Today, we suffer the loss of fire. 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.

"I shiver at the taste of fire ..." writes poet Carol Drake. Take a close look at Australia's prehistory, and you might well shiver. For fire tells that land's story.

Great destructive brush fires have swept Australia several times during the 20th century. In 1983 one killed 71 people and a third of a million head of livestock.

Ecologists have taken stock of this destruction. They've found, as we so often do, that it's the complex fruit of human intervention. That story begins 40,000 years ago.

The Bushmen -- thinly distributed over Australia -- lived in a dry land of highly flammable brush. Fire became their constant companion. They all tended fire -- carried it about with them. They used it freely. They hunted by lighting huge horseshoe-shaped brush fires. Fire herded wild animals onto their weapons.

That was only one part of it. They cut highways in the impenetrable forests by burning off the scrub. They lit fires to get better access to edible roots. Burn, burn, burn! Fire was their way of life.

Fire both suited and shaped the ecology. The eucalyptus and gum trees have tough leaves and powerful root systems. They hoard water. They're not easily harmed by fire. If fire does hurt them, they quickly send up new shoots.

By the time the English dumped prisoners in Botany Bay in 1788, an ancient balance had been struck among Aborigines, fire, and the land. Then white settlement began. Settlers drove Bushmen, and their ever-present firesticks, out. Underbrush accumulated. It took over a century to create a real tinderbox.

Those settlers should have listened to the old myths. Listen as they tell the story of creation:

In the early Dreamtime, the creatures of the world did not look as they do today. ... The Father examined them and said, "You are not a proper people and not proper animals. We must change this." With his firestick he lit a ceremonial fire that spread until it encompassed the world. It swept over all creatures. It burned the earth and the stones. After the fire had passed, the creatures and the humans took their present form and character.

The Bushmen knew perfectly well they were wed to fire. They knew that fire shaped them, and it shaped the world around them.

So the big destructive brushfires finally began in regions that hadn't been cleansed by fire for over a century. And we gaze at Aborigine art -- wild pointillist abstracts with titles like, "Fire Dreaming at Ngarna," and "Bushfire Dreaming."

As we look, we do indeed shiver at the taste of fire -- no longer there to daily cleanse and renew that vast land.

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

(Theme music)

Pyne, S.J., Fire Down Under. The Sciences, March/April, 1991, pp. 39-45.

The line of poetry is from one of the unpublished works of the poet Carol Christopher Drake.