Today, we meet the man Ben Franklin called an honest heretic. 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.

The Reverend Joseph Priestley fled from England to America in 1794. The greatest intensity of our American Revolution, and of the English Industrial Revolution, were past. Priestley had played a large role in that great overturning of the English-speaking world. Those twin revolutions had been opposite faces of the same coin, and he bore deep scars from the political wounds he'd suffered as a warrior in the Industrial Revolution.

Priestley was born in 1733 and raised as a Protestant, outside the Church of England, in rural England. He was ordained as a minister when he was 22. For the rest of his life he served as a preacher, a scientist, an educator, and -- always -- a revolutionary. He advocated laissez faire; education to prepare students for daily life; and democracy as a way to achieve "the greatest happiness for the greatest number." He believed that Christianity spoke to material human need. He was branded as an Antichrist and a heretic; but his beliefs were nearest those of early Unitarians.

He met Ben Franklin in England, and Franklin encouraged him to finish a book on electricity. By the time he was 33, that book had led to membership in the Royal Society. The next year he took a parish near Leeds, and he also started studying mercuric oxide. He found that heating it released the gas that would later be called oxygen. He thought it was exceptionally pure and breathable air -- the Aristotelian principle of air. He also found that after air was killed by burning a candle in it, growing plants would restore it. Priestley put others on the road to identifying oxygen in modern terms -- as a chemical element.

In 1780 he took the parish of a dissident Protestant group in Birmingham. There he joined a small cell group made up of the major industrialists and intellectuals of the day -- men like Boulton, Watt, Wedgwood, Erasmus Darwin, and the astronomer Herschel. These fomenters of the Industrial Revolution studied science, technology, and philosophy. And they bred change.

But after 11 good years there, on Bastille Day, conservative rioters destroyed Priestley's church, his home, and his laboratory. The mob wanted to lynch him and his family, too, but they slipped away with minutes to spare. He lay low for a while and then moved to Lancashire, Pennsylvania. He died there in 1804.

Ben Franklin wrote one of Priestley's students in 1788 and sent greetings to this kindred spirit: "Remember me affectionately to the honest heretic, Dr. Priestley ... " he said.

I wish I could show you Priestley's American portrait over the air. It's a good face, an open face, an intelligent, courageous, and secure face. He looks so much like Jefferson.

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

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(Image courtesy of the Burndy Library, Dibner Institute for the History of Science and Technology)
Joseph Priestley