Cooling and the SU(2) instanton vacuum.

We present results of an investigation into the nature of instantons in 4-dimensional pure gauge lattice SU(2) obtained from conngurations which have been cooled using an under-relaxed cooling algorithm. We discuss ways of calibrating the cooling and the eeects of diierent 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.