Today, a grimy man helps us think more clearly. 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.

My son is home for a visit. He's driving the old 1978 Nova he inherited from his grandmother. It runs like a top, but it looks its age. He needs to replace body parts. We go off to the junkyard together.

"Do you have Nova parts." "Yeah, take your tool kit to row 26." We enter the old graveyard. Row on row of wrecked cars are piled in towers, three cars high. We find a Nova on top of one pile. My son clambers up the stack with a screw driver. He pries loose an arm rest and a window gutter.

I wait in wreckage that reaches as far as my eye can see. Engines, tires and hubcaps have all been stripped. You buy them in the building. Doors, hoods and bumpers are missing randomly. Nearby, a grimy man breaks the deep silence with his scavenging.

Out in front are an old 1935 tractor and a 1970 pink Cadillac. They're both in perfect repair. I ask about them. Vintage tractors are one man's hobby. Another made his own pink Cadillac out of junk -- just for the fun of it.

I climb on the tractor. It's a lovely piece of history. The parts are clean and understandable. You can see how the carburetor, clutch, and crank starter all work. You learn from this old machine.

The cars in the lot are newer. They're more complicated. This is no place for stupid people -- for uneducated academics like my son and me. If we're to use this place we must be smart like the grimy men around us. We must know how things work. We must be able to figure out what we don't understand.

A man needs to use the bathroom. The men's room is occupied. He uses the ladies' room. No matter -- there isn't a woman within a mile. Our world makes places like this invisible to women.

We teach each other many wrong things. We've been taught that this male preserve is ugly. So I gaze at twisted metal and cannibalized husks of once shiny automobiles while my son pays. He has $300 worth of parts. They cost him $16.

This place speaks of death and regeneration. It speaks of conservation and reuse. The wild tangle holds order and beauty. It's like humus on the floor of a virgin forest.

The man nearby moves quietly. He knows things most of us do not. He knows how machines work. He honors regeneration. He sees the beauty of function. He can create in his mind and execute in the world. I can learn from these grimy men. They accept me for now -- not as an equal, for I am not. But they know that I honor this place. And that is enough.

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

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