Re: Construction-Principle of Capuchin & Universal Capuchin Dials

2017-05-10 Thread Michael Ossipoff 
Yvon--

Thanks for providing that information and links. If the links' explanation
seemed satisfactory to one dialist, then I expect that it *is*
satisfactory--and a satisfactory explanation is what I'm looking for.

I'll check out those two links.

Yes, it isn't an easy question, but even a difficult explanation can give
me a good hint, regarding the nature of where the construction came from.

So thanks again for the help, the information, the links!

Michael Ossipoff





On Wed, May 10, 2017 at 4:56 PM, Yvon Massé  wrote:

> Michael,
>
> Some years ago, I spent a lot of time to search a simple geometrical
> justification of these kind of dial. The best way I found is:
> - for the Capuchin: from the orthographic projection of the celestial
> sphere on the local meridian (fig. 1)
> - for the Universal Capuchin: from the orthographic projection on the hour
> plane of the Sun (fig. 4)
>
> These figures are detailed here:
> http://cadrans-solaires.scg.ulaval.ca/v08-08-04/pdf/XIII-4-p10-4.pdf
>
> and the links between the figures and the dial are briefly explained here:
> http://gnomonique.fr/divers/anal_3_angc.pdf
>
> Of course, it isn't quite simple but, perhaps, you will find some interest
> in these articles.
>
> Best regards
>
> Yvon
>
>
> Le 09/05/2017 20:50, sundial-requ...@uni-koeln.de a écrit :
>
>>
>> I'm not asking about the *instructions *for constructing Capuchin and
>> Universal Capuchin dials. I'm asking about the principle, the explanation,
>> the justification, for their construction.
>>
>> Some websites have said or implied that it has to do with an orthographic
>> planisphere. I'm familiar with the use of a universal planisphere, an
>> azimuthal projection of the celestial sphere in equatorial-aspect.  ...but
>> it isn't entirely clear how that relates to the Capuchin dials.
>>
>> I found a handwaving explanation on the web. I've pasted its diagram, and
>> some of its "explanation", below in this e-mail.
>>
>> The explanation says that the diagram below, an orthographic projection of
>> the celestial-sphere, looks just like a Capuchin dial.  And that's
>> supposed
>> to be an explanation.
>>
>> So, how does an orthographic projection of the celestial-sphere lead to a
>> justification and explanation of the construction of a Capuchin or
>> Universal Capuchin dial?
>>
>> Can anyone here explain that? If so, the explanation would be appreciated.
>>
>> Michael Ossipoff
>>
>> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
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Re: Construction-Principle of Capuchin & Universal Capuchin Dials

2017-05-10 Thread Yvon Massé 

Michael,

Some years ago, I spent a lot of time to search a simple geometrical 
justification of these kind of dial. The best way I found is:
- for the Capuchin: from the orthographic projection of the celestial 
sphere on the local meridian (fig. 1)
- for the Universal Capuchin: from the orthographic projection on the 
hour plane of the Sun (fig. 4)


These figures are detailed here:
http://cadrans-solaires.scg.ulaval.ca/v08-08-04/pdf/XIII-4-p10-4.pdf

and the links between the figures and the dial are briefly explained here:
http://gnomonique.fr/divers/anal_3_angc.pdf

Of course, it isn't quite simple but, perhaps, you will find some 
interest in these articles.


Best regards

Yvon


Le 09/05/2017 20:50, sundial-requ...@uni-koeln.de a écrit :


I'm not asking about the *instructions *for constructing Capuchin and
Universal Capuchin dials. I'm asking about the principle, the explanation,
the justification, for their construction.

Some websites have said or implied that it has to do with an orthographic
planisphere. I'm familiar with the use of a universal planisphere, an
azimuthal projection of the celestial sphere in equatorial-aspect.  ...but
it isn't entirely clear how that relates to the Capuchin dials.

I found a handwaving explanation on the web. I've pasted its diagram, and
some of its "explanation", below in this e-mail.

The explanation says that the diagram below, an orthographic projection of
the celestial-sphere, looks just like a Capuchin dial.  And that's supposed
to be an explanation.

So, how does an orthographic projection of the celestial-sphere lead to a
justification and explanation of the construction of a Capuchin or
Universal Capuchin dial?

Can anyone here explain that? If so, the explanation would be appreciated.

Michael Ossipoff


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Construction-Principle of Capuchin & Universal Capuchin Dials???

2017-05-09 Thread Michael Ossipoff 
I'm not asking about the *instructions *for constructing Capuchin and
Universal Capuchin dials. I'm asking about the principle, the explanation,
the justification, for their construction.

Some websites have said or implied that it has to do with an orthographic
planisphere. I'm familiar with the use of a universal planisphere, an
azimuthal projection of the celestial sphere in equatorial-aspect.  ...but
it isn't entirely clear how that relates to the Capuchin dials.

I found a handwaving explanation on the web. I've pasted its diagram, and
some of its "explanation", below in this e-mail.

The explanation says that the diagram below, an orthographic projection of
the celestial-sphere, looks just like a Capuchin dial.  And that's supposed
to be an explanation.

So, how does an orthographic projection of the celestial-sphere lead to a
justification and explanation of the construction of a Capuchin or
Universal Capuchin dial?

Can anyone here explain that? If so, the explanation would be appreciated.

Michael Ossipoff

[image: Inline image 1]
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