1. AN ELECTRIC SWITCH COMPRISING A CERAMIC ANNULAR BODY IN TWO PARTS FORMING THE INTERIOR OF THE SWITCH, A CONDUCTIVE RING INTERPOSED BETWEEN AND HERMETICALLY UNITING ADJACENT EDGES OF THE PARTS, AN ANNULAR CONTACT RING CONCENTRIC WITH THE CERAMIC BODY ON THE INSIDE THEREOF AND CONDUCTIVELY SUPPORTED ON THE INTERPOSED CONDUCTIVE RING ADJACENT THE INNER PERIPHERY OF SAID CERAMIC BODY PARTS, A CONDUCTIVE PLATE HERMETICALLY CLOSING ONE END OF THE CERAMIC BODY, A MASSIVE CONTACT STUD FIXED CONCENTRICALLY ON THE CONDUCTIVE PLATE WITHIN ONE OF SAID TWO PARTS OF THE CERAMIC ANNULAR BODY AND EXTENDING AXIALLY INTO CONCENTRIC PLANAR ALIGNMENT WITH THE CONTACT RING AND THEREWITH DEFINING AN ANNULAR PASSAGEWAY COMMUNICATING THE INTERIORS OF SAID TWO PARTS OF THE CERAMIC ANNULAR BODY WHEN THE SWITCH IS OPEN, A CAP INCLUDING A BEARING HERMETICALLY CLOSING THE OPPODITE END OF THE CERAMIC BODY, AN OPERATOR STEM SLIDABLY ARRANGED IN SAID BEARING AND INCLUDING A NON-CONDUCTIVE PORTION ADJACENT ITS INNER END AND HAVING A CORONA SHIELD MOUNTED THEREON TO EACH SIDE OF SAID DIELECTRIC PORTION, A BELLOWS HERMETICALLY INTERPOSED BETWEEN THE CAP AND THE STEM AND ELECTRICALLY ISOLATED FROM THE INNER END OF SAID STEM BY SAID DIELECTRIC PORTION, A CIRCULAR CONTACT PLATE SUBSTANTIALLY COEXTENSIVE WITH THE CONTACCT RING AND RESILIENTLY MOUNTED ON THE INNER END OF THE STEM ADJACENT THE CONTACT RING AND CONTACT STUD IS MOVABLE INTO AND OUT OF ENGAGEMENT WITH THE ANNULAR CONTACT RING AND CONTACT STUD TO PROVIDE A DOUBLE-BREAK CONTACT ASSEMBLY WHEN THE SWITCH IS OPEN AND BLOCKING SAID ANNULAR PASSAGEWAY WHEN THE SWITCH IS CLOSED, AND CONNECTOR MEANS ON THE CONTACT RING AND CONTACT PLATE.