tony cooper wrote:
snip
Well, Sarah Babbit - a Shaker in Massachusetts - notched a tin disk in
1810, attached it to the spindle of her spinning wheel, and cut
shingles with it. If Sarah hadn't come up with that, would Michel
have thought to replace the spinning wheel with an electric motor to
make it portable? Many inventions are simply progressions from some
previous form of the device. There are other references to circular
saw blades going back to the 1700s, so Sarah may have added to the
progression by attaching hers to a spinning wheel.


That's the story I've always heard. People have the idea that the
Shakers were/are Luddites, but nothing could be further from the truth.
For example, one of the main sources of income for the Shakers was the
washing machines that they basically invented and then built and sold to
hotels at a considerable profit.
Incidentally, Sarah Babbit was not the only woman who made a huge
contribution to "cutting edge" technology (couldn't resist that terrible
pun)--a French woman, whose name I don't remember, invented the welding
process that made the bandsaw possible. And, on the subject of hand-held
circular saws, the Craftsman that I own is direct drive, no gears involved.
Allen