The Variation In Refractive Index And Density Across Two Sheets Of Window Glass

Two panes of glass, 3ft x 2ft, have been examined for heterogeneity. The density and refractive index of variously sized samples of glass were measured over a pane using a number of different methods. The results obtained from each method are compared with the experimental error and it is shown that a variation across a pane of glass is detectable using small fragments of glass by either density or refractive index measurement. In addition, the Becke line method for the determination of the refractive index of small fragments of glass has been studied. Different immersion liquids have been investigated and the precision of different instruments is shown.