The Experiment

In my research on Rembrandt's history I noticed there is currently an interesting exposition portraying 100 of his sketches in Teylers Museum.

Because Teylers is in Haarlem, I could take a quick look in preparation how to shoot that soon.

As I was there anyway I obviously visited the regular collection too and was intrigued by this old watch.

It was placed in the heart of a parabolical mirror - like a copper bowl - and was part of an antique experiment.

On the other side of the auditorium was a similar - but empty - parabolical mirror facing towards each other. The intention seemed to place your ear in the heart of the empty bowl and listen.

Despite the fact that these bowls were at least 45 feet (15 meters) apart I could clearly hear the watch on the other side of the room ticking! I also tried it with someone whispering a message that I could hear loud and clear too ;-)

This experiment developed by the Swiss scientists Marc-Auguste Pictet and Horace-Bénédict de Saussure is not only intended for transporting sound, but it also works with heat! update.... follow the link in Richard Donkins response in comments for amazing current proof!

Just imagine placing a fire source in one mirror and having it ignite something else 45 feet further!!

All in all It's not only a cool pre- 1825 experiment, it's also a nice picture!

If you use the magnifying glass to take a closer look, you might hear it too ;-))