The trails, tribulations, and joys of designing & making  a Cornelius Varley ( an Englishman ) telescopic camera  Lucida for the
American Philosophical Society
Jim and Rhoda Morris  781 245 2897 Email   Email

Benjamin Franklin,  a self taught civilized man of humor and thoughtfulness, founded this society in 1743 thereby connecting the Arts and Sciences in such a way that the expense of the learning experiences gained could be shared by its members and at least by some of the  community. An achievement even before our American political revolution. The perseverance of science and the tradition of Ben's sprit continues today.  We are pleased to have participated in one of these connecting programs.  This note tells our part of the behind the scenes stories of building an English Varley Patented Graphic Telescope Machine using parts from an English  made telescope,  redesigned with American adaptability,  assembled near the American revolutionary town of Boston for the World to see.

The picture above shows  the location of the American Philosophical Society Museum amidst the buildings of the historical Independence Hall complex in Philadelphia.  A wonderful collection of symbols for how to run a community, a country,  studying the laws of Nature and nurturing the laws of Civilization.
In the center is the director and curator of the museum, Sue Ann Prince, admiring the Varley graphic telescope we built for them and anticipating the joy their visitors will have in using and learning from it.

Cornelius Varley was an artist, astronomer and scientific instrument designer and builder, bless him.
He developed and built Lucida type graphic telescopes to allow scientists and artists to produce more precise drawings and paintings of distant natural and artistic subjects reaching to mountains and stellar objects.
He also adapted his instruments to microscopes giving a view into the wondrous and complex world of tiny objects, satisfying our scientific curiosity and aiding us in artistic studies.
His instruments render a wider and deeper scope of nature's world for all of us to see and wonder at.
He achieved this feat at a time before cameras were available.
He left, actually willed, this still remarkable drawing aid for those who want to reveal the artistic view of  nature.
And not of least importance, his instruments can be used for just plain fun for seniors and juniors alike, as shown below.

Each of us plays an important role in society and our  views can be expanded and shared by using this type of  instrument.  Here is one small chance to see nature in action and pass along what we see and learn. One can search out and study each detail as we trace the object we we see in the telescope at the same time recording it with our fingers holding a marker on the table below. We then have the joy of learning about the object in greater detail and sharing our experiences with others.

Purpose of this Web Site:

This web page has been put together by Jim and Rhoda Morris.  Our intention is not to organize it as an instruction book on "How to make a Varley Lucida type graphic telescope in 20 easy lessons or less" although one might, in practice, be able to use it for that purpose.  So what are these pages about?

We hope by furnishing our records, our experiences and our pleasures in building this working example of Varley's instrument for the public's use, that we will also be carrying on, in one small part, the tradition of Varley's work and his wonderful instruments. The opportunity of being a part of such a story can be envisioned by roaming through of our notes, pictures, discussions, descriptions, and videos of the issues we dealt, the instruments involved and especially the people we worked with as we built the Varley telescope.  Our presentation is an informal tour that also shows how the Varley telescope is a further and much broader development of the camera lucida invented only s few years earlier. 


Kristen Frederick-Frost

was our principal and very helpful working contact at the American Philosophical Society. Here she is standing in front of one of Varley's telescopes at the Franklin Institute. We were making detailed measurements and took photographs of the essential parts of the eyepiece we needed to replicate.

Kristen and Rhoda
in another setting another time and project. We are at  England Rhoda and Jim were in the process of getting data for another film the Mystery of Matter where we were replicating an apparatus used by Henry Gwyn Jeffreys Moseley in his classifying of elements for the periodic table and experimental evidence in favor of Niels Bohr's theory. We met Kristen here while she was at Oxford University.

Our goal was to help continue the odyssey of a famous era in both science and art by repeating and adding to this saga of science and its adventure. It is more than just a log of our consultation with the museum staff about our progress and decision making process. This material, hopefully, can be appreciated as being a part of a continuing journey through the history of the arts and sciences to today. One that can be realized by those who are fond of both. Some may also appreciate getting an insider's view of what it is like to be an active part, a member, of this process.


In the beginning our question was:

What was Varley's main contribution to the science of the art he was endeavoring to produce?  The answer is:
The basis, the very heart, of Varley's instrument is a 'mirror knife edge' that allows the observer's eye, when placed as close as possible to the eyepiece, to simultaneously see the object and the drawing stage where he or she can copy it.


We were delighted but over booked when asked to build a Varley telescopic camera Lucida. We already  had considerable experience with these sort of projects. They are always delightfully accompanied with trials and tribulations when replicating very historically famous  instruments.  This instrument was needed for the American Philosophical Society Museum's (APS) summer / fall 2013 season exhibition.  There were many conditions to be met. First of course, it had to fit the museum's delivery time, its budget, and its safety demands.  The instrument has a very sharp edge on the image divider which is very close to the eye when the user is copying the image. The construction of the instrument had to meet as close as possible all the fabrication styles and components for that period. Most importantly it had to operate just as if it were an original Varley instrument.  It also had to survive the untrained handling of the instrument and its delicate parts by younger visitors.

And there were more.  There was the  issue of  redesigning, developing, adapting the optics in this telescopic version of the camera Lucida to take into account the museum's space constraints when used inside and still have it be useful for distant objects if and when it was taken outside. NOTE that in general telescopes are designed to bring distant objects close up, not close up objects closer up. Also the eye relief had to be extra long to provide room for the critical distance between the eye and the first lens.  Our independent research was absolutely essential

Analogy to the Camera Lucida

 As for the issue of the basic component that makes the Varley instrument work, the knife edge, it has a similar function as the prism in the camera lucida for simultaneously seeing the object of interest superimposed on the drawing.  Start with the very confusing  photo above.   Refer back to it while looking at the  much copied art work below for how a camera Lucida works. Careful, careful!  NOTE, look for the classic faults in this historic drawing of scientific instruments.  Artists have to only use creative license to do their best work, by contrast scientists get fired if their device doesn't work.


The drawing of the optical ray paths has misleading errors in it.  Can you spot  them?
Jim & Rhoda Morris  781 245 2897


Camera Lucida

From Wikipedia, the free encyclopedia

1830 camera lucida is an optical device used as a drawing aid by artists.

The camera lucida performs an optical superimposition of the subject being viewed upon the surface upon which the artist is drawing. The artist sees both scene and drawing surface simultaneously, as in a photographic double exposure. This allows the artist to duplicate key points of the scene on the drawing surface, thus aiding in the accurate rendering of perspective. At times, the artist can even trace the outlines of objects.


Below: are nine photos of our Camera Lucida from our collection which we had the pleasure of  loaning to the  American Philosophical Society Museum  followed by series of photos of our process of replicating Varley's telescopic graphic camera lucida for their exhibition.

1.  Prism and peep sight


2.  Side View of  prism


3.  Camera Lucida set up on drawing board


4.  Top view


5.  Clamp for fixing the Lucida to drawing board


6.  Another view


7.  Folded up ready for packing the unit into its carrying case


8.  In the carrying case


9.  Inscription on clamp


Building the Varley Patented Graphic Telescope

In addition to providing our camera lucida  described above,
below is a photo of our finished replica of a Varley Graphic Telescope for the American Philosophical Society Museum. It is pictured  going  through it final test run in our  garden before its delivery.

We follow this with a series of very interesting photos and notes taken during the rebuilding of the period Spenser Browning telescope  to a Varley telescope by replacing the Browning eyepiece with the complex Varley eyepiece and modifying the objective end for perpendicular and closer viewing of objects.

 The start and the  finish of the instrument.

 Varley's drawing of one of his suggested wooden folding apparatus for holding the telescope holder. As one can see from the  photo below we chose the one in this drawing  to replicate.  A page out of Varley's patent showing the details of the eyepiece lens including the knife edge mirror, and  its mounting. Instruments rarely follow the patent drawings. Varley was all over the place. His drawing and sketch were over a large range of topics and  brilliant.

To meet the budget  requirements without straying too far off from the details of the telescope  we chose a  super fine Spencer Browning telescope of the same period. It needed  some cosmetic repair, but had an extraordinary optical system and performance ideally suited to the Varley needs.  Our license in this matter was that Varley made a fairly large number of telescopes and the ones that still exist have physical appearances and construction all over the map in size and construction.  The principal difference  between our telescope and existing Varley scopes is that the one we substituted does not have a smaller diameter at the objective end than the body. Another  possible justification in the agreed substitution was that Varley could, and probably did, use a standard telescope for his starting experiment with his knife-edge mirror.  Wouldn't it be satisfying if he used the same telescope we  have chosen? 

 Below are photos of the original Spencer Browning telescope we used and its conversion to a Varley type Graphic Telescope:

1Below,  The  telescope lens section of the Browning partially extended and the beginning of the disassembling of the eyepiece.

2.  Exiting Spenser Browning eye piece partially unscrewed  and drawn from telescope.


 3.  The two lenses  in the eyepiece to be used in the conversion to a graphic telescope


4.  Same as 3 with eye multi-lens eye eyepiece piece lens removed from its holder


5.  Objective end with hood pushed back to expose the lens. We will have to construct the
rotating  mechanism for holding the forty five degree precision optically flat surface mirror.

6.   On the right is a photo of a collection of Varley lenses and an example of one of many body types
he used to hold them. In the middle  a piece of brass stock, 2 3/4 inch dia 12 inch long,
of which a 4 inch long chunk will be used for make the eyepiece. Further on one will see the reason for this chunk of brass.


Below are Notes and Measurements: furnished to the American Philosophical Society Museum during our work.

a. We made arrangements to restore the  leather covering on body of  the period Spencer Browning & Co. London Day and Night  telescope.

b.  Rough magnification measurements of said scope is about 10 plus power, 4/06/2013

c.  Focusing distance of telescope is 10 feet (from objective end) to infinity. Minimum focusing distance is about 14 feet from eyepiece end.

  d.  At a distance of 10 feet from the objective, the maximum field of view is 4.5 inches  ?????


7.   Photo of Franklin's PGT 011 from Kristen's email 3/25/2013. 
Below it  is superimposed on a photo of  the Spencer Browning telescope eyepiece, from photo # 2 .



8.  Comparison the physical fit between the two eyepieces by superimposing  the photo of the 
Franklin PGT 011 (white outline) over the Spencer Browning eyepiece (see our photo #2)


9. Top photo displays a number of Varley eyepieces and one of the many telescope bodies he designed.
      We show this because Varley made many different models justifying our use of an equivalent telescope
                        which at little to no loss of integrity enabled us to decrease the construction time as well as be more cost effective.
               The bottom photo shows the roughed out conical portion of our model of Varley's  eyepiece on its way to the final stage. 


           10.   Top photo shows another view on left of our  roughed out cone for the replica .  On right
are  parts of the  original telescope we are adapting. Our changes will be reversible.
              (The cup of tea at the top of the photo had been set out in case Varley's spirit stopped by for
                                   a visit. Note the cup sort of  hovering above without any visible support. Is that a bit of star dust sprinkled
about the photo?  hmmm (-:

11. Close up Rhoda measuring the field of view and the shortest distance from objective to the telescope
             with and without the extender objective lens. This was very important  to shorten the distance
                     between the telescope and the object  to allow the telescope to be used inside the museum which
was a little shy of available distance.


                      12. The  tripod holding the scale for measuring the field of view and the shortest distance from objective
                                 to the object with and without the extender objective lens.  To the left  on the table is the roughed out eye
piece for holding the eyepiece optics of the replica .


Below are Detailed Pictures Showing the Fabrication of the Varley Telescope Eyepiece Fixture

below cutting the "V" slot in the knife edge mirror fixture.

Above,  The knife edge holder roughed out. The inside detail for holding the primary lens is finished


 Above,  Cutting out the v slot for the mirror knife edge fixture.


Above is the the Varley eyepiece holder being turned in our lathe to its conical shape.


Above, the heavy ball is holding the parts together for  silver soldering of the eyepiece.


 The finished Varley lens components  minus the mirror assembled  and prepared for finishing.


      Above is a comparison of the Varley and traditional lens that came with the telescope.
Either could be used preserving the original telescope. An important requirement in handle important instruments of the period.


Prototyping the  telescope stand. Jim and our "bestest" oldest daughter designing and making the telescope table and stand. Checking the critical eyepiece with its  knife edge to be installed .  Checking  and designing the eye relief. system. It needed extra distance built into lenses, compensating  for extra distance taken up from  the right angle view.


The top most lens fixed on the original objective was our removable field distance shortening lens to let the telescope operate in the short distance available in the  museum.*** This lens was an exact copy of  Galileo's working telescope which we replicated  for the Galileo Museum in Florence Italy.

 An optically flat right angle mirror for adjusting  height angle of view. It is out of glass not speculum metal which probably used by Varley. The   sun shield  and  mechanism for holder the rotating optically flat  mirror.

We have  hundreds of photos and video recordings of the construction, testing, and designing of this remarkable instrument.
 The results were beautiful and technically very good because of the initial design by Spencer Browning .

All photos and written material are by Jim & Rhoda Morris unless noted otherwise.
Free personal and educational use and reproduction is encouraged---
Acknowledgment is appreciated; all commercial rights are reserved