Galileo Telescopes' Very Unusual Construction. Precisely Replicated for Griffith Observatory and Adler Planetarium.
Jim & Rhoda Morris   of  781 245 2897

Details of Galileo's 2428 telescope  original and its replica made for Griffith Observatory is covered in great detail in this website. Many details  covered are relevant to the 2427 as well.
Click Here  for Galileo's 2427 telescope original and replica made for Adler Planetarium Its covered in great detail on its web site
Click Here  Dimensional errors in the literature of Galileo's telescopes required us to go to Florence Italy and make measurements of the original.
Click Here A more detailed analysis for errors in the literature especially in  the optics and what one really see's when looking through Galileo's telescope is demonstrated and discussed.
Click Here  for a more concise discription of these two telescopes

A First *** Below What Galileo's Telescopes Most Likely Looked Like When They Were New!
There Are No Words Powerful Enough To Express The Importance Of Basic Scientific Research

Click on the telescope to inlarge it then click on the image again to in large it  to 2469x277 pixels
A large picture of Galileo's telescope IMSS # 2428
Click on the hyperlink to see the original   IMSS INV #2428
Stay on this site to look at the detail of replicating this telescope IMSS # 2428

Click on the telescope to in large it then click on the image again to in large it  to 2558x147pixels Picture of Galileo's wood and paper telescope IMSS2427
Click on the hyperlink to see the original  IMSS INV #2427
Click Here to go to our web site covering this telescope IMSS # 2427.

Picture of replica of Galileo's red leather telescope IMSS2428
This telescope is hand made and based on  data we measured from the original at IMSS Florance Italy. It has over 100 pieces. It is covered with leather which is embossed with pure Gold leaf  using over 20 dies, faithfully following the impressions of the original, with 400 individual gilding die strikes. It is truly a striking work of art as well  as a tactile time capsule giving one a feeling of awe while handling it.  It is  a superb teaching tool.. The telescope is so similar in every detail to the original that it's like stepping into a time machine and journeying back into the past. We even felt a little nervous while filming a church steeple scene through our telescope for the TV Discovery Channel wondering whether an official from the church might take an  overt interest in us and our telescope!
During our research and fabrication, which took nearly a year,  Galileo's guiding  sprit always seemed to be with us. For those who care,  he was very good company, handy around the shop but had a mischievous sprit as one  might guess from the twinkle in his eye.

  Last Revised 06/19/2009 06:59:49 PM EST


Above a direct comparision of our replica of IMSS 2428 with the original  at Florence Italy

This web site is large with many  pictures and discussions. It contains three major topics.

1, The construction details of our replicas.  The details of the originals at IMSS Florence Italy .
2, Why these telescopes are so important as  teaching tools in today's environment and why we have worked so hard to make them as close to the originals as possible.
3, One of our goals has been the development of a clearer understanding of Galileo as a technologist as viewed by two modern day professional technologist  a comparison of the stark business of science then and today.
4, Its been a fun project. We no longer have to look at the beat up war weary  400 year old instruments. We can now seen and truly appreciate them as they looked when Galileo was using them.

We have replicated, with great care, Galileo's  two internationally famous Telescopes. We based our replicas on  data we measured from the two originals which are attributed to Galileo and are on display at  IMSS in Florence Italy. We constructed  INV # 2428. complete with its gilded leather covering  even  duplicating its  very unusual  thin-stave internal construction, something that has not been done before.  We made this instrument for the Griffith Observatory for their 2006 renovation. We also constructed INV#2427  The equally interesting laboratory type telescope  for the Adler Planetarium. It has a split wood tube  covered with paper painted  and reinforced with copper wire bands along its barrel. We took great care with both telescopes  reproducing each part of the instruments  to be as  close as possible to the originals. Each telescope was  assembled  by hand as they were in Galileo's day. Our  dimensional accuracy has been kept to within a few percent in all cases and in some instance's to  fractions of a millimeter of  the  originals. We also chose not to antique them but to show them  as they would have looked when new.

Our replicas are   accurately reproduced therefore  particularly useful  as research, teaching, and display tools. One can see, feel, and operate them as Galileo saw, felt and operated them. This tactile experience high lights more accurately  their virtues and their  faults giving  a more mature insight into 1609 telescope making and operation that Galileo, his associates and customers experienced.

The telescopes are high museum grade replicas and very rare.  The leather covered telescope, the  replica of  IMSS inv #2428, has over 100 pieces  and  is embossed with over 400 gilding die strikes. It has  very unusual construction features both inside and out, with an  optical power of 21. The replica of  IMSS inv. 2527 represents a construction style commonly used in research / field grade telescopes for that time period.  It has nearer 17  pieces and  a power of 14. The pair complement each other, one a presentation piece designed for people of power and influence ,the other a field type instrument for  customer or colleague.

Achieving  this high level of accuracy in the reproduction of these telescopes was through the patience and  very professional help of  the staff at IMSS in Florence Italy, the staff of the Griffith Observatory, and the staff of Adler Planetarium with their interesting replicas made by Cipriani. They made it possible for us to make measurements and make   high resolution photos of  the originals and some Cipriani replica telescopes. They also shared  their considerable experience of  these instruments with us.

We found It was absolutely essential to  make our own measurements of the original  having found a number of important differences in the data for dimensions and materials in the  published literature  and   some exiting replicas. We made a concerted effort in checking and cross checking our data  in  resolving  these differences.  It is important to note in our comparison that we distinguished data between Galileo type telescopes and those reporting to be Galilean replicas. For those instances where there was no data  such as the  eyepiece holder in IMSS 2528 we made and noted our best guess.  based on our
technical experience  which is considerable. Last but not least  In the virtually all cases it is  possible to make simple modification to our replica telescope if necessary to accommodate any  new  and more reliable information  if it becomes available.

The bottom line is that our replicas are the most accurate and finest made to date and will hopefully serve as  standards for other replication in the future.
From our technical point of view researching  and building a number of Galileo instruments we saw Galileo and his telescopes as remarkable and timeless examples of what the business of science is  all about.  Galileo and his instruments is a  first rate case study of science, technology and its support. There is much to learn for our future from his story and his instruments but  we  first  have to deSobelize our selves.  Below is an outline and some simple, at times stretched, examples of Galileo practicing technology as seen from  fellow technologist point to view.

One will  find faults some gross (most are Jim's) in our grammar our spelling 
and we apologize for them. Our choice of examples and our reason for making them we believe are  solid,  We can only hope that you the  reader  gets at least an inkling of how important this case study is.  That it helps  us understand what basic research is all about, how important it is and that it will  encourage  some to join the effort of bringing the
Galilean Syndrome under control so our scientist can bring  us to fuller understanding of our selves, the  universe we live in and depend upon.

Most scientists we hope will  recognized  themselves in many ways as the Galileo's  of today.
We encourage those who have been taking a back seat to come forward and help.    TLM.

We have made two of each of these telescope one for our collection and the other for the museums
. They have been well received along with our discovery of the  Galilean Syndrome  by magazines, TV programs and talks at Harvard Observatory and Bunker Hill College    See the photos below.

For those with the professional interest we will be making a  few of these very precise museum grade  replicas  for museums, serious collectors and those who so kindly donate instruments of this quality to their favorite museums and other teaching institutions.   If  interested please  contacted us at or 781 245 2897 for more details.


Links   to Galileo, His original telescopes and replicas

Replicating the laboratory telescope
Building the Laboratory Telescope for the Adler Planetarium The Original  IMSS INV # 2427   

Researching and Evaluating the Literature
for the dimensional data needed to build the replica
The data for precisely replicating  these telescopes. 

Will the Real Galileo Galilei  Please Stand Up Please

The Construction data  and details of IMSS 2427 red leather telescope
Galileo's Original telescope in detail disclosed a unique resin composite construction.
The telescope optics important choices

Overall length of telescope determined by the optics and making them.
The over all Important art work


What Does All This Mean, Why Should We Care, Galileo as a

Basic research scientist, 
Applied scientist,
Engineer and product development

The Galilean Syndrome
The Value of Basic Scientific Research
Photos of our telescopes being used

JJim & Rhoda Morris  Comments invited, e-mail  781 245 2897
06/19/2009 06:59:49 PM Latest up date 

Below  a photo history of our replicas

Dr. Giorgio Strano - Curator of IMSS, the museum where Galileo's telescopes are kept on display. He  is looking out over Florence's roof tops  from the top of IMSS building,  using our  precisely made  replica of IMSS 2428 just as Galileo Galilei might have done with one of the original telescopes some 400 years ago.

Rhoda co builder of our replica checking out the quality of the image

Dava Sobel author of the  very interesting book "Galileo's Daughter" looking through our replica sharing the experience that Galileo would have had using his telescope. The photo was taken during  the conference of the  History of Astronomy Workshop at Notre Dame July 2007

The  replica of Galileo telescope we fabricated
now at  the very beautiful Griffith Observatory ready to do its job for the museum's staff  to help you appreciate and learn even more about the value of science. It's ever so gently  being
held by Mark Pine the Deputy Executive
Director of the "Friends of  The Observatory".

The  replica  telescope we built  on display at the Griffith Observatory We  copied  the photo from  The Wikipedia
We touched up the photo 

Michelle Nichols Master Educator Adler Planetarium & Astronomy Museum in Chicago Illinois  checking out  Adler's new replica of Galileo's telescope IMSS 2427. which was   precisely made  to the specifications of Galileo's original telescope.


Below  an extraordinary set of photos showing the world's most exact and complete replicas of the two existing Galilean Telescope at IMSS mounted together on a working modern refractor. In the center are the originals at IMSS Florence Italy.

Click here to see additional details  of the mount used to hold these telescopes


Eyepiece end The originals at IMSS Florance Italy Objective end. The telescopes were ,mounted on a modern refractor for comparing the images and illustrating the mechanical differences.

Samples of the Media's Interest

The objective end of our replica showing the  layers of planking that make up the lens holder. The gold decoration has not been applied yet.  Steven A. Simpson photographer of the magazine "Night Sky" taking picture of the  objective end of our replica without the gold decorations for an article by Jim Quinn "Stargazing with Galileo". May/June issue "Night Sky".

One of our replicas is at the Griffith Observatory the other is playing its  first acting job of the history channel. Below are some pictures from the set of History Channels  "Man Moment & Machine"

One of our two replicas of Galileo's Telescope being filmed on set for its first public appearance on Cable TV From left to right are director of photography Boyd Estus of Heliotrope Studios Ltd., Hunter Ellis host of the History Channel's "Man Motion. Machines" Series and Rhoda and Jim Morris of co-maker of the telescope


Note the Camera/Telescope set-up for filming the image as actually seen through the replica of Galileo's telescope We had to make a special mount to couple the very fragile very rare 12 oz telescope to the very expensive 42 pound camera to give the TV audience a feeling for the image quality Galileo worked with as he scanned around the neighborhood through the astounding instrument that brought the "far away so much closer"

Filming one of the scenes of Jim Morris and Hunter Ellis chatting about Galileo's telescope and how it works


The crew Gathered together watching the monitor displaying the image from the telescope Third from the right is our Producer/ Writer of the History Channel 's Man Moment. Machine Julie Mirocha. Rhoda is taking the picture.

Meet the principal members of the replicating team

Jim basic and applied research physicist on temporary duty as apprentice to Galileo.

Rhoda Basic and applied research chemist on temporary duty as apprentice to Galileo.

Galileo Senior member of the team working toward getting  more  help for funding and more   support for  basic research.



While researching and replicating  Galileo's Telescopes  We discovered another replication  that was taking place, which was  the replication of  the lack of support  of basic research in science today just as there was lack of support 400 years ago.

Galileo's story on an international bases is  a well documented case study, reminding  us  that these  telescopes  stand as  symbols  of  a long held  prejudicial miss understanding against basic research. 
We are all victims  waiting on  the side lines while the various factions in this  debate  work out their differences so that we can get on with the basic scientific research and turn this knowledge  into ways that will give us   a fuller, healthier, safer life as it already has shown that it can do.

The authors suggest that Galileo---- this one man---- and his telescopes  represents in a simple, elegant  and dramatic and  important way,  all the aspects of what technology and its mistrusting antagonists are about in 1600 and to day. One is compelled to ask Isn't it the time for both sides to work together to gain a better understanding  of each others point of view with data so we can work out a compromise  that we can  resolve  this dilemma and  we can get on with the research we all so badly need.

There is a beautiful case study buried in  this 400 year old   story that is both unique and valuable because each phase of the complex and often hidden important business of doing  basic research is all  rolled into one type of instrument and one  scientist. All the tasks of doing science are being   played by  one actor, in a one act, one prop play   with  Galileo playing  all the parts. Today research is done by teams of scientist and  has  become very complicated to extract out the many steps needed to understand  how  discoveries are made and used i.e.  the business of  basic scientific research. Unfortunately the dialog for such a  play  is spread thought out the literature filled with errors of a personalized nature waiting to be complied into a single script  minus all the media melodrama that clouds the issues.

This web site suggest that Galileo's story as told through the telescopes can stands as a mile post  showing us what is going on today by looking at 1600 AD  and measuring our  progress  and understanding of this  prejudice  that sadly  still exist today, which we call the Galilean syndrome.

400 Years Ago 1600
A dramatic picture, a dramatic story, a dramatic lesson for all of us In the 21st century

News flash
Warning:  Pernicious Galilean Syndrome, a dangerous myopic anti science disease is again infecting our society


400 years later 2000 +
A dramatic picture, a dramatic story, a dramatic lesson for all of us In the 21st century

News flash
James Hansen, director of NASA's Goddard Institute for Space Studies  on trial before the U.S.  congress for warning the public that  man is making the earth  dangerously warmer. If  true who will be faced  being burned at the stake this time?

One of the country's leading climate scientists, has testified "the White House (Politicians & Oil Companies) repeatedly tried to control what government scientists say to the public and media about climate change."  It has been reported that 181 changes were made  by non science political appointed officials,  to three scientific climate reports reflecting a consistent attempt to emphasize the uncertainties surrounding the science of climate change and undercut the broad conclusions that man-made emissions are warming the earth. Hansen also said "Interference with communications of science to the public has been greater during the current administration than at any time in my career,"
Warning:  Is the Pernicious Galilean Syndrome, a dangerous myopic               anti science disease  still infecting our society?


Symbols of Progress and the Galilean Syndrome?  

The Galilean Syndrome

Galileo's telescopes  are especially important today because they stand out as  symbols  warnings  us to keep   constant vigil against those that would  turn us away from science, its methods and tools.

The Pernicious Galilean Syndrome its always there!
The support and funding of basic scientific research so vital to us in the U.S. and the world, has come under attack again by a few powerful, charismatic,  zealous, leaders  repeating the same mistakes of myopic  judgment  that  Galileo  had to contend with 400 years ago,

In spite of science's success it is always vulnerable to influential misguided leaders ready to summon their followers to take our basic scientific research away from us. These followers go after their congresspersons threatening their reelection for supporting science. Although relatively small in number they are well organized have proven to be very effective.

Scientist  can not solve  the  problems they are given without adequate funding. They need our help and support.  There are so few scientists compared to the world's population including the very active dissenters that their warnings and cries for help are too weak to be heard by the general public.

The cure  for
Pernicious Galilean Syndrome takes less than five minutes a year; Most of us do not appreciate that we are  automatically part of the science team.  We  don't need a degree in science or take courses in science to be a  very important contributor to the progress of

The Beautiful Home of Galileo's Telescopes

science and their are allot of us on the team.  However, we do need to stop taking science for granted and we do need to  actively start supporting  it!

As members of the science team we have a vital role.
We need to bring to the attention of our congressman  the  critical need for our government to strengthen its  interest and support for  basic scientific research.   All aspects of our future depends on it.

Yes most of us understand the value of basic scientific research.   Yes we are large in numbers, and want it supported, but we must be vigilant, contacting our congressman showing our support in numbers that at least match the dissenters.

Galileo's famous and dramatic telescope story is repeating itself today and we as well as the dissenters are the victims of this Pernicious Galilean Syndrome.

In the foto above is part of the team  Jim & Rhoda, best of  friends, husband and wife,  grandpa and grandma, physicist and chemist, hanging around  Galileo's neighborhood.  Here we are in front of  the extraordinary museum where Galileo Galilei's telescopes, his other famous instruments, and his index finger reside.  The museum lies on the banks of the beautiful Arno River in Florence.  Galileo  is  buried just down the street and  is still teaching science (and the danger of  Pernicious Galilean Syndrome) to the public visiting his stylish crypt in the  Santa Croce Church.  He and his telescopes are still in there fighting for science. Don't let him down. Join him in the fight

More Detail on how you can help


Detail on how you can help

More Detail on how you can help

Galileo and his telescopes the important technical and cultural issues surrounding them in1609

Our goal  is to help readers to enjoy the new information on the construction details of Galileo's telescopes  their  optics and  the  scientific anomalies that Galileo dealt with in designing and building his high powered telescopes i.e. why he really developed them and how.

Even though there is a 400 year time gap between Galileo and the authors . we  found ourselves being  drawn into a close personal and professional  relationship with Galileo or at least his spirit while working on the replication of his telescopes   He seemed to always be at our side judging our work piece by piece even the inner most details of his instruments. Galileo grew into more than  a colleague for us, but a friend with an agenda of pushing us to build his telescopes to the highest quality standard so  they might act as symbols of one of  sciences most  dramatic stories  highlighting the dangers to our science from  leaders endowed with poor judgment in matters of science who assume  control of our science. to our detriment. When we shipped our replicas off to Griffith observatory we felt very much like we were shipping the spirit of Galileo  with them. When they were gone our shop/lab felt strangely empty. It was only after our telescope returned from its journey to California and back and we could give it a little pat now and then that the lab felt more complete.

Our web site  takes you on a step by step tour of the construction, the surprises and the frustrations of building a truly precise and high quality  replica for  very high quality museums. We take you on tour into bowels of the telescope wherevery very  few have been before. Experience the personal design and political choices Galileo built into these telescopes and why.

We provide for you  a very rich example of what it is really like to look through Galileo's telescope  and you will be shocked at  the  very tiny speck of light  from a  window  far off in the distance of  a very large  dark cavern. You will develop a  great respect for Galileo's masterful skills as the first observer of the heavens, seeing them as no one else had ever  seen them before.

The following section speaks to the techno-political issues of why  we feel that Galileo and his telescopes are so important in today's environment. We state the ground rules we  set for ourselves in this project, and give what we feel is a a more experienced informed look into Galileo's  technical and judgment skills. We also express our views of Galileo's most important and unique contribution  to to days science which goes far beyond his celestial discoveries.

Back ground information for studying  Galileo's Technical decisions

The following section gives a brief  a description  of the technical environment, the tools that were being  used to explain how nature worked that Galileo struggled with in earning a living

The Nonsense of Common Sense Is it in our Gene's?

We start with  comparing the tools of common sense used in 1600 with  tools of the scientific method during its earlier stages of its development.

A statement and a question. Two lenses plus a narrow cylinder three feet long, with a total weight of less than a 12 ounces is all that one needs to build a Galilean telescope, It seems so simple yet caused so much trouble for a major church of the day and the scientific community. Lenses had been around for centuries as eye glasses. Why weren't higher power telescopes invented earlier?

 The following example is certainly part of the answer. Below we give two  simple demonstration of the old way "common sense" was used to solve or couldn't solve problems and how it came to be recognized as the non sense of common sense which was contributing toward the slowing of the progress of finding out how things really worked.

Up until the time of Galileo common sense was virtually the only tool of choice to explain how things worked. Some people might like to call it logic?. Common sense had the advantage of being simple to use. It was a one liner tool that anyone  used  It didn't take much work to make up one liners. Using common sense one didn't need to take hours making quantitative repeatable measurements to take a position of authority. One didn't need to have your competitors review your conclusions for flaws in measurement and reasoning because there would be no reliable measurement. You didn't need them. You just used common sense with the right tone of voice or pen.

1 st.  example Lets look at a simple example being dealt with in the religo---techo commonsense debate going on at the time showing  the type of common sense that Galileo and those that were around him at the time had to deal with.

  • It was common sense that told us that the sun went around the earth.
  • Everyone could see it go around.
  • Everyone with common sense knew that it was very hard to move  rocks to build a pyramid and it would take allot more  to move the earth.
  • Obviously the earth was just too big to move.
  • Besides you would feel it moving if it was .
  • One could see that the sun was smaller so it had to be the sun that moved.
  • Mathematical formula which very few understood suggested that the simple retrograde motion of some of the planets could  be explained if every thing went around the sun but common sense told many that  mathematics' could not be trusted, which most believe to this day especially when it comes to statistics, and they say it with great gusto and assurances.

On and on with reason after reason It was just common sense ...... 

2 nd. example, The Politics of Optics Galileo the Engineer and Entrepreneur

Galileo as a businessman; The authors comments on The business of basic research 1600 and 2006

The challenges of replicating  Galileo's existing telescopes and judging his technical skills requires a  perspective of why he was building them and for whom he was building them. This knowledge is critical in judging Galileo's skills as a Scientist/ Engineer/Entrepreneur. (Yes we have to remember that Galileo was an entrepreneur earning monies to support his research and family needs just scientist do today.) The decorative red leather telescope and it negative lens with its limited field of view but upright image most likely was an experienced business decision on Galileo's part.  The red leather telescope should be  considered as  part of his  product line of technical instruments for sale or bartering. The very beautiful art work would hardly have  been put on one of his data gathering instrument for his own research. Its seemly compromised optical design  the poor field of view yet high magnification with a short over all length reflects  his customer needs not a design flaw from a lack of Galileo's skills in optical design as some have suggested in the literature.


What was the challenge to Galileo as he designed his high powered telescope? How did he do it?

Below are three remarkable  experimental observations where common sense seemly makes no sense when it comes to optics. Here Galileo used the scientific method in designing his telescopes to get past this anomaly  created by ones visual senses.

1 st. observation of the magic of lenses; The lens on your right of the above photo  is the kind of lens used as an eyepiece in a Galilean telescope. Look at the eye in the photo notice how much smaller the eye and face look through that eyepiece lens. Now Galileo found with measurements that the telescope becomes more powerful and makes distant things look bigger by selecting a lens for the eyepieces that makes things look smaller, " Smaller?" It doesn't make common sense that you would use a lens that makes things look smaller to get a telescope to make things look bigger. . Lets go through that once more if we used a lens that made the eye looks even smaller than the one in the photo the telescope that would make things through the telescope look even bigger. "Smaller is bigger" Hmmmmmmmmm? .

2 nd. observation of the magic of lenses: . The lens on your left is the kind of lens used as an objective. It goes on the far end of the telescope gathering the light from the object and sends it to the eyepiece. Galileo found from his measurements that the weaker its magnifying power is (as long its greater than 1) the stronger the telescope "Weaker is stronger" Where is the common sense of that? Again note the lens on the left in the above picture makes the eye look bigger Galileo found that that was not good. One needs to pick a lens for the objective that would hardly change the size of the eye when held close to the eye to the make things in the distance really big. Low power lens makes hi power telescope. The focal length of the objective on this telescope below was 60 foot the lens was very weak but made objects come in very big? Where is the common sense in that. But it works see photo below.


3rd observation of the magic of lenses: Looking through the telescope from the objective end through the eyepiece, everything looks smaller rather than bigger. That certainly not something anyone using common sense would have guessed. Could it be that Galileo's critics were and still are  looking through the wrong end of the telescope and therefore couldn't and can't see what Galileo was seeing. Could it be that the critics of science today are looking through their telescopes from the wrong end?

So  in and around 1609 one of the first popularly dramatic examples of using the scientific method showed that common sense made no sense in the designing and building  the telescope nor interpreting what you saw through the telescope. Galileo decided and demonstrated that its far more productive to use this newly invented tool to design his telescope, the scientific method! The new tool he used was based on  the measurement of length mass time then with mathematics as his language he could  more reliably explain how things really work. Galileo used the scientific method to get past the magical tricks that lenses seemed to play on observer's eyes  and mind described above thus finding the better way to make a telescope.

So here we have the  1609 environment that Galileo worked in. The leaders and their followers  had little to no experience in how things in nature worked they assumed it was just common sense, accept when employing natures secrets  to  inventions of war and political control. Sounds like what still goes on to day.
But first and more important thing  to learn is how basic research scientist work, how they  get the research funds  to do their work and support themselves and family. Let us look at why Galileo his telescopes and the American military decided to spend  time and money designing and building  the Hubble and other orbiting telescopes.
Was it to explore the heavens and make new discoveries? 


The other side of the coin!
 Aren't The Galileo & The Hubble  telescopes,  Weapons  for and against  Mass Destruction?

What was the motive driving Galileo to work for the local mayor/warlord and today's scientist working  directly or indirectly for  the Military designing  high powered telescopes?  The monies were and are certainly not allocated to make new discoveries in the heavens just for the fun of doing it.  Galileo and today's scientist   struggle  to make  money to support their research. Galileo and many of today's scientist  make money  designing and making  measuring instrument for sale to further the needs for weapons of war. Just like many scientist do today directly and indirectly building up data about instrument of war heading their way. In Galileo's day it was for tracking Pirate ships   incoming ships and today the military for tracking incoming ballistic missiles . A high powered telescope  fit nicely into this category. In the problems of  developing  high powered telescopes  Galileo faced the theory of lens design which was primitive at best so  he made a few bad lenses. But so did the Hubble team "remember". An often asked  question that amateur  historian ask  is whether Galileo  designed his telescope   at all or  at best  by trial and error methods. Historians today ask question such as whether he did it in one day as some  claimed  he did?   How did  he do it? Instead of asking why he did it just as some of us today ask why are many basic research scientists doing weapons today? Could this be the question asked by the churches of 400 years ago and those of today why they are concerned about research?

How did Galileo design the optics of his telescope What were the instruments

 he used to understand and forecast the optical design.

One of the things one learns when studying Galileo  and which we certainly  learned while replicating a number of his instrument was that  he  was an astute observer and  very good experimental physicist. His math skills may not have been in the class with Kepler's  but his experimental skills were right up there with the best. There is very little in the Galileo's writings where he discusses how he designed his optics Perhaps the reason he left it unclear how he did the design work was  once he had the magic formula  it was proprietary business information and he would  not have likely  share it with others before he made some money on it. Thus he seems to  leave us in the dark in his writings, yet he gives us a hint in the rest of the instruments he designed like his compass and Micrometer, how he would have done it.

The hint was  a useful little instrument he used to track the movements of the moons of Jupiter  for several days he measured  with precision the distance of each satellite from the planet. To do this  Galileo  used a device he was supposed to have  invented known as a micrometer for the job. He was also knowledgeable in the development of  non linear scale and graphing as shown by his compass....Sector in modern terms.    The authors, experimental scientist themselves, suggest that Galileo had already  invented this device  or something close to it  before he started to design his telescopes. He used it to determine the laws of  optics for developing the  relationship of  the eyepiece and objective focal lengths to the magnification of his telescope. We have done it in our labs and demonstrated that  it would  have taken less the a few hours when  the lenses were available. 


Brief description of the use of the micrometer concepts in measuring the power of a telescope-

One of a number of  examples of  how Galilee would most likely have done it  is to  set up an optical bench  and using a variation of his micrometer and the knowledge of creating non linear scales he would have measured and studied  the magnification of mockup  telescopes using a  series of lens sets that would have been available at an optician eye glass shop. He could have used  a white scale  fixed up at a  distance and a sliding mark placed on it.  The telescope would be  focused on the scale and the latter is observed with one eye through the telescope and with the other eye direct.  The two images superimpose.  The mark is then moved along the scale until the image of the part cut off by it, as seen through the telescope, is equal in length to the whole scale as seen direct.  The magnification is then obtained by dividing the length of the whole scale by the length of the part cut off.
He would have investigated the variation magnification using a variety focal length   for the objectives using  a fixed eyepiece giving him the linear relationship between focal length and magnification.  Then he would have fixed the objective at a given focal and studied the affect of the magnification of the telescope  versus the eyepiece focal length which was the reciprocal. He  most likely would have  plotted the results of the combination of a reasonable number of lens to get a get a curve or set of curves that could be extrapolated to give one the direction of how to build a high powered telescope. You can do it your self by holding pairs of lenses up and looking  thru them you can see the object and the image superimposed and pretty well judge the magnification as you change the  focal  length of the lenses.

An example of  the business of science versus business of engineering.

 Below we debate the question of Galileo's choice  of a negative eyepiece  rather than positive one. It is important  to look at the design from a product development point  view. Here Galileo was acting as an entrepreneur  rather than as a  scientist. For one thing as a scientist he needed to make money. Scientist didn't  make much money then and they don't make much  now.  The engineer/product designer has  to take different things in to account than a scientist. He has to note  the nature of the customer his level of sophistication and  how he is going to use the product, the  cost of the product and how easy it is to use the product. All this compromises the design of the product. The telescope in this case. for those who find fault in Galileo design  one example namely using a negative eyepiece with its narrow field of view versus and  up right image versus using a  positive eyepiece with it much wider field of view and upside down image. we recommend they  review their opinion from this new perspective. Its important to know the difference and not confuse their different roles in our life which happens allot today.

One thing of interest in his design was his choice of a negative lens as an eyepiece. it has a smaller  field of view instead of a positive lens . Some  biographers have suggested that Galileo never bothered to look at a positive lens as an eyepiece. We suggest otherwise. When he did his experimenting there were a lot more short focal length positive lenses around than negative ones. They would have been used as hand magnifiers,  on a desk tops, or in ones pocket. They would be a lot cheaper than a pair of eyeglasses with matched lenses.

Although the positive lens for the same magnification had a wider field of view the image was upside down. As an entrepreneur as well  as a physicist he was really designing these telescope for none technical customers  who were going to use them  for terrestrial use only. They also had to be simple to build.  Erecting eyepieces require a minimum of  two lenses  and were  much more complex to design and build .There was  also a practical need for short telescopes which the  negative lens did for them.  Galileo had to go out of his way the use the negative lens only and we have to believe that he chose the lens type that gave an upright image and sacrificed the better field of view.  Galileo ground and polished the necessary lenses tested his results and had his high powered telescope in comparatively short period of time.

Galileo was acting as a scientist when he turned it up to the sky and stumbled onto  discoveries of a life time for at least a few weeks he was  gathering data as fast as he could and he would have been in a wild race  to gather this data  before some one else did (he new that he wasn't going to be the only the only scientist looking up there). Probably he wasn't thinking much about a new telescope design. He was also interested in getting a new job.


Which method do you prefer  measurements or common sense?

Additional answers to the question why did it take so long to invent the higher powered telescope. There are at least three more reasons.

Things that contributed to the delay, besides the overuse of common sense.

  • 1 st, there literally were no lenses made with long focal lengths, one meter or longer "a requirement for making a high powered telescope," This shortage was simply because there was so little magnification that they were not needed as eyeglasses, the principle market for lenses.

  • 2 nd. there was not much of a call for a device that would bring thing far away closer. Galileo became interested because of the military need. He was already working on a calculating device for gunnery calculations. Galileo appreciated the need of the mayor of Venice to detect pirate ships coming to attack before they got there, or the businessmen getting early information on the arrival of an inbound cargo ship. This was one of the finer point Marconi used in selling his radio

  •  It was only the beginning of the rapid growth of the scientific method, a method that made it possible to get realistic answers to questions about how sophisticated things work. A method that has raised the quality of life where ever it is used.

    Today, unfortunately, its taken to much for granted.

  • 3rd     and perhaps the most important observation  of the magic of lenses: Looking through the telescope from the objective end through the eyepiece, everything looks smaller rather than bigger. That certainly not something anyone using common sense would have guessed. Could it be that Galileo's critics were and still are  looking through the wrong end of the telescope and therefore couldn't and can't see what Galileo was seeing. Could it be that the critics of science today are looking through their telescopes from the wrong end? Of courses some critics would remind us that if one replaces the negative eyepiece lens with a powerful positive eyepiece it turns out that Galileo's telescope is turned into a microscope. Galileo did that also. Galileo's Microscope.

    This contemporary line of common sense reasoning versus using the scientific method was. and still is, so strongly imbedded in some people on an international scale that it could be labeled as a syndrome.  The  authors are moved to call it the "Galilean Syndrome". Fortunately there is a cure on the horizon, namely, Education: education of our leaders, its citizens, and most importantly, ourselves.

    "Special side note- Some leaders felt so strongly about the value of common sense in Galileo's day that they thoughtfully decided that people of note, who disagreed with the results of common sense were misleading the rest of the world and they should be disposed of by Burning them alive at the stake. This  would solve two problems at the same time; one, eliminate the messenger, two, send a strong warning to any predisposed follower of the same path.


    A short review; What motivated Galileo to use his skills as an experimental physicist to design a high powered telescope and how did he use really use the telescopes for official purposes?

    The thing that motivated Galileo was not just to discover, new truths, but to make a living which he did in part by designing and building weapons of war such as calculating devices for aiming artillery pieces at the enemy and for commercial use by being first to see a freighter coming into port. When he heard of low power telescopes he reasoned that if he could design and build  powerful telescopes  he would  be able sell them  as  spyglasses to those who needed to could keep track of their enemies movements from a safe distance. Galileo did just that and traded his rights to his invention for an increase in salary and a tenured position at the school he was teaching. To be sure there were other telescope designers who were using common sense for their designs and occasionally stumbled into an improvement. As a testimonial to Galileo's skills as an experimental physicist he decide to look beyond the common sense approach and turned to systematic measurements of the parameters such as the curve and focal length of the lenses on the power of the telescope. He of course found that the lens selection did not always make common sense, But he did find a model with its set of dimensional rules that allowed him to make the most powerful telescope of the day which he needed for his raise.


    The bottom line, The image, Click toTake a look

    Very few people today have ever seen the image as Galileo would have seen it looking through his telescope. Here is your

    opportunity click on the thumbnail below to see some of the magic of the optics for your self. It is vastly different than the cropped images processed and prepared for the web or popular magazine on astronomy.

    .By the way modern

    measurements of the lens Galileo made and used, are reported in the modern literature to be of good quality.




    The "how" of building them

    Building a Museum Grade Replica

    Faithful replication has its challenges especially if one attempts to reproduce these telescope as they would have looked in their original form. some 400 years ago Not surprisingly one can not use the originals as the only reference source. They have had a moving legacy of strains and stresses ranging from normal aging, neglect, untold restorations, and mistakes in its inventorial process. Creditable museum grade replication requires much time consuming research in sorting this out. In the end, just as basic research in science goes, it will never be completely sorted out it is always a work in progress. Still the bottom line is that it is worth the effort because these telescopes says so much about how science really works and since There Are Really No Words Powerful Enough To Express The Importance Of Basic Scientific Research To Our Past, Present, And Future they can show it by example. The internationally famous Galilean telescopes are important symbols , of an epic of the trials and tribulations of basic scientific research in 1600 and today, These telescopes help us by example to get a connection to our future by looking into their past.

    Our goal has been to reproduce every part of Galileo's leather telescope inside and out  to within a few percent of the original, which to our knowledge had not been done to date. We reviewed, critiqued  and  cross checked  data we found in the literature finding  a number of errors in the quoted physical parameters of the original and museum replicas. We augmented these data with our measurements .  For the few cases where not enough data was available or where our choices differed with the literature, our replica allows for easy reversibility for these parameters when/if more data becomes available.

    As might be expected one finds that even the very best reference material including the item being replicated carry errors some of which can be reborn (if there is not sufficient research) every time a new paper or replica is issued. We grew to really understand this first hand in our attempt and we still have a few unanswered question, which may never be answered for example the eyepiece (ocular).

    The authors have spent hundreds of hours of research in both the literature and the laboratory to sort this out and to make the most accurate replica possible.

    If each of us could study Galileo dramatic story with one of these telescopes at hand we could reflect and appreciate more fully the value and needs of basic scientific research. Unfortunately few of us will ever get to visit the originals in Florence Italy let alone touch them. The next best is to substitute a precise replica of the telescope. The more precise it and Galileo's story is the greater our connection to the epic.

     Therefore our primary motivation has been to have the visitor to the replica of the telescope feel confident that what he or she is looking at, or is lucky enough to use , is an exact as possible copy of the original instrument , that it works the same, looks the same, feels the same, is the same, inside and out, as if Galileo had produce a twin. 

    References and a caution about Galileo's story; It is very hard to get a clear picture of the history of anything even a scientific subject such as Galileo and his telescopes. We strongly recommend getting the information as close to the source as possible such as (Galileo's writings) and to be careful of papers analyzing history for you . Choose a source loaded with lots of reliable references. From our experience the following sites are reliable professional sources of information, and While not totally free of errors these sites for the most part are manned by professional historians. We have also listed a few that were relevant to our needs. see our appendix .

    A longer review of the topics above A debate to give it or not to give it an old look that is the question Words from the play HAMLET? When Prince Hamlet considers suicide?


    Below is much of the detail for constructing these replicas sprinkled with the philosophy of our efforts to make them as close to the original as possible.
    1,Click here to see a video of one of Galileo's original telescopes in its cabinet

    2,Click hear to see a short video of the results of our efforts.

    We have built two of these beautiful instruments. One went on exhibit at Griffith Observatory October 2006. The other served as a prototype and backup during the building process. Each has nearly 100 parts and over 400 hot gilded stampings. It has taken upwards 1200 man hours of research and shop time to build them. Tolerances are within approximately 1.5 % of the original, most times closer both inside and outside. In this web page we go into a detail description of  the internal, external parts of this internationally  famous telescope showing a number surprising building details not generally known to average  Galilean buff.

    Many people have helped us in this job. The authors thank all of those who helped with donations of time, material, advice, encouragement and patience. You all have done a great job. Your help will be a lasting contribution to our understanding of the
    Pernicious Galilean Syndrome.


    1.  Replicas and accurate replicas
    2. Visit the IMSS Home of the Galileo's Telescopes with a short video
    3. Galileo's telescope construction
    4. Art work and making the tools
    5. Hot stamping the Gold Deco's
    6. Len grinding, polishing & testing
    7. Done Finished Telescopes
    8. Appendix random thoughts and references
    9. Visit our web other site where we are building Galileo's IMSS number( "2" see our ref 2a) telescope for Adler Planetarium in Chicago
    10. Visit our site Antiques of Science and Technology
       Click on the pictures with the colored boarders to get larger views.
      Send comments to

    One of the authors on his knees not worshiping but
    taking pictures and measurements of Galileo
    to make better replicas for us to enjoy.
    To help motivate us to learn more about the
    historical trials and tribulations, then and now,
    and doing basic research.

    The telescope will be on display at the Griffith Observatory around October of this year for the public to enjoy and think about. The authors hope you do both and enjoy both.

    A Pictorial Summary with part of the Galileo telescope team at various stages of replication

    The seeds of Galileo's presentation telescope, wood staves. They are used in all the tubular construction.

    Lens grinding and polishing The machinery is modern but the motions of tool and the lens is 1600

    The overall view of the bare body and sliding lens holders showing the novel construction.

    Leather had been added but not been aged to darken it and the Gold deco embossing was next.
    We were making two telescopes one as a backup.

    Rhoda with the plate of hot stamps decorations, 21 of them. At this point each deco had to be precisely cut from the Magnesium plate and mounted on handles. We  made three versions of these dies to get them right.

    Some of the hot stamps needed for the gold embossed decorations--- The objective end of the telescope, note
    resin composite construction.-- Galileo supervising the work. from the cover of a fine book on Galileo and his telescopes "The Sidereal Messenger by A professional Historian Albert Van Helden"

    Hot stamping (gilding) the body of the telescope using a self centering "T" square jig we put together to help guide the location of the die. The stamping is still hand done maintaining irregularity seen on the original. There more details of this jig shown below.


    The stamping operation

    To start video press start arrow twice wait a feww seconds to play

    A 2 minute unedited video of the stamping operation. Rhoda is using an enlarged photograph, one of dozens of the original telescope we took along with measurements at the IMSS in Florence Italy, to help guide this work. To left is a hot plate to heat the die. To its right is a water soaked pad to aid in setting its temperature. One can see the placement of the gold foil under the "T" square. and the embossing process. The telescope is indexed by hand to next location and the process is repeated There are over 400 impressions.
    We have been asked why not speed up this operation by any one of a dozen ways saving time and money. We considered most of them but in the end the most visible thing about the telescope, these decoration, in our view, would have been seriously compromised for museum use .

    A visit to the home of one of the Original "Galileo" Telescopes and a brief outline of some of the issues of making an accurate replica for museum display.
    See More Detail of the trip to the IMSS Museum, Florence & Venice

    Dr. Strano IMSS who was a rich source of technical information & Jim in front of the case displaying two Galilean telescopes that were built within the year of his great discoveries, the moons of Jupiter and the craters and mountains of our Moon.

    The objective end of the famous Number 2 telescope with its beautiful art work.


    Photo by Jim & Rhoda Morris taken at the set of The TV special Brilliant Minds

    Garnering the measurements


    A trip to IMSS Florence Italy to take pictures, get pictures, and measurements of the original. There is very good data in the literature on the optical performance the Galileo telescopes at the IMSS in Florence Italy. However there was ambiguity in the literature available to us on the mechanical and decorative aspects of the telescope. This made it necessary and worth a visit to the original instruments to measure and photograph it. The trip was very valuable. It helped clear up the uncertainties making it possible to produce a replica worthy of exhibit in the new Griffith Observatory Museum.

    We were concerned about the

  • dimensions of the various components

  • specific construction details

  • materials used, and

  • exact nature of the gilded decorations

    2.General results of the trip
    Rhoda and I cannot thank the staff of the IMSS and Griffith enough in helping to make the visit both productive and a pleasant experience. This wonderful museum displays important instruments of science which are also beautiful works of art. It is a must see on a trip to Italy.
    We visited the telescope on three days. The staff were very helpful, professional, and kind. We had fruitful technical discussions, made critical measurements, and took photographs which enables us to make a significantly more accurate reproduction of this famous telescope .

    The excellent photographs taken before and after a recent restoration of the scope are a kin to a break through letting one see the essential details of the rarely viewed insides of the telescope thus giving us the intricacies of the construction techniques used. These data are indispensable for making a replica, which we are doing, that is worthy of the Griffith Observatory. They are also useful to study the building skills and practices available to Galileo, his associates and assistances in their engineering and scientific work. The construction is unique and far ahead of its time. It probably has a lot to do with the telescope surviving to this century in as good a mechanical condition that it has. It uses a technique that show the advanced understanding of composite construction lending itself to mass production that has a strength to weight ratio the envy of builders to day. Last but not least it has good mechanical stability resisting the normal warping of the wooden parts. Reference 1

    Below are the IMSS staff that were so helpful to Jim & Rhoda on the visit to the Galileo Telescopes and his Finger.

    Franca Principe IMSS who took the excellent photographs before and after the recent restoration.

    Karen Tomashavsky IMSS who helped in so many ways coordinating our visit and giving a wonderful tour of the exhibits.

    Sabina Bernacchini IMSS who helped make available and processed the many request for the photography.


    Replica of Galileo's Telescope for Griffith Observatory
    Picture taken from Friends of the Observatory brochure Tel 818 846 3686

    Galileo's Telescope Gathering the size, method of construction, and the decoration data.

    3.The tools and methods we took with and used for taking our measurements and photos during our visit.

    We built up a portable measurement stand using a modified short focus telescope with cross hairs and a 4 foot scale to measure the dimensions of the telescope from outside of the case. This device had a reading precision of 1/5 mm. but due to the distortion of the roundness of Galileo scope the diameter measurements had less accuracy. We confirmed the outside measurements of the lens holders but found a meaningful difference, in the telescope overall length as reported in the Catalogue of Early Telescopes by A. Van Helden . The significance of this difference is discussed in the "Optics" section below.

    Substituting a camera for the telescope, we took close up photos along the telescope body, but for the most part we took free hand shots. We used two 35 mm film cameras with macro lenses and a digital camera capable of a spatial resolution of 2592 X 1944 pixels to record the gold and decorative art and make relative size measurements. We focused at two distances and several exposure levels. . We did not have visible access to the back or bottom of the scope.

    The video.below shows the original telescopes in their case at IMSS  along with one of our setups for taking the overall dimensions and views we had of the telescope while we were taking our measurements and photos.

    Click twice on the play button below to see the streaming video.

    Studying Galileo's Telescope in detail disclosed a unique resin composite construction. It is not made of cardboard and paper as is often reported in the literature This discovery gave us the opportunity to study the methods and philosophy of construction available to and generated by Galileo, his associates, and assistants in their scientific and engineering work. This work has raised some interesting academic and replica questions. 1.Was it designed for "mass production" by non skilled labors? 2, was the eyepiece lens the only part replace or was the lens holder also changed? Studying the original in some detail has helped us in our mission to construct a much more faithful reproduction inside and out of this famous Galileo telescope for the Griffith Observatory.

    4.Construction Details of Galileo's Telescope Tube and Lens Holders. New data, choice of cutting strips, and importance of keeping them in order. Tests of hide glue gives good filling characteristics and has adequate strength.
    s mentioned earlier we were very fortunate in addition to our measurements and photographs of this beautiful Galilean telescope to also have access to excellent pictures taken before and after a recent restoration. These pictures showed that the internal construction of the telescope is not of cardboard and paper but of wood and in a most novel way. This opened to us a very rare opportunity of making a very fine replica in the most complete and accurate detail even to the interior. This accuracy of course helps to show the inventiveness and creativity of how scientist worked in 1600. It shows along with its history the on going issues and struggle of the basic research scientist trying to get support for their research and acceptance of its results. This telescope and its history shows ----Not only the technical aspects of science ---- but the politics of funding for basic research work, of the struggles in convincing others to see the world more clearly from a scientific measurement point of view. This telescope served as a political tool as well as a discovery tool. It was designed to impress people not of science but of power and wealth by the richness of its decorative appearance. it was also preformed well, 20 power, to show them his discoveries.

    The data we collected were vital in making a truly faithful replication of both inside and the outside of this remarkable telescope. Many if not all replicas of this telescope in the past have not had this opportunity or not felt it worth while to go beyond the use of cardboard, plastic or metal tubes and turned solid wood lens holders none of which were used in the original instrument. Some have had to replicate the telescopes without accurate data thus included in some cases serious errors in their replication. We believe that this is unfortunate and scales down the broadness and richness of what is to be learned from this telescope. We feel, perhaps unfairly, that the lack of detail and authenticity only increases the myopic view for some of what science is all about.

    Below we show you the detail of the very elegant mode of construction and the amount of detailed work that was required to make it.*

  • Figure 1 One end of the tube of the telescope Photo courtesy IMSS

    Figure 2 One of the lens holder Before Restoration Photo courtesy IMSS


    Comments about the construction.
    From a casual point of view the construction technique is novel to say the least, to some it looks like a poor design. See figure 3.Barrel like tube construction requires the edges of the staves to be chamfered butting up to each other if it is to have radial strength . Without careful attention to these gaps it weakens the radial strength of the tube and will collapse on its self See in figure 4.

    All these issues disappear when one notes that the builder used a resin glue, which had to be liberally applied layer by layer soaking into all the cracks and filling all the gaps. This is a method that we today call
    a resin composite construction. It consists of bonding all of the materials and parts of the telescope together with a resin. The resulting structure has physical characteristics superior to the components by themselves. Ref. 1

    Sticking the sticks together.

    Figure 3 shows how the tubes were built It was a construction that was used on both the telescope tube and the lens holders, the latter having upwards 2 to 5 layers until the tube were the right size and strength.
    We built a small section using this construction technique to demonstrate how it might be made and to test its strengths and weakness. for the replica.
    It's a strake-style construction comprised of a number of strips of wood fixed on a thin flexible backing and rolled into a tube. It's easy to build but note the gaps on the outside. The tube strength depends markedly on the treatment of these gaps. Without a filler between them the junctions would collapse on themselves with very little pressure . We show this in figure 4. 

    Figure 4

    The telescopes strength--
    In preparing the first layer for the second, resin glue is put on the outer surface of the 1st. thus fills its gaps. Preparing the second surface for the third fills the second layer gaps, and so on to the final step. At this point one has saturated the whole tube layer by layer generating a resin composite construction which is light and strong using a minimum of simple tools. A process that lends its self to mass production.


    Figure 4A, Simple construction steps which do not require a lathe. Note the tube can be squished as in 4C, a" feature" making the joint gluing easier. It only requires a simple square not cylindrical mandrel.

    • Strips of wood are cut from a single sheet. These cuts don't have to made with precision and in fact are rarely straight when done by hand. But when the pieces are kept in sequence the gaps between them maintain a uniform width. See inset photo in A.
    • A, Strips of wood glued to backing
    • B, Strips bent in to tube form
    • C, Tube is clamped while glue is setting
    • D, Tube ready for next layer

    Figure 5 Second layer
     A test section showing the novel construction used in the number 2 Galilean Telescope. Today we call this a resin composite construction. Its light, strong and cheap. It resist a 100 lbs crushing force.

    Visit to Adler Planetarium The trip to study the Italian Cipriani Replica at the Adler planetarium Chicago was a very valuable visit and the Adler staff was very helpful. We gathered new data, 50 digital images and 33 35 mm color negative along with numerous measurements of the telescope. We also got very important data on the telescoping lens holders.

    Below are the Adler Planetarium staff that were so helpful to Jim on the visit to the Cipriani replica of Galileo's # 1 & #2 telescopes in Chicago Ill . Their professional help and patience helped significantly to our making the replication of the orginal Galileo telescopes more precise than has been done before. _Thank you again Jim & Rhoda Morris


    Michelle Nichols,
     Master Educator Adler Planetarium & Astronomy Museum

    The beautiful Cipriani replica of Galileo's # 1 telescope being treated with the care and attention it deserves.

    Devon L. Pyle-Vowles
    Collections Manager Adler Planetarium & Astronomy Museum


    Important issues comparing the original Galileo with the Adler Cipriani replica telescope
    Deciding on sliding tubes for the lens  Both the Cipriani replica  telescopes have sliding tubes carrying both the eyepiece and objective that slip into the main telescope body.
    The question is did the original have them too? This was not completely resolved with our visit to IMSS. From the literature we found  extra decorated space between the objective housing and the end of the barrel. This  appears in figure 9 below, suggests that at least there was a sliding lens holder for the objective which could have been used  for extending it out for longer  focal length objectives.  Using this objective adjustable feature for focusing would have been troublesome it is too far to reach. Therefore an adjustment also at the eyepiece end would also have been sensible. essentially The photos of the original telescope during restoration suggests that the protruding staves were part of the sliding mechanism at both ends and not simple cardboard tubes as has been suggested. It appears that the tubular stave construction was used throughout .  Also the 1704 inventory listed the telescope as coming in two pieces for lengthening it. We still wonder about the little Marble paper covered eyepiece holder which would make three length changing elements even though it has very little adjustment, perhaps 8 or so millimeters hardly the 7 cm. needed to focus on objects 30 meters away. We believe that there is enough circumstantial evidence suggesting that the Florence telescope has these telescoping lens sections as well, but they are stuck inside the telescope IMSS photos show the staves sticking out from ends of the main tube.  We therefore include telescoping tubes  in our  replica.

    IMSS photos of the staves sticking out of the body of original telescope gave us a good measurement for the outer diameter of the sliding tubes but not their length

    The length of the objective tube we were able to establish to an accuracy of about 1 centimeter. To get this length we used our measurements of the expanded portion of the main telescope tube at the objective end  which is expanded  down the main  barrel to accommodate  the sliding tube.

     For the eyepiece tube we chose to use  the length of 27 cm  as was  used in Cipriani replica at the Adler Planetarium . If  Information surfaces to the contrary  it can be cut back to 12 cm where the decorations on this tube start.

    We also  looked into the information to be gained for an estimate of sliding tube dimensions  from the Cipriani replicas. We looked into two of his replicas one at the Science Museum south Kensington London reported by  Baxandall in our  ref 1.   The second from our  measurements of a Cipriani replica at Alders Planetarium

    Baxandall  in his drawings do not agree with each other to within 10%  nor do they replicate the outer dimensions of the original where the diameters are different as much as 10%  which is a factor of 10 greater than our goal for accuracy.

    Also strangely the Cipriani telescope does not have a red marble paper covered eyepiece which would have been altogether out of stile with the rest of the original instrument but has a decorated disk framing the eyepiece down in the container similar to the objective. A detailed examination of his replicas shows a number of strong differences between them and the orginal ranging from dimensional differences to art work differences It almost like Cipriani tried to incorporate improvements and changes to make it easier to build.

    We also took detailed photos of the decorations covering the telescoping sections of the Adler instrument. They are a combinations of the deco's on the out side but patterned and scaled differently. We did not incorporate any of Cipriani inconsistencies in dimensions and  We chose not to make them out of cardboard as Baxandall reports that Cipriani did for the replica for the science museum London but stayed with  the stave construction which is consistent with the rest of the original telescope.

    The visit Adler to get detailed pictures and measurement of the art deco on their number 2 replica was also very valuable. Although there are some issues in scaling and details in shape of the Cipriani instrument that are not true to the original telescope we were able to use then to get a better prospective of the finer detail always referring back to the original to make the final decision for this project.

    Figure 9 Image from The Cambridge Illustrated History of Astronomy pg 123


    The Telescope Optics  This section presents the  details and a discussion of the optics that are presently in the Galileo IMSS 2428 telescope and  the optics we used in replicating this telescope.

    Below  is a schematic, not to scale, for a visual aid to help our understanding of what the eyepiece and objective physically look like and an optical ray diagram of a Galilean type telescope The path of the rays of light through the lens was reproduced from a 1860 text on Natural Philosophy.

    Click Here Technical uncertainties in the optics of Galileo's telescopes

    Photo by Jim & Rhoda Morris taken for The TV special Brilliant Minds

    Note that both lenses are double convex or double concave in this 1860 drawing. We have found this to be  true for drawings from at least 1800 up to today. See Galileo-Telescope-Anomalies-optics This is not at all what Galileo had a mix  in his telescopex.  He had both plano concave and plano convex lenses. Is this important? Absolutely.  This is a good example of a technical error in reporting on Galileo's choice of the lenses which are the telescope. Further it is an  error in descriptions  on one of the most  historically famous, international  telescopes. An error that has stayed with us for hundreds of years replicating its self over and over again..

    Neglected errors of this sort is not good science or reporting of science. It distort our view of what Galileo and the early lens makers knew about optics in the1600's and the issues of  who invented what and when. From the professional literature if true Galileo did not invent the telescope but  did invent one with higher power using lenses with one of the surfaces of each lens with such little curve in it that one can say that it was flat. He also used a negative lens as the eyepiece.  The use of double curved lenses and more than two lenses are other inventions and most likely other inventers. 

    Galileo's  telescopes are  extremely important symbols of what basic research is really about.
     No Words are  Powerful Enough To Express The Importance Of Basic Scientific Research so we start off this section of optics with an example of the importance of accuracy in our choice of lenses. When we look at  Galileo and through his telescope and use him and his telescopes as symbols of what science is all about here is example of distortions of science that misleads us about science.

    There is no room for sloppiness in science or reporting about science.   The most essential tool of scientific research is "accuracy" in the treatment and presentation of data, data from which we development conclusions. When the scientific world present (publishes) their data publicly or in private communications  More important than the data itself is  the qualification of the data. How accurate is it and how was it taken etc.? Using this tool is one of the reason science has been so successful.  Each piece of data lays the  ground work for next collection of data etc.etc..

    Our choice of lenses; One of the many departures often made in building replicas of Galileo telescope is to compromise in the focal lengths of the lenses. Galileo's objective of the #IMSS 2428 telescope has been reported to be 98 cm.or 95.6 cm. requiring nonstandard lengths therefore costing hundreds of dollars compared with the much cheaper standard focal length of one diopter or 100 cm. If one uses the cheaper lens this unfortunately  leads to a domino affect of compromise. It changes the over all length of the telescope by almost an inch which in turn alters the location of the gilt decorations on the body of the telescope and it also changes the optical power. Where does it stop? If we use the powerful story of the Galileo telescopes to teach people about how science works. how can our audience trust us if we don't even use the first basic rule of science, accurate repeatable testable measurements of time length and mass in building this symbolic Telescope?

    Our finial choice for the lenses and why. Conflict in the modern measurements of the exiting lenses at IMSS

    The objective: see our references
    We have chosen to  use the 1992 Greco etal.  ref-----980mm. f.l. measurements rather than the 1923 Ronchi's etal.  956mm focal length for the objective. There are 3 rational for this decision.

    1st The over all length of the body of the telescope is too long  to focus the telescope at infinity with an eyepiece of 5 cm focal length. The eyepiece would have to have a considerably shorter focal length resulting in powers greater than 20.(look further on in our web site at how to determine the over all length)

    2nd   If one takes The Refractive index of Ronchi's calculation and his measured radius of curvature one  calculates the focal length to be 980mm..rather than 956mm. An inconsistency within the data is suggested.

    3 Greco etal. must have known of the difference of his and  Ronchi's measurements because he references Ronchi therefore we feel that it can be safely  assume he would have checked and  rechecked his data to be sure his measurements were correct.

    The Eyepiece.
    This lens is not the original so we have to make an independent decision. based on measurement and experience. and our effort to reproduce it as it was originally. There is a fair agreement that the original eyepiece has been misplaced. so    We  We have chosen to use a plano concave eyepiece  instead of  the biconcave lens as is  presently used in the current telescope but use the same focal length based on our arguments of telescope length and our measurements of it described earlier..

    We use three rational for this decision.

    1st The other longer telescope IMSS 2427 uses a plano convex lens.

    2nd  there a fair consensus that Galileo made  a number of his own lenses so it  was simpler and faster for Galileo to make a  plano-concave lens.  For the most part he only had to grind and finish one rather two surfaces.  Grinding is faster than polishing and he would have only one surface to polish..

    3rd  There are significantly fewer errors going this way, Errors like getting the two radii lined up etc.  which In our opinion Galileo would have certainly known about from his experiments. never the less  if our choice has been wrong its simple to change the lenses.



    Overall length of the telescope is determined by the optics There is an Inconsistency in the length of the IMSS #2428 telescope. It is reported that the length of the telescope is the same as the focal length of the objective. This does not leave room for the eyepiece when focused on distant objects.

    Total length of a telescope focused for infinity = Focal length objective + Focal length eyepiece + lens holder over hang .

    NOTE the overall length will vary depending how far the lens have been extended for focusing. It appears that both the object and the eyepiece can be used to extend or reduce the optical length for focusing. (see figure 9) this maybe about 10 cm plus 20 cm for both.
    The present telescope at IMSS has an objective that is plano convex with a focal length of 980 mm and a diameter of 37mm. The eyepiece is a biconcave with a focal length of -47.5mm and a diameter of 22mm.

    The optical length of the telescope for an object at infinity would be the sum of the focal lengths, namely 

    (980 -47.5) = 932.5 mm. add 12 mm for the over hang in the holder. This gives calculated figure for the over all length of the IMSS telescope closed of 944.5 mm. We have measured the scope at IMSS, with the apparatus described above,  plus a video showing the operation,, to be 945 + or - 5mm which depends on the position of the eyepiece and objective tube. It looked to be closed when we measured it.

     Our best guess at presents' that it can open 20 cm more giving a length of 1165mm. for focusing on nearby objects.

    The catalog of early telescopes by Alert Van Helden, page 30 lists the telescope's overall length as 980 mm., which is off by about 35 mm. or nearly 1 3/8 of an inch different. according to our measurements

    The objective has a focal length of 980 mm lens which is not a standard production item and therefore an expensive piece to purchase from out side sources. In stead we purchased four 1000mm fl. lenses and shortened them to the to 980mm fl . .
    We tested the process with plane glass blanks and found that we can make changes in the shape at a rate acceptable to changing the focal length of our 1000 mm. lenses to 980 mm. See photos below

    General details of the equipment assembled to shorten the 1000 mm focal length lens to 980 mm.
    We have tested the process with plane glass blanks and found that we can make changes in the shape at a rate acceptable to changing the focal length of our 1000 mm. lenses to 980 mm. See photos below

    Here is a web site that explains how the lens testing method that we are using works

    Optical diagram of lens testing apparatus

    Close up of the lens holder and optical flat

    We tested the polishing machine using a 2 inch diameter 1/8" thick plane glass blank. with 4 minutes of polishing we took off about 46.4 millionths of an inch and converted it to a convex surface. The photo above shows the interferogram of our glass blank with the interference lines use to get this measurement. It's going in the right direction with reasonable speed. All we have to do is get good spherical surface and not overshoot the focal length of 980 mm.

    close up of the light source and the knife edge

    Lens Grinding/Polishing Machine

    Lens polishing /grinding machine that we've put together for this project.
     We are going to use it in an attempt to polish down the focal length of the 1000mm lenses to 980 mm.

    5. The all important art work
    This telescope was not destined to go to a  colleague  but to a customer of high rank and station and is an important part of the Galileo story, It is a symbol of his marketing and entrepreneurship. While there is no strong evidence that Galileo would have done the gold leather stamping himself his the choice of the artisan was no less critical to him then the rest of the detail of producing this telescope, beauty and flattery had to be part of his skill set. So as it is  today. One stopping to visit and admire  this telescope deserves no less than to be  treated as one of high rank and station if we are to gain their support  of basic scientific research.

    Developing the art work from photos contains many complex issues. It has been a slow and exacting process extracting the shape and detail of each of the deco elements from our high resolution photos which show each dent, scratch, warp and hand made irregularity. Rhoda and I have spent hundreds of pleasant hours deciphering and unfolded the detail to get as close a match to the orginal hot stamp as possible. the outcome of this work are more than 20 hot die.

    Below is a fairly detailed discussion of the methods we have used to select build up, and clean up, the photo images for the art work we have been using to make the black on white figures to engrave the hot stamps that are used to make the gold foil impression on the leather of the telescope. Details like the black and white drawings also have to take into account the impression process leaves a figure that is somewhat different than the engraving on the stamp. p.s. (Even the description of how it is done is long and tedious. But the results have been satisfying). To make a faithful replication of the gold art work on the telescope one needs a lot of high resolution photos of the telescope showing this detail.( our visits to Florence and Chicago produced them and, the wonderful here-to unnoticed structural features of the telescope). Even so it takes some time to get a feeling for what the original figure looks like because each component although made with the same stamp experiences a different history of application and ware and tear.

    More General Background Information About the Art Work Decorations are applied with a "heated" stamp pressed on a piece of treated gold foil laid on the surface of the leather. Up to 20 or so pounds of pressure is applied to the leather embossing the figure and gluing a gold film to the inside of the impression . The stamps we are having made are out of Magnesium plate by printed circuit board type of technology using a photo resist coating on the magnesium. We supply the black on white pattern for the figure to be etched on the medal to the vender who makes a photo negative See figures 6A and 6 B. these are used is to exposed the image on the plate. The unwanted portions are etched away leaving a stamp which is cut away from the plate and then mounted on a handle.


    6A & 7A Below are photos of the original telescope at IMSS and a replica displayed in the Adler planetarium Chicago Ill. Florence, Italy c 1930. We have modified the photos of the replica substantially to make the decorations stand out more clearly. This has altered the colors from their true appearance. One can see substantial differences between the two scopes in the deco details as well as the eyepiece which does not show the small sliding focus lens holder.

    Figure 6, Above the objective end of the original telescope

    Figure 6A replica at the Adler planetarium. We have altered the colors to show more contrast in the decorations.

    Objective end; Low resolution photos. There may be as many as 20 separate art components in the repeating pattern shown in the above design each requiring a separate embossing stamp. The Adler planetarium replica has clearer impressions of many of the figures but there are difference between the original in many of the details

    figure 7,Above the eyepiece end of the original Telescope

    Figure 7A, replica at the Adler planetarium. We have altered the colors to show more contrast in the decorations.

     Eyepiece end; low resolution photos. Most of the art elements are remarkably different than the objective end. The literature reports that the original eyepiece lens was lost. Was the holder lost as well or restored using different tooling. The sliding part of the eyepiece is covered with a red and green marbled paper.
    The Adler replica doesn't have a separate sliding eyepiece holder and there are strong difference in the gold decorations.


    6.An example of generating the data to make a stamp for Gold embossing the Decorations.

    Alder Replica
    First Guess at Shape of Die. Not good enough. By the way this is reported to be a dolphin.

    Original Telescope
    Even the beautiful photo below shows loss of data in the flowers on the top and one of the feet below. In this case we have had to take a parts of one image and add it to another to get the lost detail.
    there has been a loss of symmetry in the two branches because of the way that the craftsman applied the hot stamp.
    So all of the individual deco's are a composite of several photos

    With our discovery of the c 1930 Guilio Cipriani, replica at the Adler planetarium presumably made from the original number 2 in Italy we found substantial difference between the original and the Adler. But the Adler was important because of its finer detail than what is left of the original. Thus we were fortunate to obtain more detailed photos and provenance. before we committed to an order for the stamps. This has turned out to be very important to the project

    To reiterate, there are a number of reasons for the differences of the components of the decorations.

  • 1, damage to the figure, scratches or digs
  • 2, different application pressure
  • 3, different orientation by the artist applying the figure.
  • 4, previous restoration, stretching of the leather, etc.
  • 5, the selection of the particular design component

    The above black and white figure so far is a composite of the best images of the original telescope. The Adler Guilio Cipriani, replica has given us some added detail for a better replica.


    One of the tricky things about supplying the art work is that the impressions on the leather from the hot stamp are not exactly the same as the black and white art work supplied! The gold embossed images are broader and less sharp than the stamp. The deeper the stamp impression the broader the outline of the image. Obviously the impression has walls which are coated with the gold leaf. The walls are not truly vertical but slant, the slant making the image broader to the observer. The slope depends on the physical characteristics of the leather and the depth of the impression. The softer the interior and the harder the surface of the leather the shallower the slope of the walls and the broader the art work.


    The comparison above of the variations of a single component in the art work of Galileo's telescope versus  a number of die's and  a 1920's  replica by Cipriani shows how different the outcome can be. We made several sets of stamps until we were satisfied  by the tests described below. Extracting data  from the figures on the orginal to obtain a suitable reproduction is a challenge.

    Below we take you through several steps in. the process including the creation of a guide jig  for applying the stamp that would allow the natural operator randomness of placing the stamp on the leather.

    Art work on monitor is from Cipriani replica The art work on the telescope has at least 20 distinct components a few can be combined to perhaps 15 individual stamps. To save money on the project we have put about 20 figures on a single sheet of art work thus making a one step operation, producing one large plate of Magnesium full of dies which reduces the cost of put out sourcing in this step to one tenth. The photos shown below is a single piece test of the operation less the trimming of the die around the working face .

    Again Art work on monitor is from Cipriani
    The deco components are of course on a cylindrical surface and the camera records them on a flat surface distorting in a cylindrical sense the figure you are trying to replicate. The technique we developed to unfold this image distortion incorporated both mathematical and non-mathematical methods. We printed out the best estimate of the components of decos bands and fixed them to a solid wood mockup of the scope. Then took photos of our work and superimposed them, using Adobe Photoshop, on to our photos of the original. This technique gave us a very clear view of the over all comparison of the replication. It gave us at a single glance a highlighted view of the differences especially the ones that needed correction. It also clearly showed the precision of the orginal artist making the gold imposed stampings. The authors also made cylinders of each ring to use in a hot stamping jig discussed below. Last but not least the mockup can be handled roughly giving the craftsman a real time three dimensional over view a guide of the location, sequence, and arrangement that the stamps that have to be applied to the leather. This method helps us make a truly unique and precise replica.

    The plate of hot stamp dies


    • The steps to make the die are
    •  cut the die from the plate
    •  hand trim it
    •  mount it with a stub handle to attach to a the working handle.

    Figure 7A the hot stamp in the rough cut from a larger plate.

    Applying The Gold Embossing
    The next to the final step is hot stamping the gold embossed decorations. The hot stamping  was quite a challenge. There is a 60 sec video of it happening. The telescope has a number cylindrical diameters, conical sections including telescoping sections. For all of its simplicity its a complicated little beast nothing really square to use as a reference point .

    Our universal hot stamping jig. After a number of practice sessions by us and professional craftsmen it was clear that one could not get sufficient precision locating all of the deco components by hand with out the aid of a series of positioning  jigs to help locate the die . Rather than making  individual jigs we decided to design and  make a universal jig which is shown in the photos. Our hot stamping jig is designed to help the craftsman navigate through the collage of better than a four hundred impressions. This jig is essentially a self registering "T" square that indicates to the operator what part of the decoration is being worked on. The telescope lies in a "V" trough at the base of the jig. In this photo we have placed a test piece in its place and are running through a trial stamping to check the procedure. Our universal hot stamping jig is a series of  locating translational, rotational and centering devices fitted together on to a single base. It helps free up the operators hands to concentrate on the stamping process. For example the wheel C in figure 4 in the photo below carries a sample of figures to be stamped on a given band. This is used to coordinate the application of the individual impressions. It is connected to the telescope through a threaded rod .We have added self centering judicial line for the rotational orientation. It hangs on the bottom of the vertical metal 18 inch tall strip that can be seen on the right of  figure 1 .  Close up shots of most of these items are shown in the

    figure 1

    figure 2

    The telescopes is covered with leather and is in the jig to go through the gold embossing steps. The operator uses this self orienting "T" square to locate the hot s stamp.

    As out lined above there a sizeable number of discreet patterns most of them interlock with their neighbors.

    figure 3

    Its important to note that the principal role of this universal jig is to locate a starting point for one corner of each die. It is important not to acquire a machine made like appearance to the embossing. It is vital to retain all the uncertain hand variables that a skilled craftsman has and that is so clearly visible on the orginal telescope. So except for the first contact point the rest the impression has been left up to the operator which includes rotation, and variable hand pressure. 

    The cylinder is a layout guide attached to the telescope thru a threaded rod and rotates in synchronization with the scope. It carries a full scale picture of the details of each decoration band. The fiducial line aids the operator in applying the hot stamp die to the leather in the appropriate location.

    figure 4

     Finally a skilled craftsman applying the hot stamped decorations with the aid of our self orienting "T" square. The telescope is nearing completion. The final step is a slight darkening step to the leather to reach the correct color scheme of the original when it was new as described by Van Helden .

     figure 5

    Copied from WokipediA The Free Encyclopedia  
    With the loss of many of his defenders in Rome because of Dialogue Concerning the Two Chief World Systems, Galileo was ordered to stand trial on suspicion of heresy in 1633. The sentence of the Inquisition was in three essential parts:
    • Galileo was required to recant his heliocentric ideas, which were condemned as "formally heretical";.
    • He was ordered imprisoned; the sentence was later commuted to house arrest.
    • His offending Dialogue was banned; and in an action not announced at the trial, publication of any of his works was forbidden, including any he might write in the future.

    After a period with the friendly Ascanio Piccolomini (the Archbishop of Siena), Galileo was allowed to return to his villa at Arcetri near Florence, where he spent the remainder of his life under house arrest. It was while Galileo was under house arrest when he dedicated his time to one of his finest works, Two New Sciences. This book has received high praise from both Sir Isaac Newton and Albert Einstein. As a result of this work, Galileo is often called, the "father of modern physics"

    It sure took some time to come around to Galileo's discoveries
    Galileo was reburied on sacred ground at Santa Croce in 1737. He was formally rehabilitated in 1741, when Pope Benedict XIV authorized the publication of Galileo's complete scientific works (a censored edition had been published in 1718), and in 1758 the general prohibition against heliocentrism was removed from the Index Librorum Prohibitorum. On 31 October 1992, Pope John Paul II expressed regret for how the Galileo affair was handled, as the result of a study conducted by the Pontifical Council for Culture.


    -------------------To start video of the finished telescope click twice below on arrow lower left corner of screen.---------------------



    Galileo's Telescopes and Pieces of Telescopes. We are told ref 1a, 2a that Galileo built a number, maybe as many as 60 telescopes and lens sets, in the process of doing and reporting his famous research work, Some believe that only the objective lens of "the data scopes" is left and that's broken into several pieces.

    Not all of the telescopes he built or had built were used for research data purposes. But there are two telescopes left from this era which are very important to us today, especially a beautiful leather covered scope and a companion for comparison demonstrates what a basic research scientist has to go through to get funding for his work. A very serious problem that still exist today. There are two telescopes that are assigned to Galileo that have survived, one a roughly built paper covered working telescope, and the other a leather covered presentation telescope, both are n display at the IMSS in Florence Italy. The original leather telescope that we are replicating has become as important, in later years, as the pure research telescopes. There are at least two compelling reasons that come to mind for this.

     The first reason is because this telescope, exists because it was beautifully built. It used an ingenious wood stave design that allowed the various diameters of the scope to be easily fabricated from the same flexible construction material It was beautifully covered with leather of different colors and embossed with myriad patterns of elegant gold tooling. Since it was a piece of art it undoubtedly was treated with greater consideration which accounts for its long lifetime. So in a sense when you visits the little leather telescope or its replica be assured that Galileo intended it as a work of beautiful art for your deserving eyes and that he is personally offering it to you for your inspection.

    The second reason for its importance is that this piece of art served as a presentation instrument for Galileo when he was announcing his extraordinary findings to those of wealth and power that controlled the financing of his scientific work. He used it as a communicating tool, a grand gift to his sponsor. It still servers in this role today.
    It is a living demonstration that scientists even with their current track record still have to communicate across many borders, perhaps even gild the Lilly as Galileo did, to obtain support for their basic research work. Scientists still have to struggle for endorsements of their studies from the government and public on technically matters of great concern, such as environmental research, stem cell research, etc. It reminds us that science and religion can still be confrontational and that the military is still one of the strongest supporters of science.

     But its greatest value is that it has drawn people together to marvel at the sites to be seen in the sky through two little pieces of glass. There is a macro world out there that is still to be discovered and understood. So this famous little leather telescope, and hopefully also its replica, is still being pressed into the same service today as it was originally by Galileo in 1600. It helps people gain more enjoyment and a better understanding of the universe we share with others.


    Here is a url for a few more details of the trip:
    photos of the telescope, more of the IMSS staff,
    the museum and the country side.

    * Why is it important to make a museum grade replica in its most complete form inside and out? Why spend hundreds of hours of research and building such a replica?

    1st, One can appreciate the telescope more because it is not an almost replica, only skin deep, made out of plastic or cardboard, with an almost correct optics and dimensions. It serves as a more honest display for the public to visit and study.

    2nd, Its a tactile time capsule. It is a more complete record than a digital or paper one It is what the original telescope is today. with all of its modification over the past 400 years. Further, if for some catastrophic reason the original is lost there is at least a precise replica to help keep the record straight as to what it was like in 2006.

    3rd, Its has a greater research and teaching value. The rather unique method in construction of this telescope helps one to judge and understand the mechanical aptitudes of Galileo and his associates.

    4th, It helps one get a clearer picture of the early experimenting in the kinds of materials, tools, and techniques that had been tried for constructing telescopes as a commercial opportunity. It demonstrates another first for Galileo. A type of telescope tube construction that was the forerunner of some of the large polygon wood telescopes. and the use of resin composite construction to make telescope tubes and lens holders more rugged and resistant to the vagaries of moisture and rough handling.

    5 fifth, Then there is the poetry part of life. If one should be the lucky enough to handle and use a faithfully produced replica one would get the full experience that Galileo had when he was using the telescope, the same visual and tactual sensations that Galileo had four hundred years ago. You would find all the good and not so good design and construction issues, the cranky limited field of view, the color and other optical aberration in the image, its firm light weight constructions. Your experience would be an accurate replication of Galileo's experience giving one a more emotional appreciation for Galileo's skill and intuitive nature.

    , From a practical point of view it has higher monetary value if the instrument has been faithfully reproduced.

    There is a second question in replication often brought up for debate.

    After spending all the effort required to produce a museum quality clone inside and out (optics, supporting structure and decorations) does it make sense to destroy all this careful work with sand paper, steel wool, dyes, acids, and alkali solutions in the name of "antiquing" it?

    There are many ways of looking at this question. I've chosen four.

    1 , How would Galileo feel about this? Just put yourself in Galileo's place . You come back to your laboratory after having a tasty lunch and you find that one of your technicians has taken your most beautiful brand new presentation telescope and worked it over to make it look like it's 400 years old. Would you be upset or happy because it no longer shows the quality of materials and craftsmanship you expended?

     Would you want to show this brand new beautiful instrument as a representation of your work or antique it with sand paper, steel wool, dyes, acids, and alkali solutions? At any rate it would not be as disappointing as being put into jail for the rest of your life for interpreting the data from the telescope in a non-Church supported theory.

    2, What would you feel about Galileo's treatment of you? If Galileo were alive today and came to give you, or show you one of his telescopes for the purpose of telling you his story or to convince you to support your local scientist, would you take him more or less seriously if he presented you a with sand papered, steel-woolen, dyed, acid and alkali treated scope or a brand new carefully crafted instrument?

    3,Wouldn't visitors lose a truer connection between themselves and Galileo? Is it not better and more impressive to you or your visitors that when the telescope is presented for your inspection, that you really experience the feeling of what it must have been like to be there when the telescope was first introduced: shiny, new, and grandest in its glory rather than being presented with one that contained all the wear and tear of a four hundred year old instrument?

     4, What about giving respect and honor to those who have given us something of value in the past? Isn't the best way of honoring one of the finest, most famous, though poorly treated early experimental scientists by displaying a beautiful replication of his instrument when it was splendidly new and young just like Galileo, at the top of his world?

    inside an outside. This gives the proud owner a one upsmanship in something very famous and extraordinarily rare.



    Ref 1 The American Heritage Dictionary

    1a. Catalogue of Early Telescopes by Albert Van Helden 1999 Istituto e Museo di Storia Scienza dell Scienza, Firenzze

    2a. Sidereus or The Sidereal Messenger Galileo Galilei Translated with introduction, conclusion, and notes by Albert Van Helden The university of Chicago Press Chicago and London1989


    We thank Paul Valleli of Amateur Telescope Makers of Boston for discussions on adjustments of the focal length of the objective, recommending several source of information and generally paving a path to many resources including contacting Peter Abrahams of the Antique Telescope Society who very kindly supplied the references below. Also the is a well rounded collection of references and relevant information  pictures plus  interesting critiques maintained by Jim Mosher. Tom Pope both experience scientist.

    1, Baxandall, David. Replicas of Two Galileo Telescopes.
    Transactions of the
    Optical Society 25:3, (January 1924) 141-144. (measurements
    Galilean optics)

    2 Pettit, Edison. A Telescope of Galileo. Publications of the
    Society of the Pacific 51 (June 1939) 147-150. (#301) (replica
    by Cipriani)

    3(Galileo) Barr, E. Scott. Men & Milestones in Optics, III: Galileo
    Applied Optics 3:12 (1964) 1321-1328.

    4(Galileo) Drake, Stillman. Galileo Gleanings VI: Galileo's First
    Telescopes at
    Padua and Venice. Isis 50:3 (Sept. 1959) 245-254.

    5(Galileo) Drake, Stillman. Galileo's First Telescopes at Padua
    and Venice. Isis
    50 (1959) 245-54.

    6(Galileo) Greco, Vincenzo, G. Molesini, & F. Quercioli. Optical
    tests of
    Galileo's lenses. Nature 358 (July 9, 1992) 101. <& .pdf>

    6a V. Ronchi "Sopra i cannocchiali di Galileo," L 'Universo 4,791-804(1923)

    7(Galileo) Greco, Vincenzo et. al. Telescopes of Galileo. Applied
    Optics 32 #31
    (Nov. 1993) 6219.

    8(Galileo) Miniati, Mara. Examination of an Antique Telescope.
    Nuncius 9:2
    (1994) 677-682.

    9 (Galileo) Ringwood, Stephen. A Galilean telescope. Quarterly
    Journal of the
    Royal Astronomical Society 35 (1994) 43-50.

    10 (Galileo) Sonnefeld, August. Optical data of Galileo Galilei's
    telescope. Jena Review #6 (1962) 207-212. <.jpg>

    11 (Galileo)Westfall, Richard. Science and Patronage: Galileo and
    the Telescope.
    Isis 76 (1985) 11-30. <& .pdf,.tif>

    12 (Galileo) Zik, Yaakov. Galileo and the Telescope. Nuncius 14:1
    (1999) 31-67.
    13 (Galileo) Dupré, Sven. Galileo, the Telescope, and the Science
    of Optics in the
    Sixteenth Century: A Case Study of Instrumental Practice in Art
    and Science.
    PhD Dissertation, Universiteit Gent, Belgium, 2002. 366pp.
    14 (Galileo) Miniati, Mara, et al. Examination of a terrestrial
    telescope with the
    signature of Galileo. Optik 101:3 (Jan. 1996) 140-142.

    15 (Galileo) Greco, Vincenzo et. al. Modern Optical Testing on the
    Lenses of
    Galileo. pp110-121, Paolo Mazzoldi, ed.; From Galileo's
    Occhialino to
    16 Optoelectronics, conference Padova June 1992; Singapore:
    World Scientific, 1993.

    ref replica Hale had made

    1. Smithsonian/NASA Astrophysics Data System (ADS)

      Title: A Telescope of Galileo
      Authors: Pettit, E.
      Journal: Publications of the Astronomical Society of the Pacific, Vol. 51, No. 301, p.147
      Bibliographic Code: 1939PASP ..51 .147P ..51 .147P

    The three dimensions of science Time, length, and mass  without  them darkness prevails.

    Notes &Scraps of information putting this website together

    copy right 10/10/2005 Jim & Rhoda Morris

    All photos and written material are by Jim & Rhoda Morris unless noted otherwise. Free personal and educational use and reproduction is encouraged; Acknowledgement would be appreciated but not necessary. All commercial rights are reserved

    ***The views expressed are those of the authors and not necessarily those of the people or organization that have sponsored or helped in the project.

    Jim & Rhoda Morris


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