Several years back I met a fellow who collected and restored unusual
musical instruments in addition to being an amateur organ builder.  As
an example he claimed to have two Theremins and an "Ondes Martenot".

He passed away soon after that first contact and I never found out what
an "Ondes Martenot" is.  I got the impression at that time that it was
an electronic novelty, but I am not sure of that.  Does anyone know
what this is and has some details on it?

I also like to make a comment on the recent discussions about
bioscopes.  During my childhood years, while living in the Netherlands,
the highlight of the yearly fairs, or "Kermis" as we called it, was
for us country kids to see a movie in the "Bioscoop", as we spelled it.

The bioscope was a rather large tent with benches for seats ala
auditorium style.  The name as posted on the outside was "Welte
Bioscoop".  Now that I know a trifle more about the world of mechanical
music I wonder if there was any connection to the well known Welte
family of organ, etc., builders.

As an aside, the fixed movie theatres were also known as "bioscoops"
and they may still be called that.

Albert de Boer