Jim,
Thanks for bringing up this subject. It's always fascinated me since I started working in machine shops in my teens.

The vintage machinist nuts, like the vintage gun nuts, are out there.
http://www.practicalmachinist.com/vb/ant...obinson-112172/

Most of the 19th century indicators I've seen were simple lever types with ratio multiplying (the pointer end longer than the contact tip). I suspect that design has roots as far back as the need for test indicators goes.

Last edited by Chuck H; 02/06/11 11:44 AM.