Sudre demonstrates Solresol, 1835

On this day Sudre demonstrates Solresol publicly to blindfolded students in order to demonstrate its usefulness for blind students, in 1835.

Quoted in Limits of Language by Mikael Parkvall.

Solresol enjoyed some popularity from the mid XIX century until it was surpassed by more successful auxlangs like Volapük and Esperanto. There are still small communities of speakers of it or its more modern form, such as: https://www.sidosi.org

Check out more: https://conlang.org/resources/conlangers-calendar/