Forsell Air Reference turntable - a long, long length of dental floss driving from a remote motor. It was a friend's system and trying to get the best pair pump and best air reservoir, plus experimenting with different floss would have exhausted anyone's patience. And then there was the linear tracking arm with air bearing....
If you've never seen one, look at https://www.whatsbestforum.com/data/attachments/10/10567-cd62a15533b0947e5f62f4673862f156.jpg
If you've never seen one, look at https://www.whatsbestforum.com/data/attachments/10/10567-cd62a15533b0947e5f62f4673862f156.jpg