Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    Name or NavList Code:
    Email:
       
    Reply
    Re: More Regulus-Moon (Near) Lunar Fun
    From: Ken Muldrew
    Date: 2023 Apr 6, 19:31 -0600
    Map makers like David Thompson would always use calculated altitudes. They didn’t carry chronometers but did carry pocket watches, so they would take a time sight using a star (the sun if it was up) that was either rising in the East or setting in the West and then use that local time for their lunar calculation. As long as they weren’t moving East or West, and their watch could keep time for  a couple of hours, this worked well (there’s no difference in the number of sights one has to take, but it’s a lot more convenient when working alone).

    Ken Muldrew.

    On Apr 6, 2023, at 6:00 PM, Greg Herdt <NoReply_GregHerdt@fer3.com> wrote:

    This result lead me to wonder how navigators or map makers (thinking of Thomson or Powell here) would have taken these shots if they were by themselves and did not have assistants simultaneously shooting the altitude of the star/sun and the moon?


       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

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

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID 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