With the return of the original telescope from 1864, the year the observatory was founded, ETH is taking a further step towards collecting, documenting and preserving its architectural and scientific heritage.
In late August, ETH Zurich restored the Semper Observatory’s historical telescope to the observatory dome. The so-called refractor had been returned to Kern, one of the two manufacturing companies, in 1982 after the observatory ceased research operations. In 1988 it was transferred into the depot of the Stadtmuseum Aarau.
The telescope was assembled by astrophysicist Thomas Friedli, who was among the last to conduct research at the ETH observatory.
The return was part of the Holdings of ETH Zurich Architectural Culture project, run by the Real Estate Management department. It coincided with the collection of scientific instruments and teaching materials in the ETH Library.
Holdings of Architectural Culture at ETH
When a historical (and often listed) ETH building is renovated, sometimes certain features and furnishings have to be removed, despite their value in representing the craftsmanship and culture of the era in which they were created.
Before any structural changes are made, these priceless testimonies to architectural history are identified on site, recorded and stored centrally. In 2020 the Real Estate Management department established the Holdings of Architectural Culture inventory to carry out this process. Its purpose is to procure and document furnishings, fittings and representative building components.
Anastasia Paschou is the Project Manager, she says: “We have scoured the basements at ETH and discovered hundreds of objects from earlier construction periods. We’ve collected them in a repository, documented them thoroughly and tried to tell their story online, focusing on the history of how they were fashioned or installed and how ETH has changed.”
By collecting and creating inventories for these items, ETH is following the strategy of the federal government and is a role model in the field of architectural culture.
Paschou says: “An object’s significance as a testimony to architectural culture diminishes when we remove it from its spatial context. A chair can reflect craftsmanship, but its unique cultural value for ETH depends on the connection between object and spatiality. Where was the chair located, and when? What did the rooms look like back then? How have the university’s buildings, rooms and chairs changed since? When we tease out these details and make old objects available to the public, what we’re really doing is using knowledge to build bridges between the past and present.”
Another goal of the project is therefore to return certain objects to their original locations, exhibit them there and, if possible, invite the public to view them.
Take a look at the Holdings of Architectural Culture
At the moment, building culture collections can be viewed at two exhibitions:
Astronomical instruments in the observatory
The foyer of the observatory was rebuilt in 2022, a collection of observatory founder Rudolf Wolf’s astronomical instruments are now housed in their original location as part of a permanent exhibition. The exhibition is open to the public Monday to Friday, 8 a.m. to 6 p.m.
An individual guided group tour of the Semper Observatory can also be booked through ETH Zurich Tours.
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The permanent exhibition in the observatory foyer is open to the public. (Photograph: ETH Zurich / Ufuk Düzgün) -
Important historical instruments are on display there, including the telescope used by the observatory’s former director, Rudolf Wolf, to study sunspots. (Photograph: ETH Zurich / Ufuk Düzgün) -
This theodolite – a precision instrument for measuring angles – from the estate of the geodesist and astronomer Johannes Eschmann (1808–1852), was used to gauge the position of stars. (Photograph: ETH Zurich / Ufuk Düzgün)
Exhibition of the Holdings of ETH Zurich Architectural Culture
A selection of prized building components and furniture are on display in the Holdings of ETH Zurich Architectural Culture show. It will be shown in the (still) empty hall of the machine laboratory as part of the external pageEuropean Heritage Days under the theme "Repair and Recycle".
The exhibits come from ongoing projects – such as the renovation of the Machine Laboratory building (2018–2023) and the Main Building’s underground car park (2021–2023) – and construction projects that have long since been completed.
The exhibition can be seen once again as part of external pageOpen House Zurich on Saturday, September 30, and Sunday, October 1, from 10 am to 5 pm. There will be a guided tour on building culture at 2:45 p.m. each day.
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This double-leaf wooden door from 1881–1890 was the entrance to the former physics building. (Photograph: ETH Zurich / Ufuk Düzgün) -
A historical photograph of the door. (Photograph: ETH-Bibliothek Zurich / Bildarchiv) -
The Holdings of Architectural Culture exhibition opened in May 2023 in the main building of ETH Zurich. (Photograph: ETH Zurich / Ufuk Düzgün)
