Sun Compass

Discussion in 'The Training Wing' started by Gadgwah, Jun 28, 2012.

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  1. Anyone know where I can get the instruction on how to use a sun compass.

    Tried googling it but all I get is the surveyors solar compass.

    Any help gratefully accepted,

    Cheers
    Gadge
     
  2. Which Sun are you using? The old MkI sun, or the new MkII Sun?
     
  3. Grumblegrunt

    Grumblegrunt LE Book Reviewer

  4. _Chimurenga_

    _Chimurenga_ LE Gallery Guru

    I have a set of instructions for the Cole Sun Compass, it's from a small brochure entitled "Navigation in Deserts" by Captain D.N. Hall.
     
  5. Just to be awkward, a Mk III.

    Cheers
    Gadge
     
  6. No wonder you're having issues. The MkIII was invented for the Moon. You'll be 180 degrees out.
     
  7. Any chance of scanning and emailing it?

    Cheers
    Gadge
     
  8. _Chimurenga_

    _Chimurenga_ LE Gallery Guru

    PM sent.
     
  9. Given that there's a practical reason why you may want to use a sun compass rather than a magnetic one (magnetic anomalies or proximity to the poles etc), rather than following the directions given in Grumblegrunt's link ( Sun Compass|Viking Compass|Arctic Navigation ) to create a set of compasses that'll take you a year to do, blend ancient technology with modern.

    Suspend a plumb bob from a tripod. Place an analogue watch set at the correct geographic time (e.g. GMT rather than BST) on the shadow cast by the suspension point. Rotate the watch so that the hour hand points towards the plumb bob. Half way between the hour hand and the 12 o'clock is south if in the northern hemisphere, north if in the southern hemisphere.

    You can increase the accuracy by using a large piece of card marked with "hour lines" instead of the watch, just mark where the hour hand would be if it were a watch and follow the same procedure. The card could also be divided into degrees or mils as a protractor to show your intended travel bearing once you've determined where south is.

    What I've described is merely what every Boy Scout was taught in my younger days, determining the direction of south/north using a watch but has been adapted to use a shadow because in more equatorial latitudes the sun would appear to be directly overhead. The plumb line gives you a mark on the ground that is easier to work from.

    The Vikings had to adopt a more complicated system because they had no means of telling the time without first knowing direction; sun dials required the direction of south to be known. We have watches so we can cheat.


    E&OE
     
    • Like Like x 1
  10. Re my suggestion.

    If you're in the tropics at noon on a summer's day, put a brew on and wait an hour before you do this. It'll save frustration.
     
  11. The only reason for following this is just curiousity, I am aware of the using a watch to determine direction, but just fancied being able to use one of these.

    Thanks for all the help and comments, it truly is a fountain of knowledge here.

    Thanks
    Gadge
     
  12. I too have a sun compass. A Howard pattern one. After much research I concluded that it was useless without an up to date almanac with tables for the compass.

    Do let me know if I am wrong about this!
     
  13. _Chimurenga_

    _Chimurenga_ LE Gallery Guru

    Gadge,
    Posted to you in my lunch hour -

    "Navigation in Deserts" by Captain D.N. Hall

    "The Sun Compass" by The Compass Section, AFV School, Lulworth




    (check your PMs)