Paper 1: Graphical methods are demonstrated for solving the usual trial-and-error problem of computing the percentages of several aggregates blended to make the combination conform to specifications, for showing how the same graphical solutions can be expanded to include calculations for the most economical blend, and for explaining how the diagrams can be combined with accounting records and routine test results to provide a method for selecting blends on the basis of the probability of rejection of the final product. Paper 4: Binary glasses of the oxides of sodium, potassium, lithium and lead with silica were tested as reactive aggregates with high- and low-alkali cements and with high-alumina cement and pressure-calcined gypsum plaster.