Dick. The fiddle not having frets, if you used a guitar-type capo, your open strings would sound stopped instead of open. The gadget you describe just has the effect of moving the nut down the fingerboard. That is what a guitar capo does anyway. It makes the fret in front of it act like the nut.By the way, Dick, your posting reminds me of an old joke. It is a letter to a typewriter company that goes something like:
Dear Xir,
I am writing becauxe I have found a problem in my new machine. Everytime I press an x I get an x instead. I hope you can xend me a new one xoon.
Yourx xincerely
and so on.
Murray