Magnetically controlled mercury wetted switch and electrical relay incorporating such a switch

A switch comprising:

• a base having a planar surface, a cover placed over said planar surface so as to define therewith a closed space, a plurality of electrodes of ferro-magnetic material passing through said base and surface into said space, electrically insulating glass/metal welds surrounding said electrodes in said base to seal said electrodes with respect thereto, the planar surface of said base and the interior surface of said cover and the surfaces of said electrodes inside said space being wetted by an electrically conducting liquid, said welds being the only surfaces of said space not wetted by said liquid, one of said plurality of electrodes forming a common contact, at least one elongated plate of ferro-magnetic material arranged in said space and extending substantially perpendicular to said planar surface of said base, said plate being movable about a liquid hinge formed by capillarity by the conductive liquid wetting the common electrode and plate surface, said plate being adapted to bear against said at least one other electrode and to be held thereagainst by surface tension so that electrical current may pass from said common electrode to said at least one other electrode.