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.

There is also an online blog about engine turning and guilloché engraving machines, their restoration, and use. This site also includes a nice Engine Turning/Guilloché Guide & Glossary.

The Secrets of Horological Engine-Turning (Guilloché)

Joshua Shapiro, watchmaker and owner of J.N. Shapiro Watches, gave this presentation at the Horological Society of New York.

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.