NOVELTY - A thermoelectrically active material (22) in a glass cladding is drawn by heating a portion of the glass tube such that the glass partially melts and collapses under the vacuum such that the partially melted glass tube provides an ampoule containing the thermoelectric material to be used in a first drawing operation; introducing the ampoule containing the thermoelectrically active material into a heating device; increasing the temperature within the heating device; and drawing fibers (24) of glass clad thermoelectrically active material.    USE - For drawing a thermoelectrically active material (in the form of glass clad nanowires) in a glass cladding for cables used in producing thermoelectric devices, e.g. thermoelectric generators, thermoelectric refrigerators or thermoelectric heat pumps used for the direct conversion of heat into electricity, or for the direct conversion of electricity into heat.    ADVANTAGE - The method can provide high performance energy conversion and thermoelectric devices that possess significantly larger thermoelectric figure of merit (ZT) factors as compared to those of thermoelectrically active materials in bulk form. It can also produce thermoelectric devices that may be cost-effectively integrated into everyday heating and cooling products, and that provide a smaller foot-print than the industry standard.    DETAILED DESCRIPTION - Drawing a thermoelectrically active material in a glass cladding, comprises:    (A) sealing off one end of a glass tube such that the tube has an open end and a closed end;    (B) introducing the thermoelectrically active material inside the glass tube and evacuating the tube by attaching the open end to a vacuum pump;    (C) heating a portion of the glass tube such that the glass partially melts and collapses under the vacuum such that the partially melted glass tube provides an ampoule containing the thermoelectric material to be used in a first drawing operation;    (D) introducing the ampoule containing the thermoelectrically active material into a heating device;    (E) increasing the temperature within the heating device such that the glass tube melts just enough for it to be drawn; and    (F) drawing fibers of glass clad thermoelectrically active material such that the thermoelectrically active material exhibits quantum confinement.    DESCRIPTION OF DRAWING(S) - The figure is a cross-sectional view of a tubular furnace for drawing a thermoelectrically active material embedded in a glass cladding.    Vertical tube furnace (10)    Thermoelectric material (22)    Fibers (24)    Muffler tube (30)    Insulator (48)