  From an accurate determination of the inter-quark potential, one can study
the running coupling constant for a range of $R$-values and hence estimate the
scale $\Lambda_{\overline{\rm MS}}$. Detailed results are presented for $SU(3)$
pure gauge theory from a study of a $36^4$ lattice at $\beta=6.5$. (to appear
in Proceedings of Lattice 1992 - Amsterdam)
