An investigation was undertaken to determine whether or not the Preston hydrostatic pressure machine, modified so that an initial pressure of 25lb per sq. in. may be obtained, is capable of predicting bottling-line production breakage by pressure tests on samples of the bottles in use. The quart and fifth-gallon bottles investigated were round, whereas the pint and half-pint bottles were of the flask type. Correlating data between production and the percentage of test breakage for quart and pint bottles are significant, and data for fifth gallons, although less significant, are definitely positive. Half-pint data yielded no significant relationship between the percentage of production breakage to test breakage, but this is probably the result of abnormal bottling-line conditions. A method of determining the range of production breakage percentage to that of test breakage by the use of the standard error of estimate is described.
