  We present results of an investigation into the nature of instantons in
4-dimensional pure gauge lattice $SU(2)$\ obtained from configurations which
have been cooled using an under-relaxed cooling algorithm. We discuss ways of
calibrating the cooling and the effects of different degrees of cooling, and
compare our data for the shapes, sizes and locations of instantons with
continuum results. In this paper we extend the ideas and techniques developed
by us for use in $O(3)$, and compare the results with those obtained by other
groups.
