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SUNDIALS 1
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Sundial Photos (1)
Sundial Photos (2)

PHOTOGRAPHS AND LINKS

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Sundial Photographs:
B&Q Ornamental Sundial &
     Experimental Sundials
 More Sundial Photographs

Sundial Links:
British Sundial Society
www.sunclocks.com
How To Tell Time Without a Watch
Time Centre - When Time Began
Sundials on the Internet
Phil's Sundial Page
Sundial Page
Sun Survey Systems
Portable Sundials


Sundial
SUNDIALS


I have been fascinated with sundials since I was a child. I would often admire a dusty old sundial in the corner of some public garden or stately home. I did not investigate further until recently.

I was in the DIY centre, B&Q,  recently and saw a large and attractive ornamental garden sundial at a very good price, it was duly snapped it up.

Once back home I tried to calibrate it at midday and then subsequently tell the time. Unfortunately it did not seem to work.  I then realised when calibrating a sundial that midday is Local Midday at Sun Time not GMT midday. So when it is midday in Greenwhich it is about 12:05 in Norwich and about 11:45 in Bristol.

This was not the only problem, the pointer, properly called the  gnomon, was actually misplaced by the sundial's designers so it had no chance of telling the correct time. A little bit of re-engineering later and the dial was telling the correct local 'sun time', which was very rewarding.

Essentially the designer had a mis-understanding of the design of a sundial and had placed the base of the gnomon between the 9am and 3am markings, right in the centre of this particular dial. This meant that at 6pm the dial indicated that it was 3pm.

For the dial to function correctly it should have been placed between the 6am and 6pm markings. Once the gnomon had been unscrewed and removed from the face of the dial new holes were drilled in the dial face to re-fix the gnomon in the correct position. Once this was done, the dial performed more than  adequately.

So a handy hint is that when purchasing your sundial, ensure that the point at which the leading edge of the gnomon meets the face of the dial is on a line that joins the 6am and 6pm markings, this will give the dial a "fighting chance"!

There are other more scientific factors to be taken into consideration too, I shall not go into them in too much detail, but there are a few point which should be kept in mind. Take a look at page 2 to find out a little more.





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