Welcome to the NavList Message Boards.


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

Compose Your Message

Add Images & Files
    Re: Breed's Graphical Navigation
    From: Sean C
    Date: 2015 Feb 28, 03:53 -0800


    I wish I could take credit for the idea to cut and fold the diagram, but that was Hanno's suggestion in post g30486. I must say, I am amazed by your analysis in post g30505. I was trying to wrap my head around just where the vertices of the pyramid would be located in relation to the Earth. You have confirmed my suspicion. You must be highly adept at thinking in 3D, not having the actual pyramid in hand.

    ...Which leads me to:



    Having constructed the pyramid as described, I instantly understood what Antoine was explaining. I sat staring at it, trying to visualize the Earth in relation to it. As Antoine explained, if the line CP represents the radius of Earth, it becomes immediately obvious that the points O and S cannot be on the Earth's surface. What I am still confused about is how angle OC'S' is equal to the zenith distance of the body. But I suppose reading the book and a little more staring might help with that. ;)


    Sean C.


    I believe Antoine mentioned "Brent's pyramid" several times. No doubt he was referring to "Breed's pyramid". Perhaps that contributed to some confusion? (Just blame auto-correct, Antoine. ;) )

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    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 Settings

    Posting Code:

    Custom Index

    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