1. A MAGNETICALLY OPERATED SWITCH STRUCTURE COMPRISING A PAIR OF SPACED PARALLEL BARS OF MAGNETIC MATERIAL EACH HAVING A CONTACT PORTION ASSOCIATED THEREWITH, SAID CONTACT PORTIONS BEING POSITIONED IN FLUX LINKING RELATIONSHIP WITH EACH OTHER, ONE OF SAID CONTACT PORTIONS BEING MOVABLE TO MAKE AND BREAK AN ELECTRICAL CONNECTION BETWEEN SAID BARS, AN ENCLOSING ENVELOPE WITHIN WHICH THE SAID CONTACT PORTIONS OF SAID BARS ARE ENCLOSED WITH THE REMAINDER OF SAID BARS EXTENDING EXTERNALLY OUT OF ONE END OF SAID ENVELOPE AND SEALED THERETHROUGH IN A VACUUMTIGHT MANNER, ADJUSTABLE PERMANENT MAGNET MEANS COMPRISING A FERRITE ANNULUS ASSOCIATED WITH THE SAID EXTERNAL PORTION OF SAID BARS, AND A FLUX GENERATING WINDING ASSOCIATED WITH THE SAID CONTACT PORTION OF SAID BARS, THE SAID MOVEMENT OF THE CONTACT PORTION OF SAID BARS BEING JOINTLY CONTROLLED BY SAID PERMANENT MAGNET MEANS AND SAID FLUX GENERATING WINDING MEANS.