NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Martin Whittle
Date: 2022 Dec 22, 14:37 +0000
The correct readings for your two pictures are 14d 2.0m and 17d 0.6m. You use the indicator next to the main limb to read the degrees. They read approximately 14 and 17 respectively though they are unfortunately slightly less than that.
The vernier scale next to the drum has six lines, the upper one is longer and is the pointer to the drum scale and gives the minutes. Both show the minutes scale readings is just over 0 despite the main indicator seemingly less than 14 & 17.
Ignore that discrepancy. Some sextants allow one to free the drum from its shaft and you should adjust the drum position so that the drum indicates zero when the main limb indicator is on a whole degree. I believe your sextant does not allow such adjustment.
Back to the vernier scale. The long line is the pointer for minutes. Alignment of the vernier scale marks represents .0, .2, .4, .6, .8 and lastly again .0 minutes. Do not add a whole minute if the last mark is in alignment. The first and last will be aligned simultaneously. Further iff or example if .2 and .4 are equally aligned then it should be read as .5.
DaveF
