There are mechanisms in nature as well as in human endeavors like engineering and art. Since 1988, the creative manipulation of these mechanisms has been explored in short radio essays about the history of technology called "The Engines of Our Ingenuity."

The man behind the series is retired University of Houston engineering professor, John Lienhard, who broadcasts his essays Monday through Friday from the university's public radio station, KUHF. Through the Internet, he now has fans all over the world.

"The University of Houston College of Engineering presents this series about the machines that make our civilization run and the people whose ingenuity created them," said Lienhard.

John Lienhard captures the imagination of listeners every week with stories about such technological achievements as China's Great Wall.

"It probably did serve the purpose of keeping invaders out, but it was finished just as the new cannons were being perfected; artillery was about to put an end to all great walls," he reads into a microphone.

His fans marvel at his ability to explore technology and other subjects in ways that are often unexpected.

"People want to be surprised," he said. "If the story is expected, it will be dull, ipso facto [by its very nature]."

Lienhard achieves surprise by looking into old books and engineering manuals for information about technology that changed the world.

"The trick is to jump from one thread of context to another thread of context and show that this thing links to this thing in an unexpected way," said Lienhard.

"The Engines of Our Ingenuity" is broadcast Monday through Friday and it is gaining a worldwide audience online. Lienhard says he hopes the program has helped make science and engineering accessible to more people.

"The Internet has changed that radically, because now everybody can know something about science, everybody can know something about technology," he said.

At 81, Lienhard now relies on other contributors to write some of the essays, but he says he still enjoys telling stories that both entertain and educate.

"Learning is like invention in that way," said Lienhard. "If we can bring people to the fun of it, to the pleasure of mental exercise and mental accomplishment, if we can do that, then the game is ours."

Many of the essays are available in Spanish online at kuhf.org.

There have been 2,750 three-and-a-half-minute episodes of "Engines of Our Ingenuity," with many more to come.