  The superconducting transition temperature Tc has earlier been correlated
with coherence length and effective mass for a series of heavy Fermion (HF)
materials at atmospheric pressure. Here, a further physical property, the dc
electrical conductivity sigma(Tc), is one focal point, another being the
pressure dependence of both Tc and sigma(Tc) for several HF materials. The
relaxation time tau(Tc) is also studied in relation to an Uncertainty Principle
limit, involving only the thermal energy kB Tc and Planck's constant.
