Engines of Our Ingenuity

No. 684:
THOMAS MIDGLEY, JR.

by John H. Lienhard

Click here for audio of Episode 684.

Today, an inventor transforms us. He also threatens our lives. 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.

You may recognize two lines from a political poem by James Russell Lowell: "New occasions teach new duties, Time makes ancient good uncouth." So it is with some inventions. Meet Thomas Midgley. He gave us two ancient goods that've grown uncouth.

Born in 1889, Midgely did an engineering Ph.D. at Cornell. In 1916 he joined Charles Kettering's Lab in Dayton, Ohio.

Kettering was marketing a small kerosene engine to drive home-lighting systems on farms. It knocked horribly. Midgely guessed that dyeing the fuel red might cause it to absorb more heat and knock less. That was terrible physics. But when he doped the kerosene with iodine, there was less knock.

Midgely set out to find a better antiknock additive. First he wasted time with a hit-and-miss search. Then he began working systematically through the periodic table. After six years he found that tetraethyl lead worked beautifully.

So Ethyl gasoline swept America. Questions about its toxicity came up right away and lingered for sixty years. Finally, we introduced the new catalytic converters to combat other pollutants. They strangled on leaded gas, so we gave up lead. It certainly had been a health threat. But it also allowed the modern auto engine to evolve.

Midgely took only three days to make his second great contribution. Early refrigeration units used nasty chemicals like sulfur dioxide and ammonia. We needed something better. Midgely went back to the periodic table and invented dichloroflouromethane -- the first of the Freons.

The Freons aren't toxic at all. So they served us long and well. Then we found they were eating up our protective ozone layer. Now the survival of Earth depends on giving up Freons. We're replacing them with new chlorine-free chemicals.

So, Midgley changed American life twice. Both times his inventive heritage was life-threatening. And his final invention was really death-dealing, as it turns out.

He contracted polio when he was 51. As he lost the use of his legs, he invented a harness to get himself out of bed. On Nov. 2, 1944, he tangled in the gadget. It strangled him.

Midgely studied history, loved music, wrote poetry. His inventions shaped and changed us. Then we had to leave them behind. So we weigh his life. Kettering boasted that Midgley was his own greatest discovery. He might well have been.

Change is the only changeless thing in our lives. Midgley rode change. Now we forget leaded gas and Freon. But let's remember Midgely. Let's remember the processes that've made us.

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

(Theme music)


Kauffman, G.B., Midgley: Saint or Serpent? Chemtech, December 1989, pp. 717-725.

For the Russell poem, see, e.g., Hymn No. 519 (Ton-y-bot-tel) in the 1940 Episcopal Hymnal. Other churches have also used this hymn setting of the text. However, the text is now falling out of favor since it so patently reflects specific 19th-century politics.

For more on Midgely see the following website:

http://en.wikipedia.org/wiki/Thomas_Midgley

This episode is from 1992. In 2009, Steven Karty writes to suggest that I should've been less critical of Midgely's invention of Freon and leaded gasoline. Freon substitutes are less efficient his Freon, and might well be exacting comparable costs to the environment by requiring more energy to run cooling units. And one needs to look critically at the chemicals that have replaced lead to prevent engine knock.



The Engines of Our Ingenuity is Copyright © 1988-1997 by John H. Lienhard.

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