Hi Kevin,
The cam demonstration is great! And so are the other links and
animations. Thanks for alerting us to you webpage.
best wishes,
Peter
On 22/06/2011 19:58, Kevin Karney wrote:
Chi Lian
It's good to see someone thinking about the EoT !
And to other contributors, many thanks for your additions concerning
watches and clocks, which I was most interested to see
If you visit
www.PreciseDirections.co.uk <http://www.PreciseDirections.co.uk/>
Click on the Sundials link and then click the last item on the list
there "Representing the EoT", you will find a number of curves
representing EoT, including both the kidney polar curve and it's
'intrinsic' counterpart. The later - with equal spacing between points
is marginally easier to read, but is no use for mechanical devices.
The problem with the kidney curve - mechanically sound though it is - is
that it is just plain UGLY. Also it fails my test, which is "does it
teach anything about the sun, astronomy and sundials?" The answer, I
think, is "Not much".
So I prefer mechanical representations of the EoT which generate the two
components (obliquity and eccentricity) visibly and separately and then
recombine them. (The second and fifth item on my sundials web page,
mentioned above, are movies showing these in operation)
However, the master of all mechanical EoT generators must be the device
in the Strassburg cathedral clock. I cannot find a web picture of this,
but I have posted a not-very-clear photo of it at the above web-site
Best regards
Kevin Karney
Freedom Cottage, Llandogo, Monmouth NP25 4TP, Wales, UK
51° 44' N 2° 41' W Zone 0
+ 44 1594 530 595
On 21 Jun 2011, at 17:11, Chiu 邱,Chi lian wrote:
Hi,
I figured out a way to plot EoT curve which I didn't see in sundial
books I own.
Diagram is enclosed here.
For a better resolution one, see
http://dl.dropbox.com/u/31382133/EoT%20.png
Best regards,
ChiLian 24.8N 121E
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