Bow drill
The
bow drill has been used used by ancient
Sumerians and other groups to
drill holes in a piece of
wood, the
drill stick, into another piece of wood, the
hearth, with the help of a
bow. The heat thusly produced by
friction would set nearby
dust and tinder aflame.
Bow drills can also be used with a drill bit to bore a hole in wood for woodworking purposes.