Electrically heated covered warming tray

Claim 1

A HEATING DEVICE WHICH COMPRISES, IN COMBINATION: AN IMPERFORATE FLAT TRAY STRUCTURE HAVING AN UPPER SURFACE CAPABLE OF RADIATING HEAT IN GENERALLY UPWARD DIRECTION AND MEANS FOR HEATING THE SAME; A DOME STRUCTURE COEXTENSIVE WITH SAID TRAY STRUCTURE AND DISPOSED IN COVERING RELATION THEREON, SAID DOME STRUCTURE INCLUDING AN IMPERFORATE TRANSPARENT DOME HAVING A CONCAVE INNER SURFACE FACING TOWARDS SAID TRAY SURFACE; AND MEANS SUPPORTING THE DOME STRUCTURE FROM THE TRAY STRUCTURE IN POSITION SUCH THAT THE LOWER MARGIN OF THE DOME STRUCTURE IS SPACED A PREDETERMINED UNIFORM DISTANCE ABOVE THE CORRESPONDING MARGIN OF THE TRAY STRUCTURE THROUGHOUT SUBSTANTIALLY THEIR RESPECTIVE FULL PERIPHERIES, THE SPACING BETWEEN SAID MARGINS BEING SUCH AS TO EFFECT FLOW OF AMBIENT AIR INWARDLY TO THE DOME INTERIOR, THENCE UPWARDLY THEREIN, AND THENCE DOWNWARDLY-OUTWARDLY ALONG THE INNER SURFACE OF AND FINALLY FROM THE DOME AS PREVENTS FOGGING OF SAID DOME INNER SURFACE.