Johann Rudolf Rahn (1841–1912) is considered the father of Swiss art history and historical preservation. Our inventory contains 10,000 pages of his correspondence, which we have digitised and published on

Ten years after the big retrospective marking the 100th anniversary of Rahn’s death, you can now help us transcribe and edit the letters using the e-manuscripta transcription tool. At the end, we will publish your work on the online platform.

The project is part of the strategic initiative Citizen Science by Zentralbibliothek Zürich.


Would you like to continue or get started with transcribing the Rahn correspondence?

A short video tutorial offers an introduction to transcription on e-manuscripta.

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Click on the picture to start transcribing.

Transcription in progress
Letter from Rahn to Robert Durrer, 3 January 1911

To be transcribed
Letter from Rahn to Heinrich Angst, 25 March 1893

To be transcribed
Letter from Rahn to Robert Durrer, 28 December 1901

To be transcribed
Letter from Rahn to Karl Bossard, 2 March 1897


Direct access to the letters is available via selected recipients such as Heinrich Angst, Karl Bossard, Robert Breitinger-Wyder and Robert Durrer. You will find links to these in the e-manuscripta forum, with one file for each correspondent. See below for detailed profiles of these figures.

Transcriptions by Hanspeter Lanz, long-standing curator at the Swiss National Museum in Zurich, are already available for some of Rahn’s letters to Bossard, but have not yet been fed into the transcription tool. For an overview of existing transcripts that you can copy, go to the file ‘Liste_Briefe_Rahn_Bossard’ in the e-manuscripta forum. The link will take you to the digitised letter on ⁠e-⁠ The ‘File name’ column contains the name of the relevant Word file in the forum with the pre-transcription. You can copy letter transcripts from the Word documents and enter them into the transcription tool.

For other selected letters by Rahn to Angst and Durrer, we have prepared raw transcriptions with the help of artificial intelligence (Transkribus) to aid manual transcription and have made them available as Word documents. As a general rule, we do not recommend simply copying and pasting.

The Word files containing the raw transcriptions made using Transkribus can also be found in the e-manuscripta forum. These files appear at the beginning of the list of individual letters and include ‘Transkribus’ in their title information.

For Rahn’s correspondence with Angst and Durrer, for which no transcriptions are available, the page numbers have been taken over from the registers of the individual volumes in two lists and supplemented by direct links to these letters in e⁠-⁠ You can also find these lists in the e-manuscripta forum under the file names ‘Liste_Briefe_Rahn_Angst’ and ‘Liste_Briefe_Rahn_Durrer’.

Transcriptions are not yet available for letters to other addressees, so this is where you can put your reading skills to the test! We recommend starting by searching in the name register of the collections of letters. These registers were transcribed in advance of the workshop and can be searched for names using the ‘Detailed search’ option in ‘Full text search’. The pages references allow you to locate the letter you want.

To take part in the forum discussions, you must register first. Follow these instructions to find out how. Please note that your registration must be approved by the editorial team before you can log in and join the discussions. You can view and download the Word documents without registration.

Rahn’s correspondence

Jean Syndon-Faurie (Caniac-du-Causse 1869-Paris 1937), Karl Bossard, 1909, oil on canvas

Karl Bossard, 122 letters

The goldsmith Karl Bossard (1846–1914) ran an internationally renowned goldsmith’s workshop in Lucerne. He made art objects for European royal courts, private collectors overseas and museums in Switzerland and abroad. Bossard was awarded the Médaille d’Or at the Paris World Exhibition in 1889. Rahn’s letters show that he ordered mugs, bowls, platters, plates and spoons from Bossard for decades as gifts for his relatives and friends in clubs and societies.

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Robert Breitinger (1841–1913), self-portrait, 1892, gelatin silver print, Zentralbibliothek Zürich, photo archive

Robert Breitinger-Wyder, 3 letters

Like Rahn, Robert Breitinger-Wyder was born in 1841. He died a year later than Rahn, in 1913. Breitinger was a heating engineer and stove manufacturer in Zurich. At the age of 45 he began to take photographs, as did many of Zurich’s bourgeoisie at that time. Between 1886 and 1910, he produced works in a detached, matter-of-fact style. They document a phase of active urban development in Zurich. The Zentralbibliothek’s photo archive preserves his estate, including about 4,000 glass negative plates and original photographic prints.

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Heinrich Angst von Regensberg, canton Zurich. Director of the Swiss National Museum.

Heinrich Angst, 86 letters

Heinrich Angst (1847–1922), the first director of the Swiss National Museum, and the merchant Heinrich Zeller-Werdmüller (1844–1903) actively pursued the project of establishing a Swiss National Museum in Zurich. A major step in this direction was the National Exhibition in Zurich in 1883. Rahn served as an expert for the ‘Ancient Art’ group, for which Angst provided a series of glass paintings. Angst, Zeller-Werdmüller and Rahn tried to buy back Swiss glass paintings from abroad for the museum or to acquire them to prevent their sale abroad. This endeavour manifests itself in many different ways in their correspondence.

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Robert Durrer, 1934

Robert Durrer, 57 letters

Rahn consulted Robert Durrer (1867–1934), who later became the Nidwalden cantonal archivist, at an early stage in his efforts to compile the ‘Statistics of Swiss Art Heritage’ for cantons Solothurn and Thurgau. This led to Rahn entrusting Durrer with the inventory for canton Unterwalden. Their correspondence documents this professional exchange between Rahn and Durrer. Durrer’s life’s work spanned three decades and comprised an extensive book that ultimately became the prototype for Switzerland’s volumes of art monuments and for which Rahn wrote the foreword in 1899.

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The ranking is updated regularly. Version dated: 9. April 2024


Number of pages

Rüegger, Martin




Hunziker, Edith


Nuttli, Manuela


Foletti, Benedetta


Abegg, Regine


Hausheer, Yvonne


Zweifel, Thomas










Rüdiger, Tim




Segieth-Wuelfert, Floria


Vogler, Vanessa


Wehrli-Johns, Martina




At two transcription workshops on 7 May and 8 October 2022 we selected and transcribed various letters between Rahn and key correspondents. Thanks to all those who took part!


Do you have any questions or comments about the project? Get in touch!