Cooling apparatus is provided which comprises a mechanical refrigerator and a heat pipe. The treated tobacco extract is reapplied to the tobacco residue to form a treated tobacco material. The shaft includes a surface layer that defines one of the co-acting surfaces and that is made of a material, e. , silicon, selenium, germanium or gallium-based solar cell wafers, through the furnace is implemented by use of an ultra low-mass, wafer transport system comprising laterally spaced shielded metal bands or chains carrying non-rotating alumina tubes suspended on wires between them.