Some commercial plate-glass possess a structure which appears to influence the shape and directional characteristics of minute flaw formations. Geometrically oriented flaws which are believed to be due to micro inhomogeneities in the structure were found around localised stress regions. The influence of these inhomogeneous regions is reduced, but not completely removed, by remelting the glass. A dynamic spherical indentor technique was used to produce flaws under controlled conditions on various commercial glasses. The product of average flaw length and flaw number was taken as a relative measure of the total bonds broken with the given stress conditions. In remelted glasses, a linear relationship was obtained between the logarithm of flaw length and the reciprocal of melting-temperature.
