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: Mylar Film as Artificial Horizon Windows
    From: Richard M Pisko
    Date: 2011 Mar 16, 12:35 -0700

    The mylar (as I understand the construction) is not supposed to be  
    stretched tightly on the frame.  How well does a flapping pane prevent  
    waves on the water surface?  Mind you, our winds today are about 50 kph  
    and a non cast iron frame might take off to the east; but I was really  
    asking about moderate breezes.  I should set up a tripod, theodolite with  
    solar filters, pan and frame . . . but it's just above freezing and I'm  
    cherishing my comfort more and more these days.
    Thank you,
    Richard . . .
    On Tue, 15 Mar 2011 17:39:42 -0700, Robin Stuart  
    > The fogging that I mentioned in the post also happens with the plastic  
    > and glass windows supplied with the Davis artificial horizon but at a  
    > slower rate. I don’t it think would be advisable to apply anything  
    > (onion juice, saliva etc.) to the windows as this might affect its  
    > optical properties and hence the sextant altitude readings. It is  
    > probably better just to let the water equalize in temperature with the  
    > air before putting on the windows. (Of course this only works if the  
    > temperature is above freezing which it often wasn't around the time the  
    > observations were made). Alternatively one might substitute sump oil or  
    > mercury for the reflecting surface in which case fogging should not be a  
    > problem.
    Richard . . .
    Using Opera since the"Dog" died

    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