Patsy Sherman's role in the invention of Scotchgard™ was a "happy
mistake". As a research chemist with 3M in 1953, a lab mishap with
fluorochemicals lead her to a new discovery. An assistant
accidentally dropped a bottle of synthetic latex that Sherman had
made, it splashed onto the assistant's white canvas tennis shoes.
The substance did not change the look of the shoes it couldn't be
washed away by any solvents, and it repelled water, oil and other
liquids.
In 1813, Tabitha Babbitt created the circular saw. It was circular
so that the teeth would continue cutting, unlike the straight saws
that only cut on the pull and not the push motion. Her other
building innovations, like machine-cut nails instead of individually
hand-crafted nails. As a Massachusetts Shaker community member, she
helped create tool innovations for furniture making. She lived a
simple Shaker life and never applied for patents.
The inventor of "Liquid Paper" or "White-Out" was Betty Nesmith
Graham. Graham got an idea she had seen done by sign painters, which
was to add another layer of paint to cover-up mistakes. She used a
kitchen blender to mix-up her first batch of substance to cover-up
over mistakes made on paper at work. After much experimenting and
then being fired for spending so much time distributing her product
as a trial, she received a patent in 1958.