Ken,
You wrote:
I take it the motor is to keep the hole pointed toward the sun.
It’s to keep the cylinder pointed in the direction that the sun would be if it
kept standard time.
I should have added that this device includes the longitude correction as well.
I'm unclear though on what's drawn
Hi,
You can also see a magnificent heliochronometre made by John Carmichael
at:
http://www.flickr.com/photos/jlcarmichael/3576166915/in/set-72157618973847752/
best wishes,
Peter
On 4/02/2013 3:13 PM, Ken Baldwin wrote:
Thanks, everyone.
I see now how an analemmic gnomon can be used
Ken,
I’ve found a couple of small photos of my rather crude device.
I’ve posted then in Dropbox at :
https://www.dropbox.com/sh/tkxqw7x5mbr1axd/tYOlNAwT60
By coincidence, the 2nd photo shows the EoT is –7.5 minutes and sun’s
declination is –7.5 degrees.
I hope that makes things clearer.
Of
, Netherlands
lat. 51:30 N long. 5:30 E
- Original Message -
From: jmikes...@ntlworld.com
To: Ken Baldwin ; sundial@uni-koeln.de
Sent: Monday, February 04, 2013 9:59 AM
Subject: Re: equation of time sundial
Ken,
I’ve found a couple of small photos of my rather crude device
A good question, however except for the solstices, there is ambiguity. Each
declination has two dates. For example March and September equinoxes are 6
months apart, but same declination.
Simon
Simon Wheaton-Smith
www.illustratingshadows.com
Phoenix, Arizona, W112.1 N33.5
--- On Sun, 2/3/13,
Hi Ken,
One of the most beautiful (IMHO) is the Schmoyer dial which
incorporates the EOT in the gnomon. You can see a picture of the dial at:
http://www.precisionsundials.com/schmoyer.htm
best wishes,
Peter
On 4/02/2013 6:32 AM, Ken Baldwin wrote:
Hello,
I'm a new list member, and have
Hi Ken,
Here's another example of a dial which may interest you. This is my
adaptation of a brilliant dial coded by Steve Lelievre. To fit the size
limit on this list, I've had to squeeze the image greatly, but you
should be able to grasp the principle of the dial: each month is a
Hi guys,
Thanks for your responses.
I'm not trying to read the EOT-adjusted time from the device, I want to
read the actual EOT value itself for that date. For example, on Aug 9th, at
any daylight hour, I'd like to be able to read, say, -5.5 min. Maybe I'm
misunderstanding, but do I get that
Ken,
I think I made a device some time ago to do what you want .
A cylinder was tilted to the appropriate latitude angle and direction.
There was a small hole on one side of the cylinder which gave a projected a
spot of light from the sun on the inner opposite surface where there was a
graph
Subject: Re: equation of time sundial
Hi guys,
Thanks for your responses.
I'm not trying to read the EOT-adjusted time from the device, I want to read
the actual EOT value itself for that date. For example, on Aug 9th, at any
daylight hour, I'd like to be able to read, say, -5.5 min. Maybe
Hello All,
I think Mike nailed it, as to what Ken is asking. I know of no sundial,
other than Mike's here, that directly measures the Eot, rather than somehow
incorporate the EoT calculated elsewhere. I did not think this was
possible until I saw Mike's solution just now, because a sundial has
Thanks, everyone.
I see now how an analemmic gnomon can be used to read the EOT, if the
equatorial band shows both mean and apparent time and you do the
subtraction in your head. I'm most interested, though, in something which
allows a direct reading of EOT...
Mike, your solution sounds very
Hi Ken,
I think it would be straightforward to modify a heliochronometre to
achieve the same result as Mike's solution. In addition to the usual
figure-of-eight analemma, you'd add a centre line for local solar time.
After adjusting the dial for local solar time and 'zeroing' the (new)
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