The phenomenon of has existed since 2011 at TU Delft: 2 times per year, a performer, artist, or other creative person is appointed in order to introduce the students to a world that does not revolve aroundas technology. This spring, Erik de Jong, better known as Spinvis, is Cultural Professor. The theme of his professorship is “Out of Nothingness”.

Text: Marietje Ruijgrok
Photos: Jan van der Heul

Every time a Cultural Professor is appointed, TU Delft Library exhibits material from the special collection (full of heritage pieces) that has to do with the professor’s theme. For Professor too, we have found very suitable items:

  • The French postman Ferdinand Cheval
  • Simon Stevin’s music theory
  • The tuning fork or diapason

The French postman Ferdinand Cheval (1836 – 1924)

From the moment that he tripped over a curious stone, the French postman Ferdinand Cheval dreamed about a palace the likes of which had never been built. The next day he returned to that spot and began to collect more stones. With the stones he collected he began to build a fantasy construction using cement, loam and gauze.

He did this for the next 33 years during his daily postal route from Hauterives to Tersanne (situated in the Drôme department in south-eastern France). This construction is the source of inspiration for the project that Spinvis wants to carry out with his students.

Source: Book: Le facteur Cheval (1969), Auteur: Alain Borne

Simon Stevin’s musical theory

His Wisconstighe Gedachtenissen (Mathematical Memoirs, 1608) includes the ‘Spiegheling der Singconst’ (Theory of the Art of Singing) mentioned in the ‘Ghemendge stoffen’ (Various Material), but the contents are missing. And yet, Stevin had already announced his music theory in 1585, in L’Arithmetique (p. 57). Fragments of it were discovered at the end of the 19th century in Principal Works V.

With ‘singconst’, Stevin does not mean the art of singing, but music in general. And ‘spiegheling’ is theory for him, which must always be in service of ‘daet’ (practice). The Spiegheling der Singconst is about the intervals in a scale. Together, three ‘pure’ thirds don’t quite make an octave. So there was a problem with those intervals, and that was important in the construction of a lute – where to put the ‘grips’ (the frets on a guitar), and in the tuning of organs and harpsichords. In practice, various solutions were found. Vincenzo Galileï had preceded Stevin with the requirement that all twelve half intervals should be equal (he adopted the 18:17 ratio, a good approach). Stevin arrived at the exact value: the twelfth root of 2. His distribution of the octave is now known as equal temperament.

It is by no means certain whether Stevin made music himself. Maybe in those days, the fact that the twelfth root of 2 is the ‘true ratio’ could only be said by “a mathematician who was not completely up to date on musical performance practice”. It is striking that Stevin makes no mention of the beating that can be heard during the tuning of an instrument.
Insight into the physical principles of sound had not progressed much further than, ‘it is a vibrating movement’. Tones were low or high, coarse or fine. Nowadays we cannot properly imagine how a theory of sound could be attempted without the concept of frequency. Stevin writes: “And it is not possible to use one’s hearing to judge all ratios between two perceived sounds.”.

Source: D. Bierens de Haan, Bouwstoffen voor de Geschiedenis der Wis- en Natuurkundige Wetenschappen in de Nederlanden. Volume Two.

The tuning fork or diapason

A tuning fork or diapason is a double-toothed, metal fork that emits a tone on vibration with an accurately known standard pitch.
A good tuning fork barely produces overtones, and the sound approaches a pure sine wave. The invention of the tuning fork is ascribed to John Shore in 1711. John Shore was Sergeant Trumpeter to the English court. Both Purcell and Händel wrote trumpet pieces specially for him.

In order to hear the soft tone of a tuning fork well, the round end of the tuning fork is sometimes held against the head (bone conduction) or attached to a resonator or pressed against the surface of a table, for instance.

TU Delft Library Special Collections , (1925-1950)

Exhibition of master class results

The master class for students is part of the Cultural Professorship. From 7 June on, the results of this will be exhibited in our central hall. The theme of this master class is “The dreamed front line of my field of study”.

Take a look at the objects

Do you want to look at these objects? You can! Visit the Treasury, where ‘the inspiration of Cultural Professor Spinvis’ is displayed, or check out our photos on Flickr.

Discover the collection

Also take a look in the Treasury area itself, where we always display material from our special collections. Are you looking for material from our collection? Please feel free to contact us.