Opening page of the US patent issued for the “Device for Projecting Stars.” Public record from the United States Patent and Trademark Office. Additional images from the same source on page 52.

50 Planetarian December 2013 Tracing paths of history Rudolf Straubel, Walter Bauersfeld, and the projection planetarium

Peter Volz 7131 Farralone Avenue #48 Canoga Park, California 91303, USA [email protected]

Part 1 relationship between these two entities we As the 100th anniversary (February 24, need to take a short trip back in time to their 1914) of the invention of the concept for the beginnings, especially of Zeiss. projection planetarium approaches, we take this opportunity to revisit the history of this Beginnings of the Zeiss company milestone event, and to explore the leading Carl Zeiss and Ernst Abbe: Optical contributions made to the invention. While workshop joins with physical sciences the name of Walther Bauersfeld (1879-1959) is Carl Zeiss founded the Zeiss Optical Co. in widely known in connection with the plan- Jena, Germany in 1846. The company manu- etarium’s invention, another lesser-known factured microscopes and lenses in an empiri- name is also of significance – that of Rudolf cal (trial and error) process. Not satisfied with Straubel (1864-1943). his production methods, in 1866 Carl Zeiss ap- Rudolf Straubel This article will highlight the persona of proached Ernst Abbe to join the company as Rudolf Straubel, his life, and career at Zeiss. research director. Based in large part on documents found in At the time, Abbe was a lecturer in physics the archives of the Deutsches Museum in and mathematics at Jena University, where to Ernst Abbe. Not having an interest in a sus- Munich and supplemented by published ac- he became a professor in 1870. Abbe succeed- tained private ownership of the company, in counts of Franz Fuchs and Bauersfeld, both of ed in perfecting a scientific approach for mi- 1889 Abbe created the Carl-Zeiss-Stiftung. whom were participants at the crucial event croscope and lens manufacturing, leading to This for-profit foundation/trust was ruled cited above, it will show in detail the rela- more accurate, predictable and economical by an elaborate set of statutes and principles tionships between Zeiss and the museum un- products at the Zeiss workshop. which included: der Straubel’s leadership at Zeiss, along with As a reward, in 1876 Zeiss made Abbe a part- •• no private ownership of the Zeiss Compa- Straubel’s personal impact on the develop- ner in his business. In 1878, Abbe likewise be- ny; ment of the projection planetarium. came director of the astronomical and meteo- •• its assets deeded largely to the University of Using documents from the family archive rological observatories in Jena. Jena; of Straubel relative Linda Langer Snook, the Finally, in 1879, chemist and glassmaker •• management of the company to be han- article will further tell the story of Straubel’s Otto Schott (1851-1935) joined Abbe and Zeiss. dled by four directors on an equal basis; retirement from Zeiss in 1933, his final years, His firm, Schott & Genossen Glass Works of •• balance of the estate donated to the em- and the fate of his family. Finally, we will ex- Jena, founded in 1884, went on to produce the ployees of Carl Zeiss. plore why his name, his contributions to the glass used exclusively in the Carl Zeiss micro- The statutes also prescribe benefits for the development of the planetarium concept, and scopes. employees, including paid vacations, sick pay, his fate, have remained largely unknown. eight-hour work day, invalid and old age pen- Since the first projection planetarium was Ernst Abbe and the Carl Zeiss Foundation sions for workers and their families, represen- built by Zeiss for the Deutsches Museum, in When Carl Zeiss died in 1888, his son Roder- tation to management, banishment of dis- order to better understand the nature of the ick Zeiss sold all assets of the Zeiss Optical Co. crimination based on race, religion, politics, and others. The Stiftung was a business and social ex- Peter Volz (born 1950) is a grandson of Zeiss optical physicist Ernst Wandersleb (1879- periment that, in its content and scope, was 1963), whose family had close ties to the Straubel and Langer families. During his child- way ahead of the times. Important in the con- hood in Germany Volz met the two Straubel sons Heinz and Harald. It was only after more text of this article is the Stiftung’s principle recently contacting Straubel's great-nephew Gerhard Langer in the US that Volz became which aims to “support science and technol- interested in the persona of Rudolf Straubel. This then led to a visit to the archives of the ogy outside as well as within the enterprises, Deutsches Museum in Munich and further research. Volz wrote the article on the sugges- and the participation in projects that served tion of planetarium historian Jordan Marché, a former editor of the Planetarian. the general good.” (10 Gale Directory of Com-

December 2013 Planetarian 51 pany Histories: Carl Zeiss AG; see also: 2 Auer- The couple had four sons: Heinz (b. 1895), Wer- to hire eight to twelve more engineers. Abbe bach) ner (b. 1897), Wolfgang (b. 1899), and Harald (b. appears to have remained skeptical vis-à-vis 1905). Straubel’s prophecy which, however, soon Transition from Abbe to the next In 1901, feeling that his strength was wan- was going to become reality. (20 Schomerus generation: Rudolf Straubel joins the firm ing, Abbe again approached Rudolf Straubel. p. 130) Abbe had hired, in 1884, the young optical This time, Straubel agreed and joined Zeiss From August 1905 to June 1907, Walther physicist Siegfried Czapski (1861-1907) to be in the role of scientific consultant. An anec- Bauersfeld also worked for Zeiss as an engi- his assistant, who then became a close associ- dote reports Abbe as saying “A weight is off neer. Bauersfeld had attracted Straubel’s atten- ate. Another “person of interest” for Abbe was my shoulders, now that Straubel has agreed tion because of his exceptional mathemati- Rudolf Straubel. Here is a short account of his to join.” (26 Wandersleb) Important for Abbe cal and engineering/construction skills. (20 early life and career before joining Zeiss. were Straubel’s scientific and managerial tal- Schomerus p. 171) Straubel was born on June 16, 1864 in south- ents. On April 1, 1908, Straubel succeeded in his ern Thuringia, the son of a protestant pastor. When Abbe resigned from actively lead- effort to have Bauersfeld rejoin Zeiss as the After attending high school in Gotha and Co- ing Zeiss on September 24, 1903, he named leading engineer, and also to join the Zeiss burg, he studied in Jena and Berlin, with ma- Straubel “scientific director for life” on the management team, replacing Czapski, who jors in physics and mathematics and minors four-member management team. The oth- had died on June 29, 1907. in mineralogy and physical chemistry. He er members were Siegfried Czapski (who also first came into contact with Abbe and Otto became “bevollmächtigter,” or power of at- The Carl Zeiss Company and the Schott in 1885. In the summer of 1888, Straubel torney of the Carl-Zeiss-Stiftung following Deutsches Museum received his PhD in Jena, with a dissertation Abbe’s resignation), Max Fischer, and Otto In 1904, the Bavarian entrepreneur and en- on an optical problem suggested by Prof. Ernst Schott. gineer Oskar von Miller (1855-1934) founded Abbe. Ernst Abbe died on January 14, 1905. Rudolf the “Museum of scientific and technical mas- From 1889 until 1901, Straubel pursued a Straubel was Abbe’s hand-picked successor, ter works” in Munich, Germany. His purpose university career in Jena, first as assistant at continuing the role of scientific head of Zeiss was “to portray scientific research in its vari- the Physics Institute until 1896, from 1893 on as established by Abbe. ous development phases, and to show the ef- as adjunct professor; then from 1897 on as full fects that mutually stimulate science and in- professor. He gave lectures and performed re- Introducing Meyer and Bauersfeld dustry from ancient times until today, in a search in numerous areas of physics, in partic- Two other persons need to be introduced as manner as instructive and as easily under- ular optical physics, but also physical chem- they would become important figures in the standable for the common people as possible.” istry, geophysics, geodesy, crystal physics, planetarium story: Franz Meyer and Walther (9 Fuchs pp. 8-9) thermodynamics and electrotechnics. (13Jen- Bauersfeld. For the astronomy department, von Miller tzsch, p. 216) On July 1, 1903, Franz Meyer (1868-1933) thought to present an historic developmental During these years, Abbe consistently kept joined Zeiss, the first engineer with a univer- series of instruments and artifacts; demonstra- an eye on the young scientist. In the late 1880s sity degree hired by the dynamically growing tions of the movements of the stars and celes- and early 1890s he tried to persuade Straubel optical company. The choice of Meyer was in- tial bodies; and a functioning observatory. (9 to come to work for Zeiss. But at that time tended to aid with the construction of large Fuchs p. 38) Straubel declined, preferring instead to be in- astronomical instruments that Zeiss had just The cooperation between Zeiss and the volved in academia rather than industry. added to its product palette. Deutsches Museum began during the year In 1894, Straubel married Marie Kern (b. According to an anecdote, Straubel told of the museum’s inception. In a letter dated 1865), the daughter of a Jewish industrialist. Abbe that, in the near future, Zeiss would need July 16, 1904, Prof. Czapski of Zeiss accepted

52 Planetarian December 2013 his election as member to the presidium sidium board, and we hope that you will board of the museum (“Vorstandsrat”), continue to give us your advice and coop- and he received a letter of thanks from eration as you have done in the past. We von Miller on July 28, 1904. Four months thank you for your already expressed ac- later, in a telegram dated November 22, ceptance of your election, and sign with 1904, Czapski also accepted to lead the assurance of our exceptional respect. section “technical optics” at the museum. Deutsches Museum, Dr. Osk. v. Miller, Dr. (1 Archive DM) W. v. Dyck, Dr. C. v. Linde.” (1 Archive DM) During its initial phase (1904-1905), the It is important to state here that, in museum solicited to observatories all his 1955 article, Franz Fuchs mentions across the country a list of articles desired the donation of the telescope by Zeiss, by its astronomy department, receiving a and quotes the letter signed “Carl Zeiss.” generally warm response. Among the re- However, he does not mention Straubel spondents was Rudolf Straubel’s broth- by name. In Fuchs’s article, Straubel is er-in-law, Otto Knopf, professor for as- mentioned only once, in connection tronomy and head of the university with Zeiss’s acceptance of the planetar- observatory in Jena. Prof. Knopf, who was ium projects in October 1913. In turn, married to Prof. Straubel’s sister Hedwig, Straubel’s membership on the presidium sent an enthusiastic response, but his ob- board is never mentioned by Fuchs. These servatory was too poorly funded he was are omissions to which we will come back unable to donate any desired items. (9 later on in this article. Fuchs p. 11) The planetarium projects The museum finds assistance In order to demonstrate the move- The Zeiss Optical Co. in Jena, being in ments of the stars and celestial bodies, von better financial shape, was able to assist Miller envisioned two mechanical devic- the new museum in its goals. On April 4, es, one heliocentric (or “Copernican”), 1906, Czapski announced that Zeiss would the other geocentric (or “Ptolemaic”). Al- furnish one model each of the most mod- Rudolf in his front yard with his solar mirror. Historical ready in 1905, the Sendtner Instrument ern reflector and refractor telescopes as photos courtesy of the Linda Langer-Snook family archive, Company of Munich had fabricated one used with permission. exhibits to the museum’s astronomy col- table-top-sized model for each of these lection. The telescopes were delivered to “planetaria” according to von Miller’s the museum in August 1908 and November have to inform you that I am still recovering specifications. But by the summer of 1912, von 1909, respectively. (9 Fuchs p. 32) from an illness and that therefore I am unable Miller had drawn up plans for a room-size Co- While the donation of the exhibition tele- to attend the annual meeting of the Deutsch- pernican planetarium with an electric motor scopes for the museum’s instrument collec- es Museum. I regret this even more because I engine, in which, similar to a clockwork, the tion was significant, Zeiss’s later contribution would have liked to thank in person for the planets Mercury, Venus, and Earth revolved to the planned observatory, and particular- honor bestowed upon me, and to personally around the sun, simulated by a light bulb in ly the construction of the Zeiss planetarium, have given you the news that the Carl Zeiss the center of the device. were to become of much greater importance. firm agrees to donate to the museum a tele- Detailed plans were sent to mechanical Donation of a telescope for the museum’s scope for the large West dome. Respectfully and clockmaker shops in Munich and other west dome observatory by Zeiss Prof. Dr. Straubel.” (1 Archive DM) parts of Germany, and were also published in On August 12, 1912, in a letter to Zeiss, the The second letter: “In response to your let- six large-volume specialty periodicals. Sever- museum wrote: “. . . In the large West dome ter from Aug. 12 we happily agree that we will al firms and individuals responded with pro- of the Museum we plan to install a telescope gladly donate for the large West dome of the posals, but all were rejected by von Miller. (9 particularly suited for demonstrations to the museum a telescope, built according to our Fuchs pp. 54-56) Initially the Zeiss firm was public, and we wish we could obtain from special construction methods, and suited par- not considered, possibly because it was spe- you such an instrument, as your company has ticularly well for demonstrations to the pub- cializing in optical products. a special reputation for construction of new- lic. We hope to soon be able to send you draw- When asking for assistance in finding com- er type lens- and reflector-telescopes.” (9 Fuchs ings and description. Respectfully Carl Zeiss.” panies having the know-how necessary for p. 40) (1 Archive DM; 9 Fuchs p. 40) executing his plans for the Copernican plane- Concurrently with the request for the tele- On November 25, 1912, Zeiss sent drawings tarium, on May 15 and May 20, 1913 von Mill- scope by the museum, von Miller had also in- and specifications of the refractor telescope to er wrote letters to Kurt Sorge, engineer and vited Prof. Straubel to become a member of its the museum. Oskar von Miller was said to be director of the Grusonwerke in Magdeburg presidium board (as Prof. Czapski was before “full of joy.” (9 Fuchs p. 40) (a Krupp subsidiary). On May 23, 1913, Kurt him) and to take part at the annual meeting of Slightly before this, on October 23, 1912, a Sorge responded, naming three companies, that board (October 2 and 3, 1912); and more- letter was sent to Prof. Straubel. “Your Excel- in which the first on the list was “Carl Zeiss in over, to become one of three secretaries of lence! This is to let you know that, during the Jena.” (1 Archive DM) that board. On September 29, 1912, two hand- meeting of the presidium board and the com- This could have been the cause for a let- written letters were sent from Zeiss to the mu- mittee on October 2 and 3, you have been ter to the Zeiss firm on July 22, 1913, asking if seum, both in Straubel’s handwriting. The unanimously elected member of the presidi- Zeiss could take on the Copernican planetar- first letter is signed “Prof. Dr. Straubel”, the sec- um board, and simultaneously to its secretary. ium project. But the response from Zeiss, dat- ond letter is signed “Carl Zeiss.” We express our particular delight that you ed July 30, 1913, and signed by Dr. Max Pauly From the first letter: “I sincerely regret to hereby join the leading members of the pre- of the astronomy department, was negative,

December 2013 Planetarian 53 stating that the project was “not in our scope torium of the Royal Bavarian Academy of Sci- the designs proposed by the museum and to of work.” It remains unknown whether Prof. ences in Munich. Prof. Straubel’s presence is view the intended locations in the new build- Straubel was involved in this response or documented in the proceedings, and his role ing of the museum. Now that von Miller final- aware of the request. as one of three secretaries is publicly men- ly had a partner in his plans for the planetari- Von Miller’s plans for the Ptolemaic plane- tioned there for the first time. Von Miller had ums, he felt a sense of urgency to press on with tarium were described on October 1, 1912: already met Straubel the day before and ex- the project. The construction plans for the “In addition to the true movements of the tensively discussed the planetarium projects new museum building needed completion. planets as in the Copernican system, in a sec- with him. Here is an excerpt from the pro- In a letter dated January 15, 1914, von Miller ond planetarium we want to demonstrate ceedings of the annual meeting: wrote: “In reference to the talks between your the rotation of the sky and the movements “…Strangely, and despite multiple efforts Herr Professor Dr. Straubel and the signed pres- of the Sun, Moon and planets as they appear on our part, no firm could be found that was ident, as well as to our letter from Oct. 3, we in the sky when seen from Earth, according willing to take on the manufacturing of these respectfully are inquiring about your progress to the Ptolemaic system. To this purpose, the large, complex and completely new con- in the preliminary work on the two planetar- fixed stars are to be shown transparently on structs (the planetaria). Then, yesterday, we ia. With utmost respect, Oskar von Miller.” (1 a sphere of about 7m diameter. In the center succeeded to convince Herr Professor Straubel Archive DM) of the sphere the observer stands on a plat- that this project would be a task particular- Not receiving a timely response, a telegram form. The sphere signifying the sky is rotating ly well suited for the Zeiss works which com- was sent to Zeiss on February 21, 1914: “Since once daily around its axis which is parallel to mand over excellent scientific and technical decision over planetaria is very urgent be- the world’s axis. This will allow that the fixed resources, as well as over the best mechan- cause of completion of building construction, stars which are visible above the horizon in ical facilities. Furthermore, taking on this we are asking for response via telegram if Dr. Munich can be positioned properly for any task would be completely in the spirit of the Fuchs can obtain the necessary information hour on any date. Furthermore, the Sun, the founders of the company, Zeiss and Abbe. in Jena this coming Tuesday. [signed] Deutsch- Moon and the planets are attached to mov- Herr Professor Straubel has expressed the sup- es Museum.” (1 Archive DM) able arms, so that the apparent movements port of his firm in the construction of the gi- On the same day (February 21), Zeiss re- of these celestial bodies underneath the fixed ant planetaria, and I therefore have no longer sponded: “Dr. Fuchs welcome anytime. stars can be executed in their corresponding any doubt that we can expect superb results [signed] Zeiss works.” (1 Archive DM) times, which will allow the demonstration of with these museum objects as well.” (1 Archive the various conjunctions of the planets.” (1 Ar- DM VB 1912-1913 p. 32) A momentous meeting chive DM) On October 3, 1913, two days after the an- The result of this exchange of telegrams nual meeting, the museum wrote to Zeiss: “In was the momentous meeting on February Discussing projection techniques reference to the talks between your Herr Pro- 24, 1914 in Jena, with these participants: Prof. In the summer of 1913, the instrument com- fessor Dr. Straubel and our president, Herr Dr. Dr. Straubel, Dr. Walther Bauersfeld, Obering- pany Sendtner in Munich again built a mod- Oskar von Miller, we would like to express one enieur (chief engineer) Franz Meyer, all from el according to this description by von Mill- more time our delight over the fact that you Zeiss, and Dr. Franz Fuchs as envoy of the er. But, back in 1912, the first notions of using are willing to construct the two planetaria ac- Deutsches Museum (9 Fuchs p. 61; 3 Bauersfeld optical projection techniques to demonstrate cording to Copernicus and Ptolemy for the p. 75). Note that Oskar von Miller himself was the movements of celestial bodies in a geocen- new building of our museum.” (1 Archive DM) absent from the meeting. tric model had been discussed. One such idea This, in fact, meant that Straubel accepted Fuchs later described the results of the involved using a film to project the move- to take on both the Copernican and the Ptole- meeting with these words: “In Jena I was read- ments of the sun, moon and planets. maic planetariums on Zeiss’s behalf. ily shown the plans for their intended designs. A more significant projection idea origi- That Straubel was able to commit Zeiss’s re- For the Copernican planetarium, they wished nated from Swiss educator Eduard Hinder- sources on such a short notice, without pri- to increase the room height, however this mann, who used “shadow”-like projections or internal discussions at the firm, speaks for wish could not be granted because of our large of the motions of the planets, to demonstrate his enormous influence within the company concrete structures. With respect to the Ptol- their ribbon-like movements when seen from at that time; for his conviction of how impor- emaic planetarium, thoughts were presented Earth. tant he considered the work of the Deutsch- to project the sky onto a white, fixed dome us- Hindermann wrote in a letter to von Mill- es Museum and Zeiss’s support of it to be, in ing high-quality optics, instead of construct- er, dated February 4, 1913: “The idea of using the spirit of Abbe as expressed in the Zeiss-Stif- ing the rotating metal sphere.” (9 Fuchs pp. 61- light projection can of course be applied and tung principles; and lastly, how important he 62) used with advantage when simulating the personally considered the planetarium proj- However, a more in-depth description of view of the world according to the Ptolema- ects to be. this meeting originates from Walther Bauers- ic system, as I will gladly discuss with you.” Of course, having the name of the Zeiss feld, in an article published in 1957: Fuchs, von Miller’s deputy, wrote: “Von Mill- works and their scientific and technological “The author, who had been a member of er wants to preserve the priority and remarks: prowess displayed so prominently at this new the Board of Management in the Zeiss works ‘Fuchs, write down exactly when we received museum could also reap tremendous long- since 1908, attended a meeting at Jena be- this letter, and when the drawings showing term public relations benefits. This would tween Oskar von Miller and the chief engi- the movement of (the planet) Mercury have have been an important factor in his decision neer [Meyer] of the astronomical department been shown to us’.” (9 Fuchs p. 58) as well. of the firm. On this occasion much was dis- cussed about the difficulties of the construc- Oskar von Miller discusses planetarium From acceptance of the plans to the tion, which appeared insurmountable. In this plans with Straubel projection planetarium concept situation I asked the question: ‘Why do you The tenth annual meeting of the presidium On October 7, 1913, less than a week after want to make such complicated and heavy board and committee of the Deutsches Muse- the announcement by von Miller, Zeiss engi- machinery? I think a much better way would um took place on October 1, 1913 in the audi- neer Franz Meyer was sent to Munich to study (Continues on Page 82)

54 Planetarian December 2013 Rudolf Straubel, continued from Page 54 museum archive contains the proceedings of a Meyer’s letter, he proposed a solution for the be gained by optically projecting the pictures meeting at Zeiss in Jena on July 7, 1917. Present difficulties encountered by Meyer of project- of the heavenly bodies on the interior surface were Prof. Straubel, Dr. Bauersfeld, Wieland, ing the stars. In addition, he now took over of the sphere. In this case all the complicated Becker (all Zeiss), and Oskar von Miller (DM). from Franz Meyer the task of designing and mechanical machinery could be replaced by a On the agenda were the current state of the building the Ptolemaic planetarium projector. fairly small arrangement of optical apparatus work on the planetarium projects, and plan- The following comment, dated Septem- in the midst of the sphere.’ ning of detailed steps to advance the projects. ber 29, 1942, and signed “Bfd” for Bauersfeld, “Immediately after I had spoken these Franz Meyer was unable to attend the meet- was found handwritten on the side of a typed words, my colleague in the Board of Manage- ing, but was sent to Munich shortly thereafter copy of Meyer’s letter: “This letter was routed ment, Professor Straubel, who also had attend- to continue the discussions on site. (1 written to me by the author before it could be mailed; ed the meeting, exclaimed: “Then of course, report, Archive DM) therefore I was able to prevent it from being also the fixed stars should be projected from sent. It gave me reason to take on myself the the central apparatus.” This was the moment Work on projector can resume construction of the projection planetarium in which the Zeiss-Planetarium was born. Os- After the end of World War I on November since I was no longer convinced that the pro- kar von Miller and all members of the meet- 11, 1918, following the end of war production jection idea which originated with me could ing were very happy about this solution and amidst a considerably decrease in civilian be realized without my continual assistance.” which, moreover, allowed enlargement of production at Zeiss due to a sharp decrease in (17 Meier pp. 91-92) the dimensions of the spherical dome so that exports, the work on the planetariums could The events of March 1919, and the follow- many more visitors could see the artificial sky now be resumed with increased effort. ing stages in the construction of the appara- simultaneously, and the astronomical depart- The next event of crucial significance oc- tus, have been described by others, especial- ment was charged with designing the appara- curred in March 1919. Franz Meyer, who was ly in much historical and technical detail by tus in this form.” (3 Bauersfeld p. 75) then in charge of the project, had prepared a Ludwig Meier. (17 Meier) Therefore, we only We will discuss the Bauersfeld article and letter to the museum, dated March 21, 1919, in mention the main events from here on. particularly the “birth moment” in a separate which he suggested abandonment of the pro- Franz Meyer continued work on the Co- section below. jection of the fixed stars due to what he be- pernican planetarium, while Walther Bauers- When informed by Dr. Fuchs about the lieved to be insurmountable difficulties, and feld was now in charge of the projection plan- new design idea for the Ptolemaic planetar- to return to the original mechanical design of etarium. On October 17, 1922, Zeiss sent in the ium, Oskar von Miller was very pleased. In a a rotating metal sphere. patent request for the planetarium projector. letter dated March 20, 1914 he reflected on the His proposed change did not affect projec- From July to September 1923, trial runs of the new design. Beginning in April, he personal- tion of the planets, sun and moon. new device were performed in Jena, in a dome ly travelled to Zeiss in Jena, and upon his re- Bauersfeld, who found this letter on his constructed on top of a Zeiss factory roof. turn to Munich, in a letter dated April 6, 1914, desk for approval, intercepted it and prevent- Significant participation by Bauersfeld in he summed up his discussions in Jena with an ed it from being sent. (17 Ludwig Meier pp. 91- the correspondence with the Deutsches Mu- endorsement of the new plans. (9 Fuchs p. 61) 92) seum started on September 17, 1923, follow- According to Bauersfeld himself, on March ing von Miller’s request to have the projector Projection planetarium: From concept 24, 1919, just three days after finding Franz shipped to Munich for demonstrations to the to reality After this endorsement of the new plans by von Miller, the actual work on the planetari- ums began at Zeiss. But because World War I broke out less than four months later, on July 28, 1914, the preoccupation with war produc- tion at Zeiss slowed the work on the planetar- iums down to a crawl. Nevertheless, the coop- eration continued. Chief engineer Meyer was put in charge of the actual work on the planetariums and on occasion was sent to Munich, to take part in discussions and decisions concerning the building of the domes where the Zeiss plan- etariums and the Zeiss telescope were to be housed. (9 Fuchs pp. 47-48) The correspondence between Zeiss and the museum also continued. Letters from the mu- seum to Zeiss usually are addressed to “Prof. Dr. Straubel, Direktor der Zeisswerke.” Let- ters from Zeiss to the museum typically are signed by Dr. Walter Villiger, now head of the astronomy department at Zeiss, though some of them additionally show Straubel’s initials (“Str”). (1 Archive DM) Despite the war, von Miller continued to push for advancement of the projects. The

82 Planetarian December 2013 presidium board during its annual meeting. signatures of Zeiss management members and the Carl-Zeiss-Stiftung in Jena.) Only after von Miller had travelled to Jena Czapski (9 p. 32) and Bauersfeld (9 p. 63), but 3 Bauersfeld, Walther. “Projection Planetar- in person did Bauersfeld reluctantly grant his Straubel’s signature is not shown. ium and Shell Construction.” Part 1. The wish. Furthermore, the singular statement Engineer (Proceedings of the Institution of shown above seems quite curt. Fuchs men- Mechanical Engineers) 171 (17 May 1957): 75- Demonstrating the device tions Straubel’s membership on Zeiss’s board 80. (German: Bauersfeld, Walther. “Projek- Demonstrations were held in Munich from of management, but omits his role as scientif- tions-Planetarium und Schalenbauweise.” October to December 1923, and then the de- ic director of Zeiss. This is all the more aston- In: Zeiss-Werkzeitungen, 1957 Heft 28 p. 87. vice was returned to Jena for final work. On ishing since Fuchs was von Miller’s right-hand Carl Zeiss, Jena.) April 3, 1924, the patent for the projector was man, from 1904 throughout the entire period 4 Bauersfeld, Walther. Das Zeißische Projek- granted, issued to Walther Bauersfeld. of the planetarium projects and beyond. tions-Planetarium. Verlag Dr. S. V. Jezewski. Much to the dismay of von Miller, who Straubel’s donation of the Zeiss telescope Jena 1925. wanted to retain the novelty aspect of the for the observatory, his significance in Zeiss 5 Becker, Markus. “From Entrepreneur to Or- planetarium for its intended location at the taking on the planetarium projects, and his ganization: The Replication of Individual museum, public demonstrations of the pro- membership in the presidium board of the Habits.” Paper presented at the 2010 sum- jector were held in Jena on the factory roof- museum all must have been known to Fuchs. mer conference, “Opening Up Innovation: top from August to October 1924. In fact, Fuchs must have had personal contact Strategy, Organization and Technology.” Finally, on May 7, 1925, the new collections with Straubel on various occasions, such as at Imperial College London Business School, building of the Deutsches Museum in Munich the crucial meeting on February 24, 1914 in June 16-18, 2010. was officially opened in a ceremony. Simulta- Jena. In light of these facts, Fuchs appears to 6 Boegehold, H. “Rudolf Straubel zum siebzig- neously on that day, the projection planetari- show a decided reluctance towards mention- sten Geburtstage.“ Die Naturwissenschaften um, using the Zeiss Model I projector, and the ing Straubel by name. 25 (1934): 421-424. Copernican planetarium, also built by Zeiss, Fuchs’s intimate familiarity with the histo- 7 Duwez, Pol. “The Solar Furnace.” Engineer- were opened to the public. ry of the development of the Deutsches Mu- ing and Science 19 (Feb. 1956): 13-16. Quote: On the day of the opening, the Deutsches seum, particularly with its astronomy depart- “With a glass parabolic mirror of about six Museum honored a significant number of per- ment, is the reason why his article from 1955 feet in diameter and a focal length of two sons with its highest honor, the “Goldene Eh- has been so widely used as a key reference in feet, Straubel was able to reach tempera- renring” (golden ring of honor). Among the the history of the projection planetarium, and tures of the order of 3000 degree Celsius recipients were two persons from Zeiss, recog- rightfully so. (~10000 degree Fahrenheit)” (on p.14). nized for their contributions in building up In turn, Fuchs’s lack of mentioning Straubel 8 Email communications to the author the astronomy department of the museum: could help to explain why Straubel’s contri- from Dr. Röschner and Dr. Füßl, Archive, Prof. Dr. Rudolf Straubel and chief engineer bution to the planetariums has not been rec- Deutsches Museum. Franz Meyer. (8 Archive DM) ognized in so many other accounts. The fact 9 Fuchs, Franz. “Der Aufbau der Astrono- While the honoring of Franz Meyer by the that Fuchs does not directly mention that mie im Deutschen Museum (1905 - 1925).“ museum has been cited in the literature (20 Straubel was present at the annual meeting in Deutsches Museum Abhandlungen und Beri- Schomerus p. 131), mention of Rudolf Straubel 1913, for example, caused planetarium histo- chte 23, no. 1 (1955): 1-68. also receiving this honor has not been found. rian Ludwig Meier to invent a fictional tele- 10 Gale International Directory of Company Straubel’s membership on the muse- phone conversation between von Miller and Histories: “Carl Zeiss AG.” um’s presidium board continued through- Straubel, and to mainly credit von Miller’s ir- 11 Hermann, Armin. Nur der Name war gebli- out World War I and is documented until at resistible persuasiveness with Zeiss’s accep- eben–Die abenteuerliche Geschichte der Firma least January 1920. Noteworthy is a telegram tance of the planetarium projects. (17 Meier Carl Zeiss. Deutsche Verlags-Anstalt, Stutt- sent to von Miller on May 24, 1918, in which pp. 85-86) gart, 1989. Straubel announced the donation by Zeiss of Although it is not known with certainty 12 Herzberger, Maximilian. “The Scientific fifty thousand mark for the construction of why Fuchs did not give Straubel the warrant- Work of Constantin Rudolf Straubel.” Jour- the museum’s library building. (1 Archive DM) ed credit for his contributions, we will offer nal of the Optical Society of America 44, no. 8 a possible explanation at the end of this arti- (August 1954): 589-592. Discussion: The lack of credit given to cle. Fortunately, the archive at the Deutsches 13 Jentzsch, F. “Rudolf Straubel zum 70. Ge- Straubel by Franz Fuchs Museum has the documents to complement burtstag.” Zeitschrift für technische Physik In his 1955 article “Aufbau der Astrono- Fuchs’s otherwise excellent historical account 1934 Nummer 6. mie im Deutschen Museum,” Franz Fuchs, of the planetarium history with accounts 14 Julius Rosenwald correspondence, Museum a long-term division chairman there, men- crediting Straubel’s contribution. of Science and Industry (MSI) Archives, Chi- tions Straubel only once (12 Fuchs p. 59), with Will continue in the next issue. cago. these words: “Despite the previous rejection 15 Langer Snook, Linda. The Langers of Jena. by Zeiss, on Oct. 3, 1913 von Miller thoroughly References Charleston, SC: privately published, 2012. discussed this matter which he felt so strongly 1 Archive, Deutsches Museum, München. If 16 Marché II, Jordan D. Theaters of Time and about with Prof. Straubel who was a member not indicated otherwise, documents are Space: American Planetaria, 1930-1970. New of Zeiss management.” (Note that the correct from the folders “Korrespondenz Astrono- Brunswick, N.J.: Rutgers University Press, date of the discussion was September 30, 1913) mie” or “Allgemeine Korrespondenz.” 2005. Given the consistently courteous and rev- 2 Auerbach, Felix. Das Zeisswerk und die Carl- 17 Meier, Ludwig. “Die Erfindung des erent attitude towards Straubel found in Zeiss-Stiftung in Jena–Ihre wissenschaftliche, Projektionsplanetariums.“ In: Jenaer Jahrbu- the museum’s correspondence, the lack of technische und soziale Entwicklung und Be- ch zur Technik- und Industriegeschichte, Straubel’s mention by Fuchs appears surpris- deutung, 5th ed. Gustav Fischer, Jena 1925. Band 5, 2003. I ing. In his article, photos are included of the (English: Auerbach, Felix. The Zeiss Works

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