A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Michael Cain
Date: 2021 Sep 19, 12:06 -0700
I'll stand to be corrected by Dr. Morris, but, strictly/traditionally speaking, a chronometer is timepiece equipped with a helical hairspring, detent escapement and a fusee drive; if any of these features are missing, the timepiece in question is not a chronometer (this why the Hamilton Model 22s were referred to by the company and the USN as 'chronometer watches.') The Swiss are more generic in their thinking and apply the term to any timepiece meeting their standard of accuracy.