America: Facts or Fiction - Season 13 Episode 21: Locomotives
Release date: July 30, 2007
Description:
"Modern Marvels celebrates the ingenuity, invention and imagination found in the world around us. From commonplace items like ink and coffee to architectural masterpieces and engineering disasters, the hit series goes beyond the basics to provide insight and history into things we wonder about and that impact our lives. This series tells fascinating stories of the doers, the dreamers and sometime-schemers that create everyday items, technological breakthroughs and manmade wonders. The hit series goes deep to explore the leading edge of human inspiration and ambition."
Highlights:
Hand saw has teeth pointing forward (to cut on the push stroke) with gullets (spaces between the teeth) which fill up with swarf (debris).
Kerf = cutting groove
Set = the alternative outward bend to the teeth
Start off sawing with a nick or groove made by pulling saw teeth backwards.
Prehistoric flint stone saws have been found.
4900 BC - Egyptians had metal or copper saws to cut soft woods; later they were made of bronze
700 BC - Teeth were set in direction of cut
1730's - Amputation saw (no cleaning which led to a lot of infection especially when the doctor just went from one patient to the next). They basically sawed back and forth on the bone.
1930s - Crosscut saws were invented
Timber cutting is one of the most lethal jobs in America - 110 deaths per 100,000 workers.
You may be able to find this video on the History Channel or on YouTube. I couldn't find it on Amazon.
Official Modern Marvels Site
Direct Link to Saws Episode
Picture Credit: https://woodandshop.com/woodworking-hand-tool-buying-guide-handsaws/
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