Len polishing machine. Drawing of a lens polishing machine made in 1683 by the Dutch physicist and astronomer Christian Huygens (1629-95). It was a crude, vertical lathe, worked by hand. The lens blank was sandwiched between the square table and the grinding tool (the rod above the table). The grinding tool was made of wood, metal or cork. The motion of the lathe was achieved by moving the bow (marked 'N' to 'O') backwards and forwards. The final polishing of the lens was done by hand with paper in Huygens' workshop. Huygens performed reflection and refraction experiments with light. He proposed a theory that light was comprised of waves in his 1690 book Traite de la lumiere.