As a young girl, Margaret "Mattie" Knight never played with dolls, preferring to make toys for her brothers instead. In 1849, Knight went to work in a cotton factory where she witnessed a "shuttle," a device that carries thread back and forth across a textile loom , fly off the machine when the thread broke, striking and killing a young boy about her own age. The 12-year-old Knight developed a safety mechanism that made it impossible for a shuttle to leave the loom. The design was so effective, soon virtually every new power loom carried her invention, saving countless workers from injury or death. Being so young, she didn't bother to patent the device, so she never received payment. Knight wouldn't make the same mistake later in life when she invented a machine that could produce flat-bottomed paper bags. Knight had built a small wooden model in her home, but she needed a metal version to show it could hold up to the stress of mass production. So she hired Charles Annan to make the full-sized machine for her, only to have him try to claim the patent for himself. When Knight sued , Annan's argument was that the design had to be his, because no woman could possibly understand the complex mechanics. Knight proved him wrong when she brought back her wooden prototype and explained how every part worked. She won the case in 1871, making her the second woman to hold an American patent. Over a hundred years later, her design is still used as the basis for many modern flat-bottom bag machines. But that wasn't the last the world heard of Mattie Knight. During her lifetime, she made about 90 inventions and received 26 patents, becoming one of the most productive female inventors of the 19th century. What do we know about Knight's first invention?
It is still used today. It brought her great profit. It was made when he was 20. It reduced injuries at textile plants.