optical mirrors; electronic discharge tubes, not for lighting purposes; electric semi-conducting devices, namely, chucks, gas inlets or substate holders ; parts of all these goods included; optical lenses, optical prisms; optical glassware, in the form of discs or of plates, and etched screens for photographic purposes; all made of fused silica or of glass; optical windows, lenses, mirrors, prisms or reflectors, in particular optical windows lenses, mirrors or reflectors of natural or synthet...

FUSED SILICA OR GLASS PRODUCTS FOR ELECTRICAL PURPOSES-NAMELY, POWER LINE INSULATORS, INSULATORS FOR ELECTROSTATIC MIST AND DUST PRECIPITATORS, RINGS FOR MERCURY RECTIFIERS AND MERCURY RECTIFIERS WITH TUBES; IGNITION BASINS, IGNITION CRUCIBLES, CRUCIBLE ELECTRIC FURNACES, RADIANT ELECTRIC HEATERS, MERCURY VAPOR AND OTHER GAS DISCHARGE LAMPS, VACUUM TIGHT SEALS FOR ELECTRICAL CONDUCTORS, IGNITION SPOONS, X-RAY ANALYSIS SPECIMEN TUBES, INSULATORS FOR RADIO AND OTHER HIGH FREQUENCY TUBES, ELECTR...

Fused Silica or Glass Products-Namely, Laboratory Glassware, Laboratory Crucibles, Scientific Light Filters, Optical Mirrors, Eyepieces for Microscopes, Optical Lenses, Optical Prisms, Optical Glassware in the Form of Discs or Plates, and Etched Screens for Photographic Purposes

FUSED SILICA