In Table 40 are given the results of tests on four brands of Portland cement at seven days, twenty-eight days and two years. From the tests at two years it appears that T and U are the best cements, V is nearly as good, but W gives a much lower result. Turning now to the seven and twenty-eight day tests of briquets maintained at the ordinary temperature, it is seen that W gave in every case higher results than T, and nearly as high as U or V. Among the short time tests it is only the results of briquets maintained at 80° C. that indicate the inferiority of Brand W.

Table 40. Interpretation Of Short Time Tests Of Portland Cement, Several Brands