Louis-Bertrand Castel
«Ocular Harpsicord»

In almost every publication on the history of how image and sound relate, the ocular harpsichord is cited as a forerunner in the field. From Castel there exists only a series of texts, some of which include precise functional descriptions, dating from the years 1725 to 1740.
Here he develops a theory on the physical connection between image and sound, thus dismissing his contemporary Isaac Netwon and giving new meaning to older ideas by Athanasius Kircher. Still, there is no proof that Castel ever built this apparatus, not to mention that it functioned. Reacting to criticism from his contemporaries, he energetically refuted ever intending to build the apparatus at all, arguing that he was an «architect» and not a «carpenter,» and that whoever wished to build it should feel free to do so.
The history of this ‹virtual› machine becomes only more confusing through discussions of that time, which engage great thinkers, but whose literary form also gives the impression that Castel’s apparatus exists. In 1739, for example, the German composer Georg Philipp Telemann published an anonymous eyewitness report, «The Ocular Organ or Ocular Harpsichord.» Accompanied by a deaf mute, the encyclopedist Diderot paid Castel a visit in 1751, to test whether or not this subject could experience music for the first time in his life, through his eyes alone. In the end, the visit was obviously no less disappointing than the one Jean-Jacques Rousseau made, who writes: «This man is crazy but otherwise a good person. He seems to me to be the kind of original thinker that one should encourage to work through what he discovers on paper, instead of encouraging him to make newer discoveries.» This led to Castel becoming the forerunner of all the manic, nineteenth and twentieth-century hobbyists-inventors who worked at developing color-organs and similar instruments.


Zitat O-Ton: »Cet homme est fou, mais bon homme au demeurant. Il me paraît de ces esprits originaux dont il est plus à propos d'encourager à démontrer de qu'ils découvrent, que les encourager à faire de nouvelles découvertes. »

Further bibliographic references:
Jean-Marc Warszawski, Le Clavecin oculaire du père Louis-Bertrand Castel. In: Michel Costantini, Jacques Le Rider, François Soulages, Hg., La couleur Réfléchie, Séminaire à l'Université Paris VIII, mai 1999, Paris 2001(L'Harmattan)

Joachim Gessinger, Visible sounds and audible colours: The ocular harpsichord of Louis-Bertrand Castel. In: Beate Allert Hg. Languages of visuality. Crossings between Science, Art, Politics, and Literature, Detroit 1996 (Wayne State University Press) (= Kritik. German Literary Theory and Cultural Studies), pp. 49–72

Claude Lévi-Strauss, Sehen Hören Lesen, München /Wien 1995, pp. 121–123

Dieter Daniels