M&D: Twin Telescopes and Transits

[David Ewers]

If Transit of Venus:  (viewed as a sequence of points, with each new point determined by the last… to describe a line…like a survey?)   was used to determine solar parallax (and from there the distance from Earth to the Sun), and parallax is defined as a difference between two lines of sight:
If M & D represent a (human) parallax-viewer - like those "twin telescopes" (...or Keplerian binoculars, with their image inversions!…North/South, anyone?...), and the M/D line is a sort of transit, then there's a (human?) parallax being determined?  A (human?) distance being calculated?


Binoculars with Keplerian optics[edit]
An improved image and higher magnification is achieved in binoculars employing Keplerian optics, where the image formed by the objective lens is viewed through a positive eyepiece lens (ocular). Since the Keplerian configuration produces an inverted image, different methods were used to turn the image right way up.
Binoculars with erecting lenses[edit]

Cross-section of relay lens assembly - System 2.
In aprismatic binoculars with Keplerian optics (which were sometimes called "twin telescopes") each tube has one or two additional lenses (relay lens) between the objective and the ocular. These lenses are used to erect the image. The binoculars with erecting lenses have a serious disavantage: their length is too big. Such binoculars were popular in 1800s (for example, G.& S. Merz models), but became obsolete shortly after Karl Zeiss company invented improved prism binoculars in 1890s.[3]

On Jan 15, 2015, at 1:57 PM, alice malice wrote:

> Not from Sailing to Philadelphia but still...
> 
> https://www.youtube.com/watch?v=6fMrMTerVSg
> 
> On Thu, Jan 15, 2015 at 6:31 AM, Kai Frederik Lorentzen
> <lorentzen at hotmail.de> wrote:
>> 
>> https://www.youtube.com/watch?v=ncjvrtZoSRk
>> 
>> Tanz-Orchester Tauber (1919): Cross the Mason Dixon Line
>> 
>> -
>> Pynchon-l / http://www.waste.org/mail/?list=pynchon-l
> -
> Pynchon-l / http://www.waste.org/mail/?list=pynchon-l

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