How to drill holes in ancient pearls?

Ancient craftsmen first fixed pearls in a clamp, and then turned the fishing rod and pulled it back and forth with a kind of manpower widely used in tradition, which was not complicated.

This kind of human-driven drill pipe was the main drilling tool in carpenter's shop 30 years ago. Its principle is to tie a drill bit to one end of a straight wooden stick and wrap a thin layer of thong around the whole longitudinal direction of the stick. The thin thong is horizontally equipped with a cross bar, which is pulled back and forth, and the thong drives the vertical cross bar to rotate back and forth, so that the drill bit drills through the material. This is also applied in ancient jade processing.