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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Timing Lunars with a Rock
From: Bruce Stark
Date: 2005 Jul 18, 13:01 EDT
From: Bruce Stark
Date: 2005 Jul 18, 13:01 EDT
The old navigation manuals suggested checking the log line and half minute glass occasionally. One way to check the glass was by pendulum. As I recall, the length of the pendulum, to the center of the musket ball that formed the weight, was sometimes given as 29 and 1/4 inches, and sometimes as 29 and 1/8. Count a second each time the pendulum passed the bottom. I suppose you had to give the pendulum a few moments to settle the length of its swing.
Bruce
Bruce