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: Agnostic gnomon and horary error
    From: Geoff Hitchcox
    Date: 2024 Jun 2, 06:49 -0700

    You can measure it in the photo. The style of the thing does not make it possible to re-tilt it in any efficient way, so there it is, wrong by 7° for over sixty years!

    I think I may have a solution to this Sundial issue Frank.

    Because Amazon allow you to download a "sample" of the Sundials Book (if you have a Kindle), I downloaded the FREE sample of the Sundial book to my Kindle. Using a school-boy protractor, I measure the angle of the Gnomon as being near 41 degrees, not the 48 degrees I measured on your Black and White image (or the photo on the Amazon WEB Page). I have attached my screenshot of the Kindle cover - I would be interested to see if you also get near 41 degrees Frank.

    My thoughts are that the Black & White image you have (and the Amazon Web page) is a quick and dirty photo someone took to just show what the book cover looks like - with an inherent 7 degree rotation. The Kindle cover is the 'better' true digital image of the cover of the book, that (on my phone screen) has about a 41 degree Gnomon.

    So I think the Treworgy Sundial is probably just fine, and I agree with Chuck_V that the "actual sundial" should be measured.

    So maybe it is not true - that the camera "never lies".

    Regards, Geoff Hitchcox, Christchurch, New Zealand.

    File:


       
    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