NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Drum Sextants VERNIER READINGS
From: Joel Jacobs
Date: 2005 Jun 16, 12:09 +0000
From: Joel Jacobs
Date: 2005 Jun 16, 12:09 +0000
Frank,
Thank you for saying that.
Some people think they are getting short changed when there is only the index and no hash marks. It should make no difference since you can visually estimate with great accuracy the intermediate reading. Power Squadron members sometimes confuse the USPS degree of sight reduction accuracy required with Ho.
Where there are intermediate marks on a sextant's vernier they usually are:
5 = 12 seconds arc
6 = 10 seconds arc
10= 6 seconds arc ( Navy MK III)
Joel Jacobs
--
Visit our website
http://www.landandseacollection.com
Visit our website
http://www.landandseacollection.com
-------------- Original message from Frank Reed <FrankReedCT@AOL.COM>: --------------
> I've also noticed that some Plath sextants don't include a little vernier
> scale for reading off tenths of minutes. But in practice, I find that this
> matters relatively little. I can read to 0.2 minutes (which is as good as it
> gets, in my practical experience) with or without the vernier scale.
>
> -FER
> 42.0N 87.7W, or 41.4N 72.1W.
> www.HistoricalAtlas.com/lunars
