Today, we invent liquid paper, brown bags, and brassieres. 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.

Here's a book called Mothers of Invention by Vare and Ptacek about women inventors. The creative array in the book is vast. Of course, the inventions lean toward home and hearth -- the child's toilet seat, brown paper bags, the brassiere, and vacuum canning. The foreword is by actress Julie Newmar, who played Catwoman in the old Batman TV series. That's because she's one of the inventors in the book. She holds a patent for a clever panty hose improvement.

Typical of these inventors is Betsy Nesmith, who gave us Liquid Paper. She was a secretary using the new IBM typewriter in 1951. Its ink left nasty smudges when you erased it. So in a burst of creative frustration, she went home and invented a liquid for painting out mistakes. It's base was white tempera paint.

The liquid was an immediate hit with other typists. By 1956 she had a cottage industry going. She labeled it "Mistake Out," and her small son Michael helped her fill hundreds of bottles a month. When that number reached thousands, she renamed it "Liquid Paper." Then one day her mind wandered, and she typed "The Liquid Paper Company" on a letter instead of her employer's name. She was fired, but no matter: her Liquid Paper Company was putting out 25 million bottles a year when she retired as chairman of the board in 1975. Betsy Nesmith died in 1980 and left a fortune to be divided between her son and the large charitable foundation she'd set up.

A common thread among these women is problem-solving. Melitta Bentz invented the so-called Mellitta drip coffee-making process in 1909. She was really just trying to keep the grounds out of her own coffee. Sara Baker became an M.D. in 1898 and went into public health. She patented everything from children's clothes to special eyedrops for preventing the congenital blindness caused by gonorrhea. She turned her creative energies loose on the problems she fought daily in the Hell's Kitchen ghetto area of New York. It was her detective work that tracked down the notorious Typhoid Mary -- the unwitting carrier who transmitted typhoid all over New York.

Oddest of all these inventors was Hedy Lamar. During WW-II, she played roles like the exotic Tondelayo in White Cargo. But she was also co-inventor of a submarine communications system. Her system switched among radio frequencies to defeat enemy monitoring. Hedy Lamar never let interviewers get near the subject. Authors Vare and Ptacek think she saw inventive ability tarnishing her carefully-tended sex-symbol image.

That, of course, has been the great contaminant of women's inventive genius. Still, it's clear as day that hard-core mechanical creativity is every bit as strong in women as it is in men.

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

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Vare, E.A. and Ptacek, G., Mothers of Invention. New York: Quill, 1987.