Galileo's Telescopes: To Date These Are The Worlds Finest Museum Quality  Replicas 
Made on Order by Jim & Rhoda Morris

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09/18/2007 02:00:37 PM Last updated
A visit to the home  of the Original "Galileo" Telescopes

 The Institute and Museum of the History of Science Florence Italy
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, curator at the 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 of the moons of Jupiter and the craters and mountains of our Moon.

The objective end of the famous Number 2 telescope, IMSS #2428, with its beautiful art work.

A trip to the IMSS in Florence Italy to take pictures, view pictures in the archives, and make measurements on the original. There seemed to be fairly reasonable data in the literature on the optical performance of the Galileo original telescopes  which are on display at the science museum where Galileo's telescopes are kept 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 exhibition wing of the Griffith Observatory.

We were concerned about the

  • dimensions of the various components

  • specific construction details

  • materials used, and

  • exact nature of the gilded decorations

    Acknowledgments and an unexpected finding
    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.  all the members of 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 telescope were a break through for us.  It allowed us to 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 our goal of making a precise replica throughout and worthy of display at 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 technique 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's use shows the advanced understanding of composite construction methods allowing higher volume production and achieving a product strength to weight ratio that is the envy of today's builders. Last but not least it yields good mechanical stability resisting the normal warping of the wooden parts. See below for a further discussion of this subject.

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

    Franca Principe, on the right, IMSS staff member, who took the excellent photographs before and after the recent restoration.

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

    Sabina Bernacchini, IMSS staff member, 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 dimensions, method of construction, and the gold tooling design information.

    .The tools and methods we 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's 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, one of our setups for taking the overall dimensions, and views 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 replaced 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.

    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 including 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.


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

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    Copyright 04/18/2007 Jim & Rhoda Morris