NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Calibrating a sextant scale
From: Mike L
Date: 2007 Nov 20, 03:33 -0800
From: Mike L
Date: 2007 Nov 20, 03:33 -0800
Whilst it is easy to calibrate a sextant's zero reading, is there any way to calibrate any other readings? My thought was to lean over a cliff and view my own reflection, and then align the mirror with the horizon, this should be somewhere close to 90deg (give or take the variation of the horizon from horizontal). Having established the true 90degree, the 45degrees could be calibrated by finding two objects precisely 90degrees and finding an object exactly halfway between. Then it occurred to me that I could use a bucket of water at the seaside, to give two readings (direct and false horizon) one being exactly** twice the other. (** allowing for known errors) at which I've just realised that star charts are far easier ..... but it might amuse others to think about leaning over a cliff! --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
