View Single Post
  #13   Report Post  
Old 27-01-2006, 11:25 PM posted to uk.rec.gardening
Martin Brown
 
Posts: n/a
Default How to tell where you garden is facing? (South/North etc)

Kay wrote:

Stewart Robert Hinsley writes

OTOH, for gardening purposes, the direction of the sun at midday is
probably close enough - unless you're setting up a sundial.


If you're setting up a sundial, isn't enough to wait till the sun comes
out, and then align it so it shows the correct time?


Only on two days a year (ignoring daylight saving time). It is a mild
irony that UK sundials are normally calibrated for GMT and either read a
hour out or have additional systematic errors in midsummer when we have
sunshine and use the garden more.

Otherwise it could read up to 30 minutes out of sync with reality. You
need to know the correction for apparent solar noon for your longitude
and date. The seasonal analemma curve is very beautiful.

http://solar-center.stanford.edu/art/analemma.html

Well made sundials have a small table of corrections or a devisouly
shaped gnomon to allow for this.

Regards,
Martin Brown