John Carmichael wrote:
<<I think Mike Shaw has a posting somewhere of horribly wrong sundials. Mike
are you there? >>
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Hi John and everyone.
Yes, I'm still alive and watching the list with interest.
You're right (as usual), but I think you are remembering a short
presentation that I did at a sundial society conference (NASS I think) some
time ago.
I give quite a lot of talks about sundials, and I often finish with a short
section illustrating "what to look for when buying an 'off-the-shelf'
sundial".
Bear in mind that these talks are for the uninitiated.
Things to look for are:
a) Is the gnomon perpendicular to the dial face and pointing in the right
direction?
b) Are both shadow casting edges straight?
c) Is the angle of the gnomon equal to your latitude?
d) Is there a noon gap?
e) Is the dial origin on a line joining the 6am to 6pm marks?
f) Do the numbers go round the right way for your location?
These points are illustrated, using one of Tony Moss' excellent horizontal
dials, on my web page (see below), which, I'm afraid, is sadly in need of
some maintenance - follow the link to "Buyer's Guide".
That all said, I do have a collection of photos of about 15 or so "horribly
wrong" dials which display all these errors which I will happily post,
off-list, to anyone interested.
I see that I have them in a folder entitled "Crap".
These were all on sale to the public in garden centres, ebay etc..
BTW, do we still need the maximum attachment size restriction on the list?
Mike Shaw
53'22"N 03'02"W
www.wiz.to/sundials
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