Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
    Re: Read the vernier, get the noon latitude
    From: Brad Morris
    Date: 2018 Feb 10, 13:24 -0500
    Hi Bill 

    Begin read a vernier by deciding the base value.  We decide that by finding the nonius.  The nonius can be found on the scale numbered 0 through 20, known as the vernier.  The nonius is the line marked zero.  We see that it is between 73°40' and 74°00' on the arc of the sextant.  Hence the base value is 73°40'. 

    The vernier is marked from 0 to 20, these correspond to minutes of arc.

    Next, we must find the added value.  We  decide that by finding the two lines which best align between the arc and the vernier.  Look across the lines and you will see that the alignment best occurs at either the 13th or 14th division of the vernier, depending upon your persuasion. Count them for yourself.  The 13th line corresponds to 13 arc minutes whilst the 14th line of the vernier corresponds to 14 arc minutes.  The added value therefore is 13 or 14.

    Thus we have
    73°40'
    00°14'  additive
    73°54'  

    I hope that helps

    Brad




    On Feb 10, 2018 2:39 AM, "William A" <NoReply_WilliamA@fer3.com> wrote:

    Gary. thank you. I can see the 40 minutes part better! I thought I understood the vernier part. Now it doesn't make sense.


    I look at the vernier and they line up at 83 degrees. what happens next? do you add that on 40? Thank you, sir. Bill


    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site