990K views · 18K reactions | In 1813 a Shaker woman named Tabitha Babbitt in Harvard Massachusetts changed the world with an invention she did not keep for herself but instead gave to all. While watching men work with a two man pit saw that wasted energy on the return stroke, she used her spinning wheel and a notched tin disk to create a circular saw powered by continuous motion. Her simple observation sparked an idea that spread quickly and helped build a nation. | History Vault | Facebook