Engine turning is about inscribing geometric patterns onto an object -- typically something metal. This is work done on a rose engine lathe, and is often done on high end watches.
For more information, see the article about Guilloché.
The Secrets of Horological Engine-Turning (Guilloché)
These two videos are from Casey Burns (CBWIM onYouTube). He uses a home-built engine turning attachment that he says can be used on any lathe, wood or metal, provided it has a faceplate. He use this for engraving the metal disks that he inlays into the end caps of wooden flutes.