NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Greg Rudzinski
Date: 2015 May 5, 07:24 -0700
Sam,
Aircraft clocks are not chronometers yet very well made and accurate. The pair that you have can be ajusted where you see the F S (fast/slow) on the back of the movement. With some patience these clocks can be adjusted to rates of less than +/- 10 seconds per day when kept at constant temperature and orientation. John S. Letcher discusses the 8 day aircraft clock as a substitute for a marine chronometer in his book Self Contained Celestial Navigation.
http://www.amazon.com/Self-contained-Celestial-Navigation-HO-208/dp/0877420823
Greg Rudzinski
From: Samuel L
Date: 2015 May 5, 03:32 -0700Greg,
During WW II my father got 2 cockpit clocks from downed German Messershmitts. Would these be an 8-day clock or at most chronometers? The run fine but I've never attempted to "rate" them myself.
You can see a picture of the clock at the top of the page in link listed below;
http://www.cockpitclock.com/JUNGHANS.html
Sam
