Add new comment

Permalink In reply to by Anonymous (not verified)

A compass tells you magnetic north, not true north. You'll have to add or subtract depending on your location from magnetic north (which wanders from year to year).

Here's a site to generate the needed dimensions and positions automatically so you can verify that you've got yours right:

http://analemmatic.sourceforge.net/cgi-bin/sundial.pl

It makes a PDF of plans specific for your latitude and longitude.

Filtered HTML

  • Web page addresses and email addresses turn into links automatically.
  • Allowed HTML tags: <a href hreflang> <em> <strong> <cite> <code> <ul type> <ol start type> <li> <dl> <dt> <dd>
  • Lines and paragraphs break automatically.
  • Want facts and want them fast? Our Maths in a minute series explores key mathematical concepts in just a few words.