photo #6092008

Before we found a way to safely perform C-sections in the mid-1960s, a brutal surgery known as a symphysiotomy was used to widen a laboring mother's birth canal — by use of scissors or a serrated knife. Besides being excruciatingly painful, this procedure was slow and precarious work. So in 1780, two Scottish doctors named John Aitken and James Jeffray devised a tool with a rotating blade that could more efficiently cut through bone and cartilage. Able to fit in the palm of a doctor's hand, the blade rotated by hand-crank — and is now considered the prototype for the first chainsaws.