When clay bricks were fired at various temperatures between 900° and 1050°C and subjected to a heating-cooling cycle (20° to 1050°C) in a dilatometer, the magnitude of the length anomaly at 573°C, due to alpha quartz-beta quartz inversion, and that of residual shrinkage were found to be a function of the temperature at which the bricks had originally been fired. This was true also for the magnitude of the endothermic heat effect determined by differential scanning calorimetry. It is suggested that these methods be utilized to determine the firing temperature of brick as an index for quality control purposes. -- AATA