.

But most of our remote childhood takes on the soft edges of reverie. That makes it hard to see the extent to which technology is a force improving the quality of life. Let's make a quick inventory of some true tastes and smells of life in the '30s.

Alcoholism was rampant. All we had to do was to look down our street to find friends whose lives had been devastated by the stuff. We didn't understand its effects. Alcohol was regarded as a universal medicine and a calming agent. A child might be given heated Scotch and honey as a cough remedy.

Doctors made house calls, but they couldn't fix anything. No antibiotics! Vitamins hadn't yet reached the public consciousness. Tuberculosis was largely incurable. Infectious diseases like measles and chicken pox had to run their course while your house was quarantined with a yellow sign warning visitors not to enter.

Tires didn't last 10,000 miles. No interstate highways. Any long trip meant a breakdown or two. And only the well-to-do took automobile trips. Nobody traveled in airplanes. Going overseas meant an ocean voyage.

When beggars came to your door, you were expected to put them to work chopping wood or raking leaves and to give them a sandwich. For hunger was abroad in the land. It was a real sign of status for a high-school student to get a job sacking groceries. College was only a rumored place for most people.

I still look back at toboggans, streetcars, and radio tubes with enormous nostalgia. For those things formed me. But then I look around at the world I live in now, and I can only say: Thank God for the machines that make our civilization run!

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.