Hello Fearn, I'm talking about making a concentric circle not drilling a hole. The center hole comes first, then the circle. One way it is done is the way described above and another way is the use of a spool on a shaft with a sharp cutting bit inserted in the spool. Both ways use a center shaft with a point and can be rotated by hand or the use of a bow. Here is a link that might interest you
http://www.jstor.org/pss/282168 I just wish that there were pictures to show what I am having a problem describing.
Robert